1 # SPDX-License-Identifier: GPL-2.0+
2 #
3 # (C) Copyright 2000 - 2013
4 # Wolfgang Denk, DENX Software Engineering, wd (a] denx.de.
5
6 Summary:
7 ========
8
9 This directory contains the source code for U-Boot, a boot loader for
10 Embedded boards based on PowerPC, ARM, MIPS and several other
11 processors, which can be installed in a boot ROM and used to
12 initialize and test the hardware or to download and run application
13 code.
14
15 The development of U-Boot is closely related to Linux: some parts of
16 the source code originate in the Linux source tree, we have some
17 header files in common, and special provision has been made to
18 support booting of Linux images.
19
20 Some attention has been paid to make this software easily
21 configurable and extendable. For instance, all monitor commands are
22 implemented with the same call interface, so that it's very easy to
23 add new commands. Also, instead of permanently adding rarely used
24 code (for instance hardware test utilities) to the monitor, you can
25 load and run it dynamically.
26
27
28 Status:
29 =======
30
31 In general, all boards for which a configuration option exists in the
32 Makefile have been tested to some extent and can be considered
33 "working". In fact, many of them are used in production systems.
34
35 In case of problems see the CHANGELOG file to find out who contributed
36 the specific port. In addition, there are various MAINTAINERS files
37 scattered throughout the U-Boot source identifying the people or
38 companies responsible for various boards and subsystems.
39
40 Note: As of August, 2010, there is no longer a CHANGELOG file in the
41 actual U-Boot source tree; however, it can be created dynamically
42 from the Git log using:
43
44 make CHANGELOG
45
46
47 Where to get help:
48 ==================
49
50 In case you have questions about, problems with or contributions for
51 U-Boot, you should send a message to the U-Boot mailing list at
52 <u-boot (a] lists.denx.de>. There is also an archive of previous traffic
53 on the mailing list - please search the archive before asking FAQ's.
54 Please see http://lists.denx.de/pipermail/u-boot and
55 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
56
57
58 Where to get source code:
59 =========================
60
61 The U-Boot source code is maintained in the Git repository at
62 git://www.denx.de/git/u-boot.git ; you can browse it online at
63 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
64
65 The "snapshot" links on this page allow you to download tarballs of
66 any version you might be interested in. Official releases are also
67 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
68 directory.
69
70 Pre-built (and tested) images are available from
71 ftp://ftp.denx.de/pub/u-boot/images/
72
73
74 Where we come from:
75 ===================
76
77 - start from 8xxrom sources
78 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
79 - clean up code
80 - make it easier to add custom boards
81 - make it possible to add other [PowerPC] CPUs
82 - extend functions, especially:
83 * Provide extended interface to Linux boot loader
84 * S-Record download
85 * network boot
86 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
87 - create ARMBoot project (http://sourceforge.net/projects/armboot)
88 - add other CPU families (starting with ARM)
89 - create U-Boot project (http://sourceforge.net/projects/u-boot)
90 - current project page: see http://www.denx.de/wiki/U-Boot
91
92
93 Names and Spelling:
94 ===================
95
96 The "official" name of this project is "Das U-Boot". The spelling
97 "U-Boot" shall be used in all written text (documentation, comments
98 in source files etc.). Example:
99
100 This is the README file for the U-Boot project.
101
102 File names etc. shall be based on the string "u-boot". Examples:
103
104 include/asm-ppc/u-boot.h
105
106 #include <asm/u-boot.h>
107
108 Variable names, preprocessor constants etc. shall be either based on
109 the string "u_boot" or on "U_BOOT". Example:
110
111 U_BOOT_VERSION u_boot_logo
112 IH_OS_U_BOOT u_boot_hush_start
113
114
115 Versioning:
116 ===========
117
118 Starting with the release in October 2008, the names of the releases
119 were changed from numerical release numbers without deeper meaning
120 into a time stamp based numbering. Regular releases are identified by
121 names consisting of the calendar year and month of the release date.
122 Additional fields (if present) indicate release candidates or bug fix
123 releases in "stable" maintenance trees.
124
125 Examples:
126 U-Boot v2009.11 - Release November 2009
127 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
128 U-Boot v2010.09-rc1 - Release candidate 1 for September 2010 release
129
130
131 Directory Hierarchy:
132 ====================
133
134 /arch Architecture specific files
135 /arc Files generic to ARC architecture
136 /arm Files generic to ARM architecture
137 /m68k Files generic to m68k architecture
138 /microblaze Files generic to microblaze architecture
139 /mips Files generic to MIPS architecture
140 /nds32 Files generic to NDS32 architecture
141 /nios2 Files generic to Altera NIOS2 architecture
142 /openrisc Files generic to OpenRISC architecture
143 /powerpc Files generic to PowerPC architecture
144 /riscv Files generic to RISC-V architecture
145 /sandbox Files generic to HW-independent "sandbox"
146 /sh Files generic to SH architecture
147 /x86 Files generic to x86 architecture
148 /api Machine/arch independent API for external apps
149 /board Board dependent files
150 /cmd U-Boot commands functions
151 /common Misc architecture independent functions
152 /configs Board default configuration files
153 /disk Code for disk drive partition handling
154 /doc Documentation (don't expect too much)
155 /drivers Commonly used device drivers
156 /dts Contains Makefile for building internal U-Boot fdt.
157 /examples Example code for standalone applications, etc.
158 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
159 /include Header Files
160 /lib Library routines generic to all architectures
161 /Licenses Various license files
162 /net Networking code
163 /post Power On Self Test
164 /scripts Various build scripts and Makefiles
165 /test Various unit test files
166 /tools Tools to build S-Record or U-Boot images, etc.
167
168 Software Configuration:
169 =======================
170
171 Configuration is usually done using C preprocessor defines; the
172 rationale behind that is to avoid dead code whenever possible.
173
174 There are two classes of configuration variables:
175
176 * Configuration _OPTIONS_:
177 These are selectable by the user and have names beginning with
178 "CONFIG_".
179
180 * Configuration _SETTINGS_:
181 These depend on the hardware etc. and should not be meddled with if
182 you don't know what you're doing; they have names beginning with
183 "CONFIG_SYS_".
184
185 Previously, all configuration was done by hand, which involved creating
186 symbolic links and editing configuration files manually. More recently,
187 U-Boot has added the Kbuild infrastructure used by the Linux kernel,
188 allowing you to use the "make menuconfig" command to configure your
189 build.
190
191
192 Selection of Processor Architecture and Board Type:
193 ---------------------------------------------------
194
195 For all supported boards there are ready-to-use default
196 configurations available; just type "make <board_name>_defconfig".
197
198 Example: For a TQM823L module type:
199
200 cd u-boot
201 make TQM823L_defconfig
202
203 Note: If you're looking for the default configuration file for a board
204 you're sure used to be there but is now missing, check the file
205 doc/README.scrapyard for a list of no longer supported boards.
206
207 Sandbox Environment:
208 --------------------
209
210 U-Boot can be built natively to run on a Linux host using the 'sandbox'
211 board. This allows feature development which is not board- or architecture-
212 specific to be undertaken on a native platform. The sandbox is also used to
213 run some of U-Boot's tests.
214
215 See board/sandbox/README.sandbox for more details.
216
217
218 Board Initialisation Flow:
219 --------------------------
220
221 This is the intended start-up flow for boards. This should apply for both
222 SPL and U-Boot proper (i.e. they both follow the same rules).
223
224 Note: "SPL" stands for "Secondary Program Loader," which is explained in
225 more detail later in this file.
226
227 At present, SPL mostly uses a separate code path, but the function names
228 and roles of each function are the same. Some boards or architectures
229 may not conform to this. At least most ARM boards which use
230 CONFIG_SPL_FRAMEWORK conform to this.
231
232 Execution typically starts with an architecture-specific (and possibly
233 CPU-specific) start.S file, such as:
234
235 - arch/arm/cpu/armv7/start.S
236 - arch/powerpc/cpu/mpc83xx/start.S
237 - arch/mips/cpu/start.S
238
239 and so on. From there, three functions are called; the purpose and
240 limitations of each of these functions are described below.
241
242 lowlevel_init():
243 - purpose: essential init to permit execution to reach board_init_f()
244 - no global_data or BSS
245 - there is no stack (ARMv7 may have one but it will soon be removed)
246 - must not set up SDRAM or use console
247 - must only do the bare minimum to allow execution to continue to
248 board_init_f()
249 - this is almost never needed
250 - return normally from this function
251
252 board_init_f():
253 - purpose: set up the machine ready for running board_init_r():
254 i.e. SDRAM and serial UART
255 - global_data is available
256 - stack is in SRAM
257 - BSS is not available, so you cannot use global/static variables,
258 only stack variables and global_data
259
260 Non-SPL-specific notes:
261 - dram_init() is called to set up DRAM. If already done in SPL this
262 can do nothing
263
264 SPL-specific notes:
265 - you can override the entire board_init_f() function with your own
266 version as needed.
267 - preloader_console_init() can be called here in extremis
268 - should set up SDRAM, and anything needed to make the UART work
269 - these is no need to clear BSS, it will be done by crt0.S
270 - must return normally from this function (don't call board_init_r()
271 directly)
272
273 Here the BSS is cleared. For SPL, if CONFIG_SPL_STACK_R is defined, then at
274 this point the stack and global_data are relocated to below
275 CONFIG_SPL_STACK_R_ADDR. For non-SPL, U-Boot is relocated to run at the top of
276 memory.
277
278 board_init_r():
279 - purpose: main execution, common code
280 - global_data is available
281 - SDRAM is available
282 - BSS is available, all static/global variables can be used
283 - execution eventually continues to main_loop()
284
285 Non-SPL-specific notes:
286 - U-Boot is relocated to the top of memory and is now running from
287 there.
288
289 SPL-specific notes:
290 - stack is optionally in SDRAM, if CONFIG_SPL_STACK_R is defined and
291 CONFIG_SPL_STACK_R_ADDR points into SDRAM
292 - preloader_console_init() can be called here - typically this is
293 done by selecting CONFIG_SPL_BOARD_INIT and then supplying a
294 spl_board_init() function containing this call
295 - loads U-Boot or (in falcon mode) Linux
296
297
298
299 Configuration Options:
300 ----------------------
301
302 Configuration depends on the combination of board and CPU type; all
303 such information is kept in a configuration file
304 "include/configs/<board_name>.h".
305
306 Example: For a TQM823L module, all configuration settings are in
307 "include/configs/TQM823L.h".
308
309
310 Many of the options are named exactly as the corresponding Linux
311 kernel configuration options. The intention is to make it easier to
312 build a config tool - later.
313
314 - ARM Platform Bus Type(CCI):
315 CoreLink Cache Coherent Interconnect (CCI) is ARM BUS which
316 provides full cache coherency between two clusters of multi-core
317 CPUs and I/O coherency for devices and I/O masters
318
319 CONFIG_SYS_FSL_HAS_CCI400
320
321 Defined For SoC that has cache coherent interconnect
322 CCN-400
323
324 CONFIG_SYS_FSL_HAS_CCN504
325
326 Defined for SoC that has cache coherent interconnect CCN-504
327
328 The following options need to be configured:
329
330 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
331
332 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
333
334 - 85xx CPU Options:
335 CONFIG_SYS_PPC64
336
337 Specifies that the core is a 64-bit PowerPC implementation (implements
338 the "64" category of the Power ISA). This is necessary for ePAPR
339 compliance, among other possible reasons.
340
341 CONFIG_SYS_FSL_TBCLK_DIV
342
343 Defines the core time base clock divider ratio compared to the
344 system clock. On most PQ3 devices this is 8, on newer QorIQ
345 devices it can be 16 or 32. The ratio varies from SoC to Soc.
346
347 CONFIG_SYS_FSL_PCIE_COMPAT
348
349 Defines the string to utilize when trying to match PCIe device
350 tree nodes for the given platform.
351
352 CONFIG_SYS_FSL_ERRATUM_A004510
353
354 Enables a workaround for erratum A004510. If set,
355 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
356 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
357
358 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
359 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
360
361 Defines one or two SoC revisions (low 8 bits of SVR)
362 for which the A004510 workaround should be applied.
363
364 The rest of SVR is either not relevant to the decision
365 of whether the erratum is present (e.g. p2040 versus
366 p2041) or is implied by the build target, which controls
367 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
368
369 See Freescale App Note 4493 for more information about
370 this erratum.
371
372 CONFIG_A003399_NOR_WORKAROUND
373 Enables a workaround for IFC erratum A003399. It is only
374 required during NOR boot.
375
376 CONFIG_A008044_WORKAROUND
377 Enables a workaround for T1040/T1042 erratum A008044. It is only
378 required during NAND boot and valid for Rev 1.0 SoC revision
379
380 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
381
382 This is the value to write into CCSR offset 0x18600
383 according to the A004510 workaround.
384
385 CONFIG_SYS_FSL_DSP_DDR_ADDR
386 This value denotes start offset of DDR memory which is
387 connected exclusively to the DSP cores.
388
389 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
390 This value denotes start offset of M2 memory
391 which is directly connected to the DSP core.
392
393 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
394 This value denotes start offset of M3 memory which is directly
395 connected to the DSP core.
396
397 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
398 This value denotes start offset of DSP CCSR space.
399
400 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
401 Single Source Clock is clocking mode present in some of FSL SoC's.
402 In this mode, a single differential clock is used to supply
403 clocks to the sysclock, ddrclock and usbclock.
404
405 CONFIG_SYS_CPC_REINIT_F
406 This CONFIG is defined when the CPC is configured as SRAM at the
407 time of U-Boot entry and is required to be re-initialized.
408
409 CONFIG_DEEP_SLEEP
410 Indicates this SoC supports deep sleep feature. If deep sleep is
411 supported, core will start to execute uboot when wakes up.
412
413 - Generic CPU options:
414 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
415
416 Defines the endianess of the CPU. Implementation of those
417 values is arch specific.
418
419 CONFIG_SYS_FSL_DDR
420 Freescale DDR driver in use. This type of DDR controller is
421 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
422 SoCs.
423
424 CONFIG_SYS_FSL_DDR_ADDR
425 Freescale DDR memory-mapped register base.
426
427 CONFIG_SYS_FSL_DDR_EMU
428 Specify emulator support for DDR. Some DDR features such as
429 deskew training are not available.
430
431 CONFIG_SYS_FSL_DDRC_GEN1
432 Freescale DDR1 controller.
433
434 CONFIG_SYS_FSL_DDRC_GEN2
435 Freescale DDR2 controller.
436
437 CONFIG_SYS_FSL_DDRC_GEN3
438 Freescale DDR3 controller.
439
440 CONFIG_SYS_FSL_DDRC_GEN4
441 Freescale DDR4 controller.
442
443 CONFIG_SYS_FSL_DDRC_ARM_GEN3
444 Freescale DDR3 controller for ARM-based SoCs.
445
446 CONFIG_SYS_FSL_DDR1
447 Board config to use DDR1. It can be enabled for SoCs with
448 Freescale DDR1 or DDR2 controllers, depending on the board
449 implemetation.
450
451 CONFIG_SYS_FSL_DDR2
452 Board config to use DDR2. It can be enabled for SoCs with
453 Freescale DDR2 or DDR3 controllers, depending on the board
454 implementation.
455
456 CONFIG_SYS_FSL_DDR3
457 Board config to use DDR3. It can be enabled for SoCs with
458 Freescale DDR3 or DDR3L controllers.
459
460 CONFIG_SYS_FSL_DDR3L
461 Board config to use DDR3L. It can be enabled for SoCs with
462 DDR3L controllers.
463
464 CONFIG_SYS_FSL_DDR4
465 Board config to use DDR4. It can be enabled for SoCs with
466 DDR4 controllers.
467
468 CONFIG_SYS_FSL_IFC_BE
469 Defines the IFC controller register space as Big Endian
470
471 CONFIG_SYS_FSL_IFC_LE
472 Defines the IFC controller register space as Little Endian
473
474 CONFIG_SYS_FSL_IFC_CLK_DIV
475 Defines divider of platform clock(clock input to IFC controller).
476
477 CONFIG_SYS_FSL_LBC_CLK_DIV
478 Defines divider of platform clock(clock input to eLBC controller).
479
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
483
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
488
489 CONFIG_SPL_FSL_PBL
490 It adds a target to create boot binary having SPL binary in PBI format
491 concatenated with u-boot binary.
492
493 CONFIG_SYS_FSL_DDR_BE
494 Defines the DDR controller register space as Big Endian
495
496 CONFIG_SYS_FSL_DDR_LE
497 Defines the DDR controller register space as Little Endian
498
499 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
500 Physical address from the view of DDR controllers. It is the
501 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
502 it could be different for ARM SoCs.
503
504 CONFIG_SYS_FSL_DDR_INTLV_256B
505 DDR controller interleaving on 256-byte. This is a special
506 interleaving mode, handled by Dickens for Freescale layerscape
507 SoCs with ARM core.
508
509 CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS
510 Number of controllers used as main memory.
511
512 CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
513 Number of controllers used for other than main memory.
514
515 CONFIG_SYS_FSL_HAS_DP_DDR
516 Defines the SoC has DP-DDR used for DPAA.
517
518 CONFIG_SYS_FSL_SEC_BE
519 Defines the SEC controller register space as Big Endian
520
521 CONFIG_SYS_FSL_SEC_LE
522 Defines the SEC controller register space as Little Endian
523
524 - MIPS CPU options:
525 CONFIG_SYS_INIT_SP_OFFSET
526
527 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
528 pointer. This is needed for the temporary stack before
529 relocation.
530
531 CONFIG_SYS_MIPS_CACHE_MODE
532
533 Cache operation mode for the MIPS CPU.
534 See also arch/mips/include/asm/mipsregs.h.
535 Possible values are:
536 CONF_CM_CACHABLE_NO_WA
537 CONF_CM_CACHABLE_WA
538 CONF_CM_UNCACHED
539 CONF_CM_CACHABLE_NONCOHERENT
540 CONF_CM_CACHABLE_CE
541 CONF_CM_CACHABLE_COW
542 CONF_CM_CACHABLE_CUW
543 CONF_CM_CACHABLE_ACCELERATED
544
545 CONFIG_SYS_XWAY_EBU_BOOTCFG
546
547 Special option for Lantiq XWAY SoCs for booting from NOR flash.
548 See also arch/mips/cpu/mips32/start.S.
549
550 CONFIG_XWAY_SWAP_BYTES
551
552 Enable compilation of tools/xway-swap-bytes needed for Lantiq
553 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
554 be swapped if a flash programmer is used.
555
556 - ARM options:
557 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
558
559 Select high exception vectors of the ARM core, e.g., do not
560 clear the V bit of the c1 register of CP15.
561
562 COUNTER_FREQUENCY
563 Generic timer clock source frequency.
564
565 COUNTER_FREQUENCY_REAL
566 Generic timer clock source frequency if the real clock is
567 different from COUNTER_FREQUENCY, and can only be determined
568 at run time.
569
570 - Tegra SoC options:
571 CONFIG_TEGRA_SUPPORT_NON_SECURE
572
573 Support executing U-Boot in non-secure (NS) mode. Certain
574 impossible actions will be skipped if the CPU is in NS mode,
575 such as ARM architectural timer initialization.
576
577 - Linux Kernel Interface:
578 CONFIG_CLOCKS_IN_MHZ
579
580 U-Boot stores all clock information in Hz
581 internally. For binary compatibility with older Linux
582 kernels (which expect the clocks passed in the
583 bd_info data to be in MHz) the environment variable
584 "clocks_in_mhz" can be defined so that U-Boot
585 converts clock data to MHZ before passing it to the
586 Linux kernel.
587 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
588 "clocks_in_mhz=1" is automatically included in the
589 default environment.
590
591 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
592
593 When transferring memsize parameter to Linux, some versions
594 expect it to be in bytes, others in MB.
595 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
596
597 CONFIG_OF_LIBFDT
598
599 New kernel versions are expecting firmware settings to be
600 passed using flattened device trees (based on open firmware
601 concepts).
602
603 CONFIG_OF_LIBFDT
604 * New libfdt-based support
605 * Adds the "fdt" command
606 * The bootm command automatically updates the fdt
607
608 OF_TBCLK - The timebase frequency.
609 OF_STDOUT_PATH - The path to the console device
610
611 boards with QUICC Engines require OF_QE to set UCC MAC
612 addresses
613
614 CONFIG_OF_BOARD_SETUP
615
616 Board code has addition modification that it wants to make
617 to the flat device tree before handing it off to the kernel
618
619 CONFIG_OF_SYSTEM_SETUP
620
621 Other code has addition modification that it wants to make
622 to the flat device tree before handing it off to the kernel.
623 This causes ft_system_setup() to be called before booting
624 the kernel.
625
626 CONFIG_OF_IDE_FIXUP
627
628 U-Boot can detect if an IDE device is present or not.
629 If not, and this new config option is activated, U-Boot
630 removes the ATA node from the DTS before booting Linux,
631 so the Linux IDE driver does not probe the device and
632 crash. This is needed for buggy hardware (uc101) where
633 no pull down resistor is connected to the signal IDE5V_DD7.
634
635 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
636
637 This setting is mandatory for all boards that have only one
638 machine type and must be used to specify the machine type
639 number as it appears in the ARM machine registry
640 (see http://www.arm.linux.org.uk/developer/machines/).
641 Only boards that have multiple machine types supported
642 in a single configuration file and the machine type is
643 runtime discoverable, do not have to use this setting.
644
645 - vxWorks boot parameters:
646
647 bootvx constructs a valid bootline using the following
648 environments variables: bootdev, bootfile, ipaddr, netmask,
649 serverip, gatewayip, hostname, othbootargs.
650 It loads the vxWorks image pointed bootfile.
651
652 Note: If a "bootargs" environment is defined, it will overwride
653 the defaults discussed just above.
654
655 - Cache Configuration:
656 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
657 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
658 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
659
660 - Cache Configuration for ARM:
661 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
662 controller
663 CONFIG_SYS_PL310_BASE - Physical base address of PL310
664 controller register space
665
666 - Serial Ports:
667 CONFIG_PL010_SERIAL
668
669 Define this if you want support for Amba PrimeCell PL010 UARTs.
670
671 CONFIG_PL011_SERIAL
672
673 Define this if you want support for Amba PrimeCell PL011 UARTs.
674
675 CONFIG_PL011_CLOCK
676
677 If you have Amba PrimeCell PL011 UARTs, set this variable to
678 the clock speed of the UARTs.
679
680 CONFIG_PL01x_PORTS
681
682 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
683 define this to a list of base addresses for each (supported)
684 port. See e.g. include/configs/versatile.h
685
686 CONFIG_SERIAL_HW_FLOW_CONTROL
687
688 Define this variable to enable hw flow control in serial driver.
689 Current user of this option is drivers/serial/nsl16550.c driver
690
691 - Console Baudrate:
692 CONFIG_BAUDRATE - in bps
693 Select one of the baudrates listed in
694 CONFIG_SYS_BAUDRATE_TABLE, see below.
695
696 - Autoboot Command:
697 CONFIG_BOOTCOMMAND
698 Only needed when CONFIG_BOOTDELAY is enabled;
699 define a command string that is automatically executed
700 when no character is read on the console interface
701 within "Boot Delay" after reset.
702
703 CONFIG_RAMBOOT and CONFIG_NFSBOOT
704 The value of these goes into the environment as
705 "ramboot" and "nfsboot" respectively, and can be used
706 as a convenience, when switching between booting from
707 RAM and NFS.
708
709 - Pre-Boot Commands:
710 CONFIG_PREBOOT
711
712 When this option is #defined, the existence of the
713 environment variable "preboot" will be checked
714 immediately before starting the CONFIG_BOOTDELAY
715 countdown and/or running the auto-boot command resp.
716 entering interactive mode.
717
718 This feature is especially useful when "preboot" is
719 automatically generated or modified. For an example
720 see the LWMON board specific code: here "preboot" is
721 modified when the user holds down a certain
722 combination of keys on the (special) keyboard when
723 booting the systems
724
725 - Serial Download Echo Mode:
726 CONFIG_LOADS_ECHO
727 If defined to 1, all characters received during a
728 serial download (using the "loads" command) are
729 echoed back. This might be needed by some terminal
730 emulations (like "cu"), but may as well just take
731 time on others. This setting #define's the initial
732 value of the "loads_echo" environment variable.
733
734 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
735 CONFIG_KGDB_BAUDRATE
736 Select one of the baudrates listed in
737 CONFIG_SYS_BAUDRATE_TABLE, see below.
738
739 - Removal of commands
740 If no commands are needed to boot, you can disable
741 CONFIG_CMDLINE to remove them. In this case, the command line
742 will not be available, and when U-Boot wants to execute the
743 boot command (on start-up) it will call board_run_command()
744 instead. This can reduce image size significantly for very
745 simple boot procedures.
746
747 - Regular expression support:
748 CONFIG_REGEX
749 If this variable is defined, U-Boot is linked against
750 the SLRE (Super Light Regular Expression) library,
751 which adds regex support to some commands, as for
752 example "env grep" and "setexpr".
753
754 - Device tree:
755 CONFIG_OF_CONTROL
756 If this variable is defined, U-Boot will use a device tree
757 to configure its devices, instead of relying on statically
758 compiled #defines in the board file. This option is
759 experimental and only available on a few boards. The device
760 tree is available in the global data as gd->fdt_blob.
761
762 U-Boot needs to get its device tree from somewhere. This can
763 be done using one of the three options below:
764
765 CONFIG_OF_EMBED
766 If this variable is defined, U-Boot will embed a device tree
767 binary in its image. This device tree file should be in the
768 board directory and called <soc>-<board>.dts. The binary file
769 is then picked up in board_init_f() and made available through
770 the global data structure as gd->fdt_blob.
771
772 CONFIG_OF_SEPARATE
773 If this variable is defined, U-Boot will build a device tree
774 binary. It will be called u-boot.dtb. Architecture-specific
775 code will locate it at run-time. Generally this works by:
776
777 cat u-boot.bin u-boot.dtb >image.bin
778
779 and in fact, U-Boot does this for you, creating a file called
780 u-boot-dtb.bin which is useful in the common case. You can
781 still use the individual files if you need something more
782 exotic.
783
784 CONFIG_OF_BOARD
785 If this variable is defined, U-Boot will use the device tree
786 provided by the board at runtime instead of embedding one with
787 the image. Only boards defining board_fdt_blob_setup() support
788 this option (see include/fdtdec.h file).
789
790 - Watchdog:
791 CONFIG_WATCHDOG
792 If this variable is defined, it enables watchdog
793 support for the SoC. There must be support in the SoC
794 specific code for a watchdog. For the 8xx
795 CPUs, the SIU Watchdog feature is enabled in the SYPCR
796 register. When supported for a specific SoC is
797 available, then no further board specific code should
798 be needed to use it.
799
800 CONFIG_HW_WATCHDOG
801 When using a watchdog circuitry external to the used
802 SoC, then define this variable and provide board
803 specific code for the "hw_watchdog_reset" function.
804
805 CONFIG_AT91_HW_WDT_TIMEOUT
806 specify the timeout in seconds. default 2 seconds.
807
808 - Real-Time Clock:
809
810 When CONFIG_CMD_DATE is selected, the type of the RTC
811 has to be selected, too. Define exactly one of the
812 following options:
813
814 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
815 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
816 CONFIG_RTC_MC146818 - use MC146818 RTC
817 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
818 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
819 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
820 CONFIG_RTC_DS1339 - use Maxim, Inc. DS1339 RTC
821 CONFIG_RTC_DS164x - use Dallas DS164x RTC
822 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
823 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
824 CONFIG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
825 CONFIG_SYS_RV3029_TCR - enable trickle charger on
826 RV3029 RTC.
827
828 Note that if the RTC uses I2C, then the I2C interface
829 must also be configured. See I2C Support, below.
830
831 - GPIO Support:
832 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
833
834 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
835 chip-ngpio pairs that tell the PCA953X driver the number of
836 pins supported by a particular chip.
837
838 Note that if the GPIO device uses I2C, then the I2C interface
839 must also be configured. See I2C Support, below.
840
841 - I/O tracing:
842 When CONFIG_IO_TRACE is selected, U-Boot intercepts all I/O
843 accesses and can checksum them or write a list of them out
844 to memory. See the 'iotrace' command for details. This is
845 useful for testing device drivers since it can confirm that
846 the driver behaves the same way before and after a code
847 change. Currently this is supported on sandbox and arm. To
848 add support for your architecture, add '#include <iotrace.h>'
849 to the bottom of arch/<arch>/include/asm/io.h and test.
850
851 Example output from the 'iotrace stats' command is below.
852 Note that if the trace buffer is exhausted, the checksum will
853 still continue to operate.
854
855 iotrace is enabled
856 Start: 10000000 (buffer start address)
857 Size: 00010000 (buffer size)
858 Offset: 00000120 (current buffer offset)
859 Output: 10000120 (start + offset)
860 Count: 00000018 (number of trace records)
861 CRC32: 9526fb66 (CRC32 of all trace records)
862
863 - Timestamp Support:
864
865 When CONFIG_TIMESTAMP is selected, the timestamp
866 (date and time) of an image is printed by image
867 commands like bootm or iminfo. This option is
868 automatically enabled when you select CONFIG_CMD_DATE .
869
870 - Partition Labels (disklabels) Supported:
871 Zero or more of the following:
872 CONFIG_MAC_PARTITION Apple's MacOS partition table.
873 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
874 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
875 bootloader. Note 2TB partition limit; see
876 disk/part_efi.c
877 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
878
879 If IDE or SCSI support is enabled (CONFIG_IDE or
880 CONFIG_SCSI) you must configure support for at
881 least one non-MTD partition type as well.
882
883 - IDE Reset method:
884 CONFIG_IDE_RESET_ROUTINE - this is defined in several
885 board configurations files but used nowhere!
886
887 CONFIG_IDE_RESET - is this is defined, IDE Reset will
888 be performed by calling the function
889 ide_set_reset(int reset)
890 which has to be defined in a board specific file
891
892 - ATAPI Support:
893 CONFIG_ATAPI
894
895 Set this to enable ATAPI support.
896
897 - LBA48 Support
898 CONFIG_LBA48
899
900 Set this to enable support for disks larger than 137GB
901 Also look at CONFIG_SYS_64BIT_LBA.
902 Whithout these , LBA48 support uses 32bit variables and will 'only'
903 support disks up to 2.1TB.
904
905 CONFIG_SYS_64BIT_LBA:
906 When enabled, makes the IDE subsystem use 64bit sector addresses.
907 Default is 32bit.
908
909 - SCSI Support:
910 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
911 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
912 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
913 maximum numbers of LUNs, SCSI ID's and target
914 devices.
915
916 The environment variable 'scsidevs' is set to the number of
917 SCSI devices found during the last scan.
918
919 - NETWORK Support (PCI):
920 CONFIG_E1000
921 Support for Intel 8254x/8257x gigabit chips.
922
923 CONFIG_E1000_SPI
924 Utility code for direct access to the SPI bus on Intel 8257x.
925 This does not do anything useful unless you set at least one
926 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
927
928 CONFIG_E1000_SPI_GENERIC
929 Allow generic access to the SPI bus on the Intel 8257x, for
930 example with the "sspi" command.
931
932 CONFIG_EEPRO100
933 Support for Intel 82557/82559/82559ER chips.
934 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
935 write routine for first time initialisation.
936
937 CONFIG_TULIP
938 Support for Digital 2114x chips.
939 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
940 modem chip initialisation (KS8761/QS6611).
941
942 CONFIG_NATSEMI
943 Support for National dp83815 chips.
944
945 CONFIG_NS8382X
946 Support for National dp8382[01] gigabit chips.
947
948 - NETWORK Support (other):
949
950 CONFIG_DRIVER_AT91EMAC
951 Support for AT91RM9200 EMAC.
952
953 CONFIG_RMII
954 Define this to use reduced MII inteface
955
956 CONFIG_DRIVER_AT91EMAC_QUIET
957 If this defined, the driver is quiet.
958 The driver doen't show link status messages.
959
960 CONFIG_CALXEDA_XGMAC
961 Support for the Calxeda XGMAC device
962
963 CONFIG_LAN91C96
964 Support for SMSC's LAN91C96 chips.
965
966 CONFIG_LAN91C96_USE_32_BIT
967 Define this to enable 32 bit addressing
968
969 CONFIG_SMC91111
970 Support for SMSC's LAN91C111 chip
971
972 CONFIG_SMC91111_BASE
973 Define this to hold the physical address
974 of the device (I/O space)
975
976 CONFIG_SMC_USE_32_BIT
977 Define this if data bus is 32 bits
978
979 CONFIG_SMC_USE_IOFUNCS
980 Define this to use i/o functions instead of macros
981 (some hardware wont work with macros)
982
983 CONFIG_DRIVER_TI_EMAC
984 Support for davinci emac
985
986 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
987 Define this if you have more then 3 PHYs.
988
989 CONFIG_FTGMAC100
990 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
991
992 CONFIG_FTGMAC100_EGIGA
993 Define this to use GE link update with gigabit PHY.
994 Define this if FTGMAC100 is connected to gigabit PHY.
995 If your system has 10/100 PHY only, it might not occur
996 wrong behavior. Because PHY usually return timeout or
997 useless data when polling gigabit status and gigabit
998 control registers. This behavior won't affect the
999 correctnessof 10/100 link speed update.
1000
1001 CONFIG_SH_ETHER
1002 Support for Renesas on-chip Ethernet controller
1003
1004 CONFIG_SH_ETHER_USE_PORT
1005 Define the number of ports to be used
1006
1007 CONFIG_SH_ETHER_PHY_ADDR
1008 Define the ETH PHY's address
1009
1010 CONFIG_SH_ETHER_CACHE_WRITEBACK
1011 If this option is set, the driver enables cache flush.
1012
1013 - PWM Support:
1014 CONFIG_PWM_IMX
1015 Support for PWM module on the imx6.
1016
1017 - TPM Support:
1018 CONFIG_TPM
1019 Support TPM devices.
1020
1021 CONFIG_TPM_TIS_INFINEON
1022 Support for Infineon i2c bus TPM devices. Only one device
1023 per system is supported at this time.
1024
1025 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1026 Define the burst count bytes upper limit
1027
1028 CONFIG_TPM_ST33ZP24
1029 Support for STMicroelectronics TPM devices. Requires DM_TPM support.
1030
1031 CONFIG_TPM_ST33ZP24_I2C
1032 Support for STMicroelectronics ST33ZP24 I2C devices.
1033 Requires TPM_ST33ZP24 and I2C.
1034
1035 CONFIG_TPM_ST33ZP24_SPI
1036 Support for STMicroelectronics ST33ZP24 SPI devices.
1037 Requires TPM_ST33ZP24 and SPI.
1038
1039 CONFIG_TPM_ATMEL_TWI
1040 Support for Atmel TWI TPM device. Requires I2C support.
1041
1042 CONFIG_TPM_TIS_LPC
1043 Support for generic parallel port TPM devices. Only one device
1044 per system is supported at this time.
1045
1046 CONFIG_TPM_TIS_BASE_ADDRESS
1047 Base address where the generic TPM device is mapped
1048 to. Contemporary x86 systems usually map it at
1049 0xfed40000.
1050
1051 CONFIG_TPM
1052 Define this to enable the TPM support library which provides
1053 functional interfaces to some TPM commands.
1054 Requires support for a TPM device.
1055
1056 CONFIG_TPM_AUTH_SESSIONS
1057 Define this to enable authorized functions in the TPM library.
1058 Requires CONFIG_TPM and CONFIG_SHA1.
1059
1060 - USB Support:
1061 At the moment only the UHCI host controller is
1062 supported (PIP405, MIP405); define
1063 CONFIG_USB_UHCI to enable it.
1064 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1065 and define CONFIG_USB_STORAGE to enable the USB
1066 storage devices.
1067 Note:
1068 Supported are USB Keyboards and USB Floppy drives
1069 (TEAC FD-05PUB).
1070
1071 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1072 txfilltuning field in the EHCI controller on reset.
1073
1074 CONFIG_USB_DWC2_REG_ADDR the physical CPU address of the DWC2
1075 HW module registers.
1076
1077 - USB Device:
1078 Define the below if you wish to use the USB console.
1079 Once firmware is rebuilt from a serial console issue the
1080 command "setenv stdin usbtty; setenv stdout usbtty" and
1081 attach your USB cable. The Unix command "dmesg" should print
1082 it has found a new device. The environment variable usbtty
1083 can be set to gserial or cdc_acm to enable your device to
1084 appear to a USB host as a Linux gserial device or a
1085 Common Device Class Abstract Control Model serial device.
1086 If you select usbtty = gserial you should be able to enumerate
1087 a Linux host by
1088 # modprobe usbserial vendor=0xVendorID product=0xProductID
1089 else if using cdc_acm, simply setting the environment
1090 variable usbtty to be cdc_acm should suffice. The following
1091 might be defined in YourBoardName.h
1092
1093 CONFIG_USB_DEVICE
1094 Define this to build a UDC device
1095
1096 CONFIG_USB_TTY
1097 Define this to have a tty type of device available to
1098 talk to the UDC device
1099
1100 CONFIG_USBD_HS
1101 Define this to enable the high speed support for usb
1102 device and usbtty. If this feature is enabled, a routine
1103 int is_usbd_high_speed(void)
1104 also needs to be defined by the driver to dynamically poll
1105 whether the enumeration has succeded at high speed or full
1106 speed.
1107
1108 CONFIG_SYS_CONSOLE_IS_IN_ENV
1109 Define this if you want stdin, stdout &/or stderr to
1110 be set to usbtty.
1111
1112 If you have a USB-IF assigned VendorID then you may wish to
1113 define your own vendor specific values either in BoardName.h
1114 or directly in usbd_vendor_info.h. If you don't define
1115 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1116 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1117 should pretend to be a Linux device to it's target host.
1118
1119 CONFIG_USBD_MANUFACTURER
1120 Define this string as the name of your company for
1121 - CONFIG_USBD_MANUFACTURER "my company"
1122
1123 CONFIG_USBD_PRODUCT_NAME
1124 Define this string as the name of your product
1125 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1126
1127 CONFIG_USBD_VENDORID
1128 Define this as your assigned Vendor ID from the USB
1129 Implementors Forum. This *must* be a genuine Vendor ID
1130 to avoid polluting the USB namespace.
1131 - CONFIG_USBD_VENDORID 0xFFFF
1132
1133 CONFIG_USBD_PRODUCTID
1134 Define this as the unique Product ID
1135 for your device
1136 - CONFIG_USBD_PRODUCTID 0xFFFF
1137
1138 - ULPI Layer Support:
1139 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1140 the generic ULPI layer. The generic layer accesses the ULPI PHY
1141 via the platform viewport, so you need both the genric layer and
1142 the viewport enabled. Currently only Chipidea/ARC based
1143 viewport is supported.
1144 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1145 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1146 If your ULPI phy needs a different reference clock than the
1147 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1148 the appropriate value in Hz.
1149
1150 - MMC Support:
1151 The MMC controller on the Intel PXA is supported. To
1152 enable this define CONFIG_MMC. The MMC can be
1153 accessed from the boot prompt by mapping the device
1154 to physical memory similar to flash. Command line is
1155 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1156 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1157
1158 CONFIG_SH_MMCIF
1159 Support for Renesas on-chip MMCIF controller
1160
1161 CONFIG_SH_MMCIF_ADDR
1162 Define the base address of MMCIF registers
1163
1164 CONFIG_SH_MMCIF_CLK
1165 Define the clock frequency for MMCIF
1166
1167 CONFIG_SUPPORT_EMMC_BOOT
1168 Enable some additional features of the eMMC boot partitions.
1169
1170 - USB Device Firmware Update (DFU) class support:
1171 CONFIG_DFU_OVER_USB
1172 This enables the USB portion of the DFU USB class
1173
1174 CONFIG_DFU_MMC
1175 This enables support for exposing (e)MMC devices via DFU.
1176
1177 CONFIG_DFU_NAND
1178 This enables support for exposing NAND devices via DFU.
1179
1180 CONFIG_DFU_RAM
1181 This enables support for exposing RAM via DFU.
1182 Note: DFU spec refer to non-volatile memory usage, but
1183 allow usages beyond the scope of spec - here RAM usage,
1184 one that would help mostly the developer.
1185
1186 CONFIG_SYS_DFU_DATA_BUF_SIZE
1187 Dfu transfer uses a buffer before writing data to the
1188 raw storage device. Make the size (in bytes) of this buffer
1189 configurable. The size of this buffer is also configurable
1190 through the "dfu_bufsiz" environment variable.
1191
1192 CONFIG_SYS_DFU_MAX_FILE_SIZE
1193 When updating files rather than the raw storage device,
1194 we use a static buffer to copy the file into and then write
1195 the buffer once we've been given the whole file. Define
1196 this to the maximum filesize (in bytes) for the buffer.
1197 Default is 4 MiB if undefined.
1198
1199 DFU_DEFAULT_POLL_TIMEOUT
1200 Poll timeout [ms], is the timeout a device can send to the
1201 host. The host must wait for this timeout before sending
1202 a subsequent DFU_GET_STATUS request to the device.
1203
1204 DFU_MANIFEST_POLL_TIMEOUT
1205 Poll timeout [ms], which the device sends to the host when
1206 entering dfuMANIFEST state. Host waits this timeout, before
1207 sending again an USB request to the device.
1208
1209 - Android Bootloader support:
1210 CONFIG_CMD_BOOT_ANDROID
1211 This enables the command "boot_android" which executes the
1212 Android Bootloader flow. Enabling CONFIG_CMD_FASTBOOT is
1213 recommended to support the Android Fastboot protocol as part
1214 of the bootloader.
1215
1216 CONFIG_ANDROID_BOOTLOADER
1217 This enables support for the Android bootloader flow. Android
1218 devices can boot in normal mode, recovery mode or bootloader
1219 mode. The normal mode is the most common boot mode, but
1220 recovery mode is often used to perform factory reset and OTA
1221 (over-the-air) updates in the legacy updater. Also it is
1222 possible for an Android system to request a reboot to the
1223 "bootloader", which often means reboot to fastboot but may also
1224 include a UI with a menu.
1225
1226 - Journaling Flash filesystem support:
1227 CONFIG_JFFS2_NAND
1228 Define these for a default partition on a NAND device
1229
1230 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1231 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1232 Define these for a default partition on a NOR device
1233
1234 - Keyboard Support:
1235 See Kconfig help for available keyboard drivers.
1236
1237 CONFIG_KEYBOARD
1238
1239 Define this to enable a custom keyboard support.
1240 This simply calls drv_keyboard_init() which must be
1241 defined in your board-specific files. This option is deprecated
1242 and is only used by novena. For new boards, use driver model
1243 instead.
1244
1245 - Video support:
1246 CONFIG_FSL_DIU_FB
1247 Enable the Freescale DIU video driver. Reference boards for
1248 SOCs that have a DIU should define this macro to enable DIU
1249 support, and should also define these other macros:
1250
1251 CONFIG_SYS_DIU_ADDR
1252 CONFIG_VIDEO
1253 CONFIG_CFB_CONSOLE
1254 CONFIG_VIDEO_SW_CURSOR
1255 CONFIG_VGA_AS_SINGLE_DEVICE
1256 CONFIG_VIDEO_LOGO
1257 CONFIG_VIDEO_BMP_LOGO
1258
1259 The DIU driver will look for the 'video-mode' environment
1260 variable, and if defined, enable the DIU as a console during
1261 boot. See the documentation file doc/README.video for a
1262 description of this variable.
1263
1264 - LCD Support: CONFIG_LCD
1265
1266 Define this to enable LCD support (for output to LCD
1267 display); also select one of the supported displays
1268 by defining one of these:
1269
1270 CONFIG_ATMEL_LCD:
1271
1272 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1273
1274 CONFIG_NEC_NL6448AC33:
1275
1276 NEC NL6448AC33-18. Active, color, single scan.
1277
1278 CONFIG_NEC_NL6448BC20
1279
1280 NEC NL6448BC20-08. 6.5", 640x480.
1281 Active, color, single scan.
1282
1283 CONFIG_NEC_NL6448BC33_54
1284
1285 NEC NL6448BC33-54. 10.4", 640x480.
1286 Active, color, single scan.
1287
1288 CONFIG_SHARP_16x9
1289
1290 Sharp 320x240. Active, color, single scan.
1291 It isn't 16x9, and I am not sure what it is.
1292
1293 CONFIG_SHARP_LQ64D341
1294
1295 Sharp LQ64D341 display, 640x480.
1296 Active, color, single scan.
1297
1298 CONFIG_HLD1045
1299
1300 HLD1045 display, 640x480.
1301 Active, color, single scan.
1302
1303 CONFIG_OPTREX_BW
1304
1305 Optrex CBL50840-2 NF-FW 99 22 M5
1306 or
1307 Hitachi LMG6912RPFC-00T
1308 or
1309 Hitachi SP14Q002
1310
1311 320x240. Black & white.
1312
1313 CONFIG_LCD_ALIGNMENT
1314
1315 Normally the LCD is page-aligned (typically 4KB). If this is
1316 defined then the LCD will be aligned to this value instead.
1317 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1318 here, since it is cheaper to change data cache settings on
1319 a per-section basis.
1320
1321
1322 CONFIG_LCD_ROTATION
1323
1324 Sometimes, for example if the display is mounted in portrait
1325 mode or even if it's mounted landscape but rotated by 180degree,
1326 we need to rotate our content of the display relative to the
1327 framebuffer, so that user can read the messages which are
1328 printed out.
1329 Once CONFIG_LCD_ROTATION is defined, the lcd_console will be
1330 initialized with a given rotation from "vl_rot" out of
1331 "vidinfo_t" which is provided by the board specific code.
1332 The value for vl_rot is coded as following (matching to
1333 fbcon=rotate:<n> linux-kernel commandline):
1334 0 = no rotation respectively 0 degree
1335 1 = 90 degree rotation
1336 2 = 180 degree rotation
1337 3 = 270 degree rotation
1338
1339 If CONFIG_LCD_ROTATION is not defined, the console will be
1340 initialized with 0degree rotation.
1341
1342 CONFIG_LCD_BMP_RLE8
1343
1344 Support drawing of RLE8-compressed bitmaps on the LCD.
1345
1346 CONFIG_I2C_EDID
1347
1348 Enables an 'i2c edid' command which can read EDID
1349 information over I2C from an attached LCD display.
1350
1351 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1352
1353 If this option is set, the environment is checked for
1354 a variable "splashimage". If found, the usual display
1355 of logo, copyright and system information on the LCD
1356 is suppressed and the BMP image at the address
1357 specified in "splashimage" is loaded instead. The
1358 console is redirected to the "nulldev", too. This
1359 allows for a "silent" boot where a splash screen is
1360 loaded very quickly after power-on.
1361
1362 CONFIG_SPLASHIMAGE_GUARD
1363
1364 If this option is set, then U-Boot will prevent the environment
1365 variable "splashimage" from being set to a problematic address
1366 (see doc/README.displaying-bmps).
1367 This option is useful for targets where, due to alignment
1368 restrictions, an improperly aligned BMP image will cause a data
1369 abort. If you think you will not have problems with unaligned
1370 accesses (for example because your toolchain prevents them)
1371 there is no need to set this option.
1372
1373 CONFIG_SPLASH_SCREEN_ALIGN
1374
1375 If this option is set the splash image can be freely positioned
1376 on the screen. Environment variable "splashpos" specifies the
1377 position as "x,y". If a positive number is given it is used as
1378 number of pixel from left/top. If a negative number is given it
1379 is used as number of pixel from right/bottom. You can also
1380 specify 'm' for centering the image.
1381
1382 Example:
1383 setenv splashpos m,m
1384 => image at center of screen
1385
1386 setenv splashpos 30,20
1387 => image at x = 30 and y = 20
1388
1389 setenv splashpos -10,m
1390 => vertically centered image
1391 at x = dspWidth - bmpWidth - 9
1392
1393 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1394
1395 If this option is set, additionally to standard BMP
1396 images, gzipped BMP images can be displayed via the
1397 splashscreen support or the bmp command.
1398
1399 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1400
1401 If this option is set, 8-bit RLE compressed BMP images
1402 can be displayed via the splashscreen support or the
1403 bmp command.
1404
1405 - Compression support:
1406 CONFIG_GZIP
1407
1408 Enabled by default to support gzip compressed images.
1409
1410 CONFIG_BZIP2
1411
1412 If this option is set, support for bzip2 compressed
1413 images is included. If not, only uncompressed and gzip
1414 compressed images are supported.
1415
1416 NOTE: the bzip2 algorithm requires a lot of RAM, so
1417 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1418 be at least 4MB.
1419
1420 - MII/PHY support:
1421 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1422
1423 The clock frequency of the MII bus
1424
1425 CONFIG_PHY_RESET_DELAY
1426
1427 Some PHY like Intel LXT971A need extra delay after
1428 reset before any MII register access is possible.
1429 For such PHY, set this option to the usec delay
1430 required. (minimum 300usec for LXT971A)
1431
1432 CONFIG_PHY_CMD_DELAY (ppc4xx)
1433
1434 Some PHY like Intel LXT971A need extra delay after
1435 command issued before MII status register can be read
1436
1437 - IP address:
1438 CONFIG_IPADDR
1439
1440 Define a default value for the IP address to use for
1441 the default Ethernet interface, in case this is not
1442 determined through e.g. bootp.
1443 (Environment variable "ipaddr")
1444
1445 - Server IP address:
1446 CONFIG_SERVERIP
1447
1448 Defines a default value for the IP address of a TFTP
1449 server to contact when using the "tftboot" command.
1450 (Environment variable "serverip")
1451
1452 CONFIG_KEEP_SERVERADDR
1453
1454 Keeps the server's MAC address, in the env 'serveraddr'
1455 for passing to bootargs (like Linux's netconsole option)
1456
1457 - Gateway IP address:
1458 CONFIG_GATEWAYIP
1459
1460 Defines a default value for the IP address of the
1461 default router where packets to other networks are
1462 sent to.
1463 (Environment variable "gatewayip")
1464
1465 - Subnet mask:
1466 CONFIG_NETMASK
1467
1468 Defines a default value for the subnet mask (or
1469 routing prefix) which is used to determine if an IP
1470 address belongs to the local subnet or needs to be
1471 forwarded through a router.
1472 (Environment variable "netmask")
1473
1474 - Multicast TFTP Mode:
1475 CONFIG_MCAST_TFTP
1476
1477 Defines whether you want to support multicast TFTP as per
1478 rfc-2090; for example to work with atftp. Lets lots of targets
1479 tftp down the same boot image concurrently. Note: the Ethernet
1480 driver in use must provide a function: mcast() to join/leave a
1481 multicast group.
1482
1483 - BOOTP Recovery Mode:
1484 CONFIG_BOOTP_RANDOM_DELAY
1485
1486 If you have many targets in a network that try to
1487 boot using BOOTP, you may want to avoid that all
1488 systems send out BOOTP requests at precisely the same
1489 moment (which would happen for instance at recovery
1490 from a power failure, when all systems will try to
1491 boot, thus flooding the BOOTP server. Defining
1492 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1493 inserted before sending out BOOTP requests. The
1494 following delays are inserted then:
1495
1496 1st BOOTP request: delay 0 ... 1 sec
1497 2nd BOOTP request: delay 0 ... 2 sec
1498 3rd BOOTP request: delay 0 ... 4 sec
1499 4th and following
1500 BOOTP requests: delay 0 ... 8 sec
1501
1502 CONFIG_BOOTP_ID_CACHE_SIZE
1503
1504 BOOTP packets are uniquely identified using a 32-bit ID. The
1505 server will copy the ID from client requests to responses and
1506 U-Boot will use this to determine if it is the destination of
1507 an incoming response. Some servers will check that addresses
1508 aren't in use before handing them out (usually using an ARP
1509 ping) and therefore take up to a few hundred milliseconds to
1510 respond. Network congestion may also influence the time it
1511 takes for a response to make it back to the client. If that
1512 time is too long, U-Boot will retransmit requests. In order
1513 to allow earlier responses to still be accepted after these
1514 retransmissions, U-Boot's BOOTP client keeps a small cache of
1515 IDs. The CONFIG_BOOTP_ID_CACHE_SIZE controls the size of this
1516 cache. The default is to keep IDs for up to four outstanding
1517 requests. Increasing this will allow U-Boot to accept offers
1518 from a BOOTP client in networks with unusually high latency.
1519
1520 - DHCP Advanced Options:
1521 You can fine tune the DHCP functionality by defining
1522 CONFIG_BOOTP_* symbols:
1523
1524 CONFIG_BOOTP_NISDOMAIN
1525 CONFIG_BOOTP_BOOTFILESIZE
1526 CONFIG_BOOTP_SEND_HOSTNAME
1527 CONFIG_BOOTP_NTPSERVER
1528 CONFIG_BOOTP_TIMEOFFSET
1529 CONFIG_BOOTP_VENDOREX
1530 CONFIG_BOOTP_MAY_FAIL
1531
1532 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1533 environment variable, not the BOOTP server.
1534
1535 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1536 after the configured retry count, the call will fail
1537 instead of starting over. This can be used to fail over
1538 to Link-local IP address configuration if the DHCP server
1539 is not available.
1540
1541 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1542 to do a dynamic update of a DNS server. To do this, they
1543 need the hostname of the DHCP requester.
1544 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1545 of the "hostname" environment variable is passed as
1546 option 12 to the DHCP server.
1547
1548 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1549
1550 A 32bit value in microseconds for a delay between
1551 receiving a "DHCP Offer" and sending the "DHCP Request".
1552 This fixes a problem with certain DHCP servers that don't
1553 respond 100% of the time to a "DHCP request". E.g. On an
1554 AT91RM9200 processor running at 180MHz, this delay needed
1555 to be *at least* 15,000 usec before a Windows Server 2003
1556 DHCP server would reply 100% of the time. I recommend at
1557 least 50,000 usec to be safe. The alternative is to hope
1558 that one of the retries will be successful but note that
1559 the DHCP timeout and retry process takes a longer than
1560 this delay.
1561
1562 - Link-local IP address negotiation:
1563 Negotiate with other link-local clients on the local network
1564 for an address that doesn't require explicit configuration.
1565 This is especially useful if a DHCP server cannot be guaranteed
1566 to exist in all environments that the device must operate.
1567
1568 See doc/README.link-local for more information.
1569
1570 - MAC address from environment variables
1571
1572 FDT_SEQ_MACADDR_FROM_ENV
1573
1574 Fix-up device tree with MAC addresses fetched sequentially from
1575 environment variables. This config work on assumption that
1576 non-usable ethernet node of device-tree are either not present
1577 or their status has been marked as "disabled".
1578
1579 - CDP Options:
1580 CONFIG_CDP_DEVICE_ID
1581
1582 The device id used in CDP trigger frames.
1583
1584 CONFIG_CDP_DEVICE_ID_PREFIX
1585
1586 A two character string which is prefixed to the MAC address
1587 of the device.
1588
1589 CONFIG_CDP_PORT_ID
1590
1591 A printf format string which contains the ascii name of
1592 the port. Normally is set to "eth%d" which sets
1593 eth0 for the first Ethernet, eth1 for the second etc.
1594
1595 CONFIG_CDP_CAPABILITIES
1596
1597 A 32bit integer which indicates the device capabilities;
1598 0x00000010 for a normal host which does not forwards.
1599
1600 CONFIG_CDP_VERSION
1601
1602 An ascii string containing the version of the software.
1603
1604 CONFIG_CDP_PLATFORM
1605
1606 An ascii string containing the name of the platform.
1607
1608 CONFIG_CDP_TRIGGER
1609
1610 A 32bit integer sent on the trigger.
1611
1612 CONFIG_CDP_POWER_CONSUMPTION
1613
1614 A 16bit integer containing the power consumption of the
1615 device in .1 of milliwatts.
1616
1617 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1618
1619 A byte containing the id of the VLAN.
1620
1621 - Status LED: CONFIG_LED_STATUS
1622
1623 Several configurations allow to display the current
1624 status using a LED. For instance, the LED will blink
1625 fast while running U-Boot code, stop blinking as
1626 soon as a reply to a BOOTP request was received, and
1627 start blinking slow once the Linux kernel is running
1628 (supported by a status LED driver in the Linux
1629 kernel). Defining CONFIG_LED_STATUS enables this
1630 feature in U-Boot.
1631
1632 Additional options:
1633
1634 CONFIG_LED_STATUS_GPIO
1635 The status LED can be connected to a GPIO pin.
1636 In such cases, the gpio_led driver can be used as a
1637 status LED backend implementation. Define CONFIG_LED_STATUS_GPIO
1638 to include the gpio_led driver in the U-Boot binary.
1639
1640 CONFIG_GPIO_LED_INVERTED_TABLE
1641 Some GPIO connected LEDs may have inverted polarity in which
1642 case the GPIO high value corresponds to LED off state and
1643 GPIO low value corresponds to LED on state.
1644 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
1645 with a list of GPIO LEDs that have inverted polarity.
1646
1647 - I2C Support: CONFIG_SYS_I2C
1648
1649 This enable the NEW i2c subsystem, and will allow you to use
1650 i2c commands at the u-boot command line (as long as you set
1651 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
1652 based realtime clock chips or other i2c devices. See
1653 common/cmd_i2c.c for a description of the command line
1654 interface.
1655
1656 ported i2c driver to the new framework:
1657 - drivers/i2c/soft_i2c.c:
1658 - activate first bus with CONFIG_SYS_I2C_SOFT define
1659 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
1660 for defining speed and slave address
1661 - activate second bus with I2C_SOFT_DECLARATIONS2 define
1662 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
1663 for defining speed and slave address
1664 - activate third bus with I2C_SOFT_DECLARATIONS3 define
1665 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
1666 for defining speed and slave address
1667 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
1668 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
1669 for defining speed and slave address
1670
1671 - drivers/i2c/fsl_i2c.c:
1672 - activate i2c driver with CONFIG_SYS_I2C_FSL
1673 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
1674 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
1675 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
1676 bus.
1677 - If your board supports a second fsl i2c bus, define
1678 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
1679 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
1680 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
1681 second bus.
1682
1683 - drivers/i2c/tegra_i2c.c:
1684 - activate this driver with CONFIG_SYS_I2C_TEGRA
1685 - This driver adds 4 i2c buses with a fix speed from
1686 100000 and the slave addr 0!
1687
1688 - drivers/i2c/ppc4xx_i2c.c
1689 - activate this driver with CONFIG_SYS_I2C_PPC4XX
1690 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
1691 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
1692
1693 - drivers/i2c/i2c_mxc.c
1694 - activate this driver with CONFIG_SYS_I2C_MXC
1695 - enable bus 1 with CONFIG_SYS_I2C_MXC_I2C1
1696 - enable bus 2 with CONFIG_SYS_I2C_MXC_I2C2
1697 - enable bus 3 with CONFIG_SYS_I2C_MXC_I2C3
1698 - enable bus 4 with CONFIG_SYS_I2C_MXC_I2C4
1699 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
1700 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
1701 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
1702 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
1703 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
1704 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
1705 - define speed for bus 4 with CONFIG_SYS_MXC_I2C4_SPEED
1706 - define slave for bus 4 with CONFIG_SYS_MXC_I2C4_SLAVE
1707 If those defines are not set, default value is 100000
1708 for speed, and 0 for slave.
1709
1710 - drivers/i2c/rcar_i2c.c:
1711 - activate this driver with CONFIG_SYS_I2C_RCAR
1712 - This driver adds 4 i2c buses
1713
1714 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
1715 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
1716 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
1717 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
1718 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
1719 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
1720 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
1721 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
1722 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
1723
1724 - drivers/i2c/sh_i2c.c:
1725 - activate this driver with CONFIG_SYS_I2C_SH
1726 - This driver adds from 2 to 5 i2c buses
1727
1728 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
1729 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
1730 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
1731 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
1732 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
1733 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
1734 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
1735 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
1736 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
1737 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
1738 - CONFIG_SYS_I2C_SH_NUM_CONTROLLERS for number of i2c buses
1739
1740 - drivers/i2c/omap24xx_i2c.c
1741 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
1742 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
1743 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
1744 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
1745 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
1746 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
1747 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
1748 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
1749 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
1750 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
1751 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
1752
1753 - drivers/i2c/zynq_i2c.c
1754 - activate this driver with CONFIG_SYS_I2C_ZYNQ
1755 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
1756 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
1757
1758 - drivers/i2c/s3c24x0_i2c.c:
1759 - activate this driver with CONFIG_SYS_I2C_S3C24X0
1760 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
1761 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
1762 with a fix speed from 100000 and the slave addr 0!
1763
1764 - drivers/i2c/ihs_i2c.c
1765 - activate this driver with CONFIG_SYS_I2C_IHS
1766 - CONFIG_SYS_I2C_IHS_CH0 activate hardware channel 0
1767 - CONFIG_SYS_I2C_IHS_SPEED_0 speed channel 0
1768 - CONFIG_SYS_I2C_IHS_SLAVE_0 slave addr channel 0
1769 - CONFIG_SYS_I2C_IHS_CH1 activate hardware channel 1
1770 - CONFIG_SYS_I2C_IHS_SPEED_1 speed channel 1
1771 - CONFIG_SYS_I2C_IHS_SLAVE_1 slave addr channel 1
1772 - CONFIG_SYS_I2C_IHS_CH2 activate hardware channel 2
1773 - CONFIG_SYS_I2C_IHS_SPEED_2 speed channel 2
1774 - CONFIG_SYS_I2C_IHS_SLAVE_2 slave addr channel 2
1775 - CONFIG_SYS_I2C_IHS_CH3 activate hardware channel 3
1776 - CONFIG_SYS_I2C_IHS_SPEED_3 speed channel 3
1777 - CONFIG_SYS_I2C_IHS_SLAVE_3 slave addr channel 3
1778 - activate dual channel with CONFIG_SYS_I2C_IHS_DUAL
1779 - CONFIG_SYS_I2C_IHS_SPEED_0_1 speed channel 0_1
1780 - CONFIG_SYS_I2C_IHS_SLAVE_0_1 slave addr channel 0_1
1781 - CONFIG_SYS_I2C_IHS_SPEED_1_1 speed channel 1_1
1782 - CONFIG_SYS_I2C_IHS_SLAVE_1_1 slave addr channel 1_1
1783 - CONFIG_SYS_I2C_IHS_SPEED_2_1 speed channel 2_1
1784 - CONFIG_SYS_I2C_IHS_SLAVE_2_1 slave addr channel 2_1
1785 - CONFIG_SYS_I2C_IHS_SPEED_3_1 speed channel 3_1
1786 - CONFIG_SYS_I2C_IHS_SLAVE_3_1 slave addr channel 3_1
1787
1788 additional defines:
1789
1790 CONFIG_SYS_NUM_I2C_BUSES
1791 Hold the number of i2c buses you want to use.
1792
1793 CONFIG_SYS_I2C_DIRECT_BUS
1794 define this, if you don't use i2c muxes on your hardware.
1795 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
1796 omit this define.
1797
1798 CONFIG_SYS_I2C_MAX_HOPS
1799 define how many muxes are maximal consecutively connected
1800 on one i2c bus. If you not use i2c muxes, omit this
1801 define.
1802
1803 CONFIG_SYS_I2C_BUSES
1804 hold a list of buses you want to use, only used if
1805 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
1806 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
1807 CONFIG_SYS_NUM_I2C_BUSES = 9:
1808
1809 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
1810 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
1811 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
1812 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
1813 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
1814 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
1815 {1, {I2C_NULL_HOP}}, \
1816 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
1817 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
1818 }
1819
1820 which defines
1821 bus 0 on adapter 0 without a mux
1822 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
1823 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
1824 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
1825 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
1826 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
1827 bus 6 on adapter 1 without a mux
1828 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
1829 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
1830
1831 If you do not have i2c muxes on your board, omit this define.
1832
1833 - Legacy I2C Support:
1834 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
1835 then the following macros need to be defined (examples are
1836 from include/configs/lwmon.h):
1837
1838 I2C_INIT
1839
1840 (Optional). Any commands necessary to enable the I2C
1841 controller or configure ports.
1842
1843 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1844
1845 I2C_ACTIVE
1846
1847 The code necessary to make the I2C data line active
1848 (driven). If the data line is open collector, this
1849 define can be null.
1850
1851 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1852
1853 I2C_TRISTATE
1854
1855 The code necessary to make the I2C data line tri-stated
1856 (inactive). If the data line is open collector, this
1857 define can be null.
1858
1859 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1860
1861 I2C_READ
1862
1863 Code that returns true if the I2C data line is high,
1864 false if it is low.
1865
1866 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1867
1868 I2C_SDA(bit)
1869
1870 If <bit> is true, sets the I2C data line high. If it
1871 is false, it clears it (low).
1872
1873 eg: #define I2C_SDA(bit) \
1874 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1875 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1876
1877 I2C_SCL(bit)
1878
1879 If <bit> is true, sets the I2C clock line high. If it
1880 is false, it clears it (low).
1881
1882 eg: #define I2C_SCL(bit) \
1883 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1884 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1885
1886 I2C_DELAY
1887
1888 This delay is invoked four times per clock cycle so this
1889 controls the rate of data transfer. The data rate thus
1890 is 1 / (I2C_DELAY * 4). Often defined to be something
1891 like:
1892
1893 #define I2C_DELAY udelay(2)
1894
1895 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1896
1897 If your arch supports the generic GPIO framework (asm/gpio.h),
1898 then you may alternatively define the two GPIOs that are to be
1899 used as SCL / SDA. Any of the previous I2C_xxx macros will
1900 have GPIO-based defaults assigned to them as appropriate.
1901
1902 You should define these to the GPIO value as given directly to
1903 the generic GPIO functions.
1904
1905 CONFIG_SYS_I2C_INIT_BOARD
1906
1907 When a board is reset during an i2c bus transfer
1908 chips might think that the current transfer is still
1909 in progress. On some boards it is possible to access
1910 the i2c SCLK line directly, either by using the
1911 processor pin as a GPIO or by having a second pin
1912 connected to the bus. If this option is defined a
1913 custom i2c_init_board() routine in boards/xxx/board.c
1914 is run early in the boot sequence.
1915
1916 CONFIG_I2C_MULTI_BUS
1917
1918 This option allows the use of multiple I2C buses, each of which
1919 must have a controller. At any point in time, only one bus is
1920 active. To switch to a different bus, use the 'i2c dev' command.
1921 Note that bus numbering is zero-based.
1922
1923 CONFIG_SYS_I2C_NOPROBES
1924
1925 This option specifies a list of I2C devices that will be skipped
1926 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1927 is set, specify a list of bus-device pairs. Otherwise, specify
1928 a 1D array of device addresses
1929
1930 e.g.
1931 #undef CONFIG_I2C_MULTI_BUS
1932 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1933
1934 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1935
1936 #define CONFIG_I2C_MULTI_BUS
1937 #define CONFIG_SYS_I2C_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1938
1939 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1940
1941 CONFIG_SYS_SPD_BUS_NUM
1942
1943 If defined, then this indicates the I2C bus number for DDR SPD.
1944 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1945
1946 CONFIG_SYS_RTC_BUS_NUM
1947
1948 If defined, then this indicates the I2C bus number for the RTC.
1949 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1950
1951 CONFIG_SOFT_I2C_READ_REPEATED_START
1952
1953 defining this will force the i2c_read() function in
1954 the soft_i2c driver to perform an I2C repeated start
1955 between writing the address pointer and reading the
1956 data. If this define is omitted the default behaviour
1957 of doing a stop-start sequence will be used. Most I2C
1958 devices can use either method, but some require one or
1959 the other.
1960
1961 - SPI Support: CONFIG_SPI
1962
1963 Enables SPI driver (so far only tested with
1964 SPI EEPROM, also an instance works with Crystal A/D and
1965 D/As on the SACSng board)
1966
1967 CONFIG_SOFT_SPI
1968
1969 Enables a software (bit-bang) SPI driver rather than
1970 using hardware support. This is a general purpose
1971 driver that only requires three general I/O port pins
1972 (two outputs, one input) to function. If this is
1973 defined, the board configuration must define several
1974 SPI configuration items (port pins to use, etc). For
1975 an example, see include/configs/sacsng.h.
1976
1977 CONFIG_HARD_SPI
1978
1979 Enables a hardware SPI driver for general-purpose reads
1980 and writes. As with CONFIG_SOFT_SPI, the board configuration
1981 must define a list of chip-select function pointers.
1982 Currently supported on some MPC8xxx processors. For an
1983 example, see include/configs/mpc8349emds.h.
1984
1985 CONFIG_SYS_SPI_MXC_WAIT
1986 Timeout for waiting until spi transfer completed.
1987 default: (CONFIG_SYS_HZ/100) /* 10 ms */
1988
1989 - FPGA Support: CONFIG_FPGA
1990
1991 Enables FPGA subsystem.
1992
1993 CONFIG_FPGA_<vendor>
1994
1995 Enables support for specific chip vendors.
1996 (ALTERA, XILINX)
1997
1998 CONFIG_FPGA_<family>
1999
2000 Enables support for FPGA family.
2001 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2002
2003 CONFIG_FPGA_COUNT
2004
2005 Specify the number of FPGA devices to support.
2006
2007 CONFIG_SYS_FPGA_PROG_FEEDBACK
2008
2009 Enable printing of hash marks during FPGA configuration.
2010
2011 CONFIG_SYS_FPGA_CHECK_BUSY
2012
2013 Enable checks on FPGA configuration interface busy
2014 status by the configuration function. This option
2015 will require a board or device specific function to
2016 be written.
2017
2018 CONFIG_FPGA_DELAY
2019
2020 If defined, a function that provides delays in the FPGA
2021 configuration driver.
2022
2023 CONFIG_SYS_FPGA_CHECK_CTRLC
2024 Allow Control-C to interrupt FPGA configuration
2025
2026 CONFIG_SYS_FPGA_CHECK_ERROR
2027
2028 Check for configuration errors during FPGA bitfile
2029 loading. For example, abort during Virtex II
2030 configuration if the INIT_B line goes low (which
2031 indicated a CRC error).
2032
2033 CONFIG_SYS_FPGA_WAIT_INIT
2034
2035 Maximum time to wait for the INIT_B line to de-assert
2036 after PROB_B has been de-asserted during a Virtex II
2037 FPGA configuration sequence. The default time is 500
2038 ms.
2039
2040 CONFIG_SYS_FPGA_WAIT_BUSY
2041
2042 Maximum time to wait for BUSY to de-assert during
2043 Virtex II FPGA configuration. The default is 5 ms.
2044
2045 CONFIG_SYS_FPGA_WAIT_CONFIG
2046
2047 Time to wait after FPGA configuration. The default is
2048 200 ms.
2049
2050 - Configuration Management:
2051 CONFIG_BUILD_TARGET
2052
2053 Some SoCs need special image types (e.g. U-Boot binary
2054 with a special header) as build targets. By defining
2055 CONFIG_BUILD_TARGET in the SoC / board header, this
2056 special image will be automatically built upon calling
2057 make / buildman.
2058
2059 CONFIG_IDENT_STRING
2060
2061 If defined, this string will be added to the U-Boot
2062 version information (U_BOOT_VERSION)
2063
2064 - Vendor Parameter Protection:
2065
2066 U-Boot considers the values of the environment
2067 variables "serial#" (Board Serial Number) and
2068 "ethaddr" (Ethernet Address) to be parameters that
2069 are set once by the board vendor / manufacturer, and
2070 protects these variables from casual modification by
2071 the user. Once set, these variables are read-only,
2072 and write or delete attempts are rejected. You can
2073 change this behaviour:
2074
2075 If CONFIG_ENV_OVERWRITE is #defined in your config
2076 file, the write protection for vendor parameters is
2077 completely disabled. Anybody can change or delete
2078 these parameters.
2079
2080 Alternatively, if you define _both_ an ethaddr in the
2081 default env _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2082 Ethernet address is installed in the environment,
2083 which can be changed exactly ONCE by the user. [The
2084 serial# is unaffected by this, i. e. it remains
2085 read-only.]
2086
2087 The same can be accomplished in a more flexible way
2088 for any variable by configuring the type of access
2089 to allow for those variables in the ".flags" variable
2090 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2091
2092 - Protected RAM:
2093 CONFIG_PRAM
2094
2095 Define this variable to enable the reservation of
2096 "protected RAM", i. e. RAM which is not overwritten
2097 by U-Boot. Define CONFIG_PRAM to hold the number of
2098 kB you want to reserve for pRAM. You can overwrite
2099 this default value by defining an environment
2100 variable "pram" to the number of kB you want to
2101 reserve. Note that the board info structure will
2102 still show the full amount of RAM. If pRAM is
2103 reserved, a new environment variable "mem" will
2104 automatically be defined to hold the amount of
2105 remaining RAM in a form that can be passed as boot
2106 argument to Linux, for instance like that:
2107
2108 setenv bootargs ... mem=\${mem}
2109 saveenv
2110
2111 This way you can tell Linux not to use this memory,
2112 either, which results in a memory region that will
2113 not be affected by reboots.
2114
2115 *WARNING* If your board configuration uses automatic
2116 detection of the RAM size, you must make sure that
2117 this memory test is non-destructive. So far, the
2118 following board configurations are known to be
2119 "pRAM-clean":
2120
2121 IVMS8, IVML24, SPD8xx,
2122 HERMES, IP860, RPXlite, LWMON,
2123 FLAGADM
2124
2125 - Access to physical memory region (> 4GB)
2126 Some basic support is provided for operations on memory not
2127 normally accessible to U-Boot - e.g. some architectures
2128 support access to more than 4GB of memory on 32-bit
2129 machines using physical address extension or similar.
2130 Define CONFIG_PHYSMEM to access this basic support, which
2131 currently only supports clearing the memory.
2132
2133 - Error Recovery:
2134 CONFIG_NET_RETRY_COUNT
2135
2136 This variable defines the number of retries for
2137 network operations like ARP, RARP, TFTP, or BOOTP
2138 before giving up the operation. If not defined, a
2139 default value of 5 is used.
2140
2141 CONFIG_ARP_TIMEOUT
2142
2143 Timeout waiting for an ARP reply in milliseconds.
2144
2145 CONFIG_NFS_TIMEOUT
2146
2147 Timeout in milliseconds used in NFS protocol.
2148 If you encounter "ERROR: Cannot umount" in nfs command,
2149 try longer timeout such as
2150 #define CONFIG_NFS_TIMEOUT 10000UL
2151
2152 - Command Interpreter:
2153 CONFIG_SYS_PROMPT_HUSH_PS2
2154
2155 This defines the secondary prompt string, which is
2156 printed when the command interpreter needs more input
2157 to complete a command. Usually "> ".
2158
2159 Note:
2160
2161 In the current implementation, the local variables
2162 space and global environment variables space are
2163 separated. Local variables are those you define by
2164 simply typing `name=value'. To access a local
2165 variable later on, you have write `$name' or
2166 `${name}'; to execute the contents of a variable
2167 directly type `$name' at the command prompt.
2168
2169 Global environment variables are those you use
2170 setenv/printenv to work with. To run a command stored
2171 in such a variable, you need to use the run command,
2172 and you must not use the '$' sign to access them.
2173
2174 To store commands and special characters in a
2175 variable, please use double quotation marks
2176 surrounding the whole text of the variable, instead
2177 of the backslashes before semicolons and special
2178 symbols.
2179
2180 - Command Line Editing and History:
2181 CONFIG_CMDLINE_PS_SUPPORT
2182
2183 Enable support for changing the command prompt string
2184 at run-time. Only static string is supported so far.
2185 The string is obtained from environment variables PS1
2186 and PS2.
2187
2188 - Default Environment:
2189 CONFIG_EXTRA_ENV_SETTINGS
2190
2191 Define this to contain any number of null terminated
2192 strings (variable = value pairs) that will be part of
2193 the default environment compiled into the boot image.
2194
2195 For example, place something like this in your
2196 board's config file:
2197
2198 #define CONFIG_EXTRA_ENV_SETTINGS \
2199 "myvar1=value1\0" \
2200 "myvar2=value2\0"
2201
2202 Warning: This method is based on knowledge about the
2203 internal format how the environment is stored by the
2204 U-Boot code. This is NOT an official, exported
2205 interface! Although it is unlikely that this format
2206 will change soon, there is no guarantee either.
2207 You better know what you are doing here.
2208
2209 Note: overly (ab)use of the default environment is
2210 discouraged. Make sure to check other ways to preset
2211 the environment like the "source" command or the
2212 boot command first.
2213
2214 CONFIG_DELAY_ENVIRONMENT
2215
2216 Normally the environment is loaded when the board is
2217 initialised so that it is available to U-Boot. This inhibits
2218 that so that the environment is not available until
2219 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2220 this is instead controlled by the value of
2221 /config/load-environment.
2222
2223 - Serial Flash support
2224 Usage requires an initial 'sf probe' to define the serial
2225 flash parameters, followed by read/write/erase/update
2226 commands.
2227
2228 The following defaults may be provided by the platform
2229 to handle the common case when only a single serial
2230 flash is present on the system.
2231
2232 CONFIG_SF_DEFAULT_BUS Bus identifier
2233 CONFIG_SF_DEFAULT_CS Chip-select
2234 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2235 CONFIG_SF_DEFAULT_SPEED in Hz
2236
2237
2238 - TFTP Fixed UDP Port:
2239 CONFIG_TFTP_PORT
2240
2241 If this is defined, the environment variable tftpsrcp
2242 is used to supply the TFTP UDP source port value.
2243 If tftpsrcp isn't defined, the normal pseudo-random port
2244 number generator is used.
2245
2246 Also, the environment variable tftpdstp is used to supply
2247 the TFTP UDP destination port value. If tftpdstp isn't
2248 defined, the normal port 69 is used.
2249
2250 The purpose for tftpsrcp is to allow a TFTP server to
2251 blindly start the TFTP transfer using the pre-configured
2252 target IP address and UDP port. This has the effect of
2253 "punching through" the (Windows XP) firewall, allowing
2254 the remainder of the TFTP transfer to proceed normally.
2255 A better solution is to properly configure the firewall,
2256 but sometimes that is not allowed.
2257
2258 - Show boot progress:
2259 CONFIG_SHOW_BOOT_PROGRESS
2260
2261 Defining this option allows to add some board-
2262 specific code (calling a user-provided function
2263 "show_boot_progress(int)") that enables you to show
2264 the system's boot progress on some display (for
2265 example, some LED's) on your board. At the moment,
2266 the following checkpoints are implemented:
2267
2268
2269 Legacy uImage format:
2270
2271 Arg Where When
2272 1 common/cmd_bootm.c before attempting to boot an image
2273 -1 common/cmd_bootm.c Image header has bad magic number
2274 2 common/cmd_bootm.c Image header has correct magic number
2275 -2 common/cmd_bootm.c Image header has bad checksum
2276 3 common/cmd_bootm.c Image header has correct checksum
2277 -3 common/cmd_bootm.c Image data has bad checksum
2278 4 common/cmd_bootm.c Image data has correct checksum
2279 -4 common/cmd_bootm.c Image is for unsupported architecture
2280 5 common/cmd_bootm.c Architecture check OK
2281 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2282 6 common/cmd_bootm.c Image Type check OK
2283 -6 common/cmd_bootm.c gunzip uncompression error
2284 -7 common/cmd_bootm.c Unimplemented compression type
2285 7 common/cmd_bootm.c Uncompression OK
2286 8 common/cmd_bootm.c No uncompress/copy overwrite error
2287 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2288
2289 9 common/image.c Start initial ramdisk verification
2290 -10 common/image.c Ramdisk header has bad magic number
2291 -11 common/image.c Ramdisk header has bad checksum
2292 10 common/image.c Ramdisk header is OK
2293 -12 common/image.c Ramdisk data has bad checksum
2294 11 common/image.c Ramdisk data has correct checksum
2295 12 common/image.c Ramdisk verification complete, start loading
2296 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2297 13 common/image.c Start multifile image verification
2298 14 common/image.c No initial ramdisk, no multifile, continue.
2299
2300 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2301
2302 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2303 -31 post/post.c POST test failed, detected by post_output_backlog()
2304 -32 post/post.c POST test failed, detected by post_run_single()
2305
2306 34 common/cmd_doc.c before loading a Image from a DOC device
2307 -35 common/cmd_doc.c Bad usage of "doc" command
2308 35 common/cmd_doc.c correct usage of "doc" command
2309 -36 common/cmd_doc.c No boot device
2310 36 common/cmd_doc.c correct boot device
2311 -37 common/cmd_doc.c Unknown Chip ID on boot device
2312 37 common/cmd_doc.c correct chip ID found, device available
2313 -38 common/cmd_doc.c Read Error on boot device
2314 38 common/cmd_doc.c reading Image header from DOC device OK
2315 -39 common/cmd_doc.c Image header has bad magic number
2316 39 common/cmd_doc.c Image header has correct magic number
2317 -40 common/cmd_doc.c Error reading Image from DOC device
2318 40 common/cmd_doc.c Image header has correct magic number
2319 41 common/cmd_ide.c before loading a Image from a IDE device
2320 -42 common/cmd_ide.c Bad usage of "ide" command
2321 42 common/cmd_ide.c correct usage of "ide" command
2322 -43 common/cmd_ide.c No boot device
2323 43 common/cmd_ide.c boot device found
2324 -44 common/cmd_ide.c Device not available
2325 44 common/cmd_ide.c Device available
2326 -45 common/cmd_ide.c wrong partition selected
2327 45 common/cmd_ide.c partition selected
2328 -46 common/cmd_ide.c Unknown partition table
2329 46 common/cmd_ide.c valid partition table found
2330 -47 common/cmd_ide.c Invalid partition type
2331 47 common/cmd_ide.c correct partition type
2332 -48 common/cmd_ide.c Error reading Image Header on boot device
2333 48 common/cmd_ide.c reading Image Header from IDE device OK
2334 -49 common/cmd_ide.c Image header has bad magic number
2335 49 common/cmd_ide.c Image header has correct magic number
2336 -50 common/cmd_ide.c Image header has bad checksum
2337 50 common/cmd_ide.c Image header has correct checksum
2338 -51 common/cmd_ide.c Error reading Image from IDE device
2339 51 common/cmd_ide.c reading Image from IDE device OK
2340 52 common/cmd_nand.c before loading a Image from a NAND device
2341 -53 common/cmd_nand.c Bad usage of "nand" command
2342 53 common/cmd_nand.c correct usage of "nand" command
2343 -54 common/cmd_nand.c No boot device
2344 54 common/cmd_nand.c boot device found
2345 -55 common/cmd_nand.c Unknown Chip ID on boot device
2346 55 common/cmd_nand.c correct chip ID found, device available
2347 -56 common/cmd_nand.c Error reading Image Header on boot device
2348 56 common/cmd_nand.c reading Image Header from NAND device OK
2349 -57 common/cmd_nand.c Image header has bad magic number
2350 57 common/cmd_nand.c Image header has correct magic number
2351 -58 common/cmd_nand.c Error reading Image from NAND device
2352 58 common/cmd_nand.c reading Image from NAND device OK
2353
2354 -60 common/env_common.c Environment has a bad CRC, using default
2355
2356 64 net/eth.c starting with Ethernet configuration.
2357 -64 net/eth.c no Ethernet found.
2358 65 net/eth.c Ethernet found.
2359
2360 -80 common/cmd_net.c usage wrong
2361 80 common/cmd_net.c before calling net_loop()
2362 -81 common/cmd_net.c some error in net_loop() occurred
2363 81 common/cmd_net.c net_loop() back without error
2364 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2365 82 common/cmd_net.c trying automatic boot
2366 83 common/cmd_net.c running "source" command
2367 -83 common/cmd_net.c some error in automatic boot or "source" command
2368 84 common/cmd_net.c end without errors
2369
2370 FIT uImage format:
2371
2372 Arg Where When
2373 100 common/cmd_bootm.c Kernel FIT Image has correct format
2374 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2375 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2376 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2377 102 common/cmd_bootm.c Kernel unit name specified
2378 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2379 103 common/cmd_bootm.c Found configuration node
2380 104 common/cmd_bootm.c Got kernel subimage node offset
2381 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2382 105 common/cmd_bootm.c Kernel subimage hash verification OK
2383 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2384 106 common/cmd_bootm.c Architecture check OK
2385 -106 common/cmd_bootm.c Kernel subimage has wrong type
2386 107 common/cmd_bootm.c Kernel subimage type OK
2387 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2388 108 common/cmd_bootm.c Got kernel subimage data/size
2389 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2390 -109 common/cmd_bootm.c Can't get kernel subimage type
2391 -110 common/cmd_bootm.c Can't get kernel subimage comp
2392 -111 common/cmd_bootm.c Can't get kernel subimage os
2393 -112 common/cmd_bootm.c Can't get kernel subimage load address
2394 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2395
2396 120 common/image.c Start initial ramdisk verification
2397 -120 common/image.c Ramdisk FIT image has incorrect format
2398 121 common/image.c Ramdisk FIT image has correct format
2399 122 common/image.c No ramdisk subimage unit name, using configuration
2400 -122 common/image.c Can't get configuration for ramdisk subimage
2401 123 common/image.c Ramdisk unit name specified
2402 -124 common/image.c Can't get ramdisk subimage node offset
2403 125 common/image.c Got ramdisk subimage node offset
2404 -125 common/image.c Ramdisk subimage hash verification failed
2405 126 common/image.c Ramdisk subimage hash verification OK
2406 -126 common/image.c Ramdisk subimage for unsupported architecture
2407 127 common/image.c Architecture check OK
2408 -127 common/image.c Can't get ramdisk subimage data/size
2409 128 common/image.c Got ramdisk subimage data/size
2410 129 common/image.c Can't get ramdisk load address
2411 -129 common/image.c Got ramdisk load address
2412
2413 -130 common/cmd_doc.c Incorrect FIT image format
2414 131 common/cmd_doc.c FIT image format OK
2415
2416 -140 common/cmd_ide.c Incorrect FIT image format
2417 141 common/cmd_ide.c FIT image format OK
2418
2419 -150 common/cmd_nand.c Incorrect FIT image format
2420 151 common/cmd_nand.c FIT image format OK
2421
2422 - Standalone program support:
2423 CONFIG_STANDALONE_LOAD_ADDR
2424
2425 This option defines a board specific value for the
2426 address where standalone program gets loaded, thus
2427 overwriting the architecture dependent default
2428 settings.
2429
2430 - Frame Buffer Address:
2431 CONFIG_FB_ADDR
2432
2433 Define CONFIG_FB_ADDR if you want to use specific
2434 address for frame buffer. This is typically the case
2435 when using a graphics controller has separate video
2436 memory. U-Boot will then place the frame buffer at
2437 the given address instead of dynamically reserving it
2438 in system RAM by calling lcd_setmem(), which grabs
2439 the memory for the frame buffer depending on the
2440 configured panel size.
2441
2442 Please see board_init_f function.
2443
2444 - Automatic software updates via TFTP server
2445 CONFIG_UPDATE_TFTP
2446 CONFIG_UPDATE_TFTP_CNT_MAX
2447 CONFIG_UPDATE_TFTP_MSEC_MAX
2448
2449 These options enable and control the auto-update feature;
2450 for a more detailed description refer to doc/README.update.
2451
2452 - MTD Support (mtdparts command, UBI support)
2453 CONFIG_MTD_DEVICE
2454
2455 Adds the MTD device infrastructure from the Linux kernel.
2456 Needed for mtdparts command support.
2457
2458 CONFIG_MTD_PARTITIONS
2459
2460 Adds the MTD partitioning infrastructure from the Linux
2461 kernel. Needed for UBI support.
2462
2463 - UBI support
2464 CONFIG_MTD_UBI_WL_THRESHOLD
2465 This parameter defines the maximum difference between the highest
2466 erase counter value and the lowest erase counter value of eraseblocks
2467 of UBI devices. When this threshold is exceeded, UBI starts performing
2468 wear leveling by means of moving data from eraseblock with low erase
2469 counter to eraseblocks with high erase counter.
2470
2471 The default value should be OK for SLC NAND flashes, NOR flashes and
2472 other flashes which have eraseblock life-cycle 100000 or more.
2473 However, in case of MLC NAND flashes which typically have eraseblock
2474 life-cycle less than 10000, the threshold should be lessened (e.g.,
2475 to 128 or 256, although it does not have to be power of 2).
2476
2477 default: 4096
2478
2479 CONFIG_MTD_UBI_BEB_LIMIT
2480 This option specifies the maximum bad physical eraseblocks UBI
2481 expects on the MTD device (per 1024 eraseblocks). If the
2482 underlying flash does not admit of bad eraseblocks (e.g. NOR
2483 flash), this value is ignored.
2484
2485 NAND datasheets often specify the minimum and maximum NVM
2486 (Number of Valid Blocks) for the flashes' endurance lifetime.
2487 The maximum expected bad eraseblocks per 1024 eraseblocks
2488 then can be calculated as "1024 * (1 - MinNVB / MaxNVB)",
2489 which gives 20 for most NANDs (MaxNVB is basically the total
2490 count of eraseblocks on the chip).
2491
2492 To put it differently, if this value is 20, UBI will try to
2493 reserve about 1.9% of physical eraseblocks for bad blocks
2494 handling. And that will be 1.9% of eraseblocks on the entire
2495 NAND chip, not just the MTD partition UBI attaches. This means
2496 that if you have, say, a NAND flash chip admits maximum 40 bad
2497 eraseblocks, and it is split on two MTD partitions of the same
2498 size, UBI will reserve 40 eraseblocks when attaching a
2499 partition.
2500
2501 default: 20
2502
2503 CONFIG_MTD_UBI_FASTMAP
2504 Fastmap is a mechanism which allows attaching an UBI device
2505 in nearly constant time. Instead of scanning the whole MTD device it
2506 only has to locate a checkpoint (called fastmap) on the device.
2507 The on-flash fastmap contains all information needed to attach
2508 the device. Using fastmap makes only sense on large devices where
2509 attaching by scanning takes long. UBI will not automatically install
2510 a fastmap on old images, but you can set the UBI parameter
2511 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT to 1 if you want so. Please note
2512 that fastmap-enabled images are still usable with UBI implementations
2513 without fastmap support. On typical flash devices the whole fastmap
2514 fits into one PEB. UBI will reserve PEBs to hold two fastmaps.
2515
2516 CONFIG_MTD_UBI_FASTMAP_AUTOCONVERT
2517 Set this parameter to enable fastmap automatically on images
2518 without a fastmap.
2519 default: 0
2520
2521 CONFIG_MTD_UBI_FM_DEBUG
2522 Enable UBI fastmap debug
2523 default: 0
2524
2525 - SPL framework
2526 CONFIG_SPL
2527 Enable building of SPL globally.
2528
2529 CONFIG_SPL_LDSCRIPT
2530 LDSCRIPT for linking the SPL binary.
2531
2532 CONFIG_SPL_MAX_FOOTPRINT
2533 Maximum size in memory allocated to the SPL, BSS included.
2534 When defined, the linker checks that the actual memory
2535 used by SPL from _start to __bss_end does not exceed it.
2536 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2537 must not be both defined at the same time.
2538
2539 CONFIG_SPL_MAX_SIZE
2540 Maximum size of the SPL image (text, data, rodata, and
2541 linker lists sections), BSS excluded.
2542 When defined, the linker checks that the actual size does
2543 not exceed it.
2544
2545 CONFIG_SPL_TEXT_BASE
2546 TEXT_BASE for linking the SPL binary.
2547
2548 CONFIG_SPL_RELOC_TEXT_BASE
2549 Address to relocate to. If unspecified, this is equal to
2550 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
2551
2552 CONFIG_SPL_BSS_START_ADDR
2553 Link address for the BSS within the SPL binary.
2554
2555 CONFIG_SPL_BSS_MAX_SIZE
2556 Maximum size in memory allocated to the SPL BSS.
2557 When defined, the linker checks that the actual memory used
2558 by SPL from __bss_start to __bss_end does not exceed it.
2559 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
2560 must not be both defined at the same time.
2561
2562 CONFIG_SPL_STACK
2563 Adress of the start of the stack SPL will use
2564
2565 CONFIG_SPL_PANIC_ON_RAW_IMAGE
2566 When defined, SPL will panic() if the image it has
2567 loaded does not have a signature.
2568 Defining this is useful when code which loads images
2569 in SPL cannot guarantee that absolutely all read errors
2570 will be caught.
2571 An example is the LPC32XX MLC NAND driver, which will
2572 consider that a completely unreadable NAND block is bad,
2573 and thus should be skipped silently.
2574
2575 CONFIG_SPL_RELOC_STACK
2576 Adress of the start of the stack SPL will use after
2577 relocation. If unspecified, this is equal to
2578 CONFIG_SPL_STACK.
2579
2580 CONFIG_SYS_SPL_MALLOC_START
2581 Starting address of the malloc pool used in SPL.
2582 When this option is set the full malloc is used in SPL and
2583 it is set up by spl_init() and before that, the simple malloc()
2584 can be used if CONFIG_SYS_MALLOC_F is defined.
2585
2586 CONFIG_SYS_SPL_MALLOC_SIZE
2587 The size of the malloc pool used in SPL.
2588
2589 CONFIG_SPL_OS_BOOT
2590 Enable booting directly to an OS from SPL.
2591 See also: doc/README.falcon
2592
2593 CONFIG_SPL_DISPLAY_PRINT
2594 For ARM, enable an optional function to print more information
2595 about the running system.
2596
2597 CONFIG_SPL_INIT_MINIMAL
2598 Arch init code should be built for a very small image
2599
2600 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION
2601 Partition on the MMC to load U-Boot from when the MMC is being
2602 used in raw mode
2603
2604 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
2605 Sector to load kernel uImage from when MMC is being
2606 used in raw mode (for Falcon mode)
2607
2608 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
2609 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
2610 Sector and number of sectors to load kernel argument
2611 parameters from when MMC is being used in raw mode
2612 (for falcon mode)
2613
2614 CONFIG_SYS_MMCSD_FS_BOOT_PARTITION
2615 Partition on the MMC to load U-Boot from when the MMC is being
2616 used in fs mode
2617
2618 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
2619 Filename to read to load U-Boot when reading from filesystem
2620
2621 CONFIG_SPL_FS_LOAD_KERNEL_NAME
2622 Filename to read to load kernel uImage when reading
2623 from filesystem (for Falcon mode)
2624
2625 CONFIG_SPL_FS_LOAD_ARGS_NAME
2626 Filename to read to load kernel argument parameters
2627 when reading from filesystem (for Falcon mode)
2628
2629 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
2630 Set this for NAND SPL on PPC mpc83xx targets, so that
2631 start.S waits for the rest of the SPL to load before
2632 continuing (the hardware starts execution after just
2633 loading the first page rather than the full 4K).
2634
2635 CONFIG_SPL_SKIP_RELOCATE
2636 Avoid SPL relocation
2637
2638 CONFIG_SPL_NAND_BASE
2639 Include nand_base.c in the SPL. Requires
2640 CONFIG_SPL_NAND_DRIVERS.
2641
2642 CONFIG_SPL_NAND_DRIVERS
2643 SPL uses normal NAND drivers, not minimal drivers.
2644
2645 CONFIG_SPL_NAND_IDENT
2646 SPL uses the chip ID list to identify the NAND flash.
2647 Requires CONFIG_SPL_NAND_BASE.
2648
2649 CONFIG_SPL_NAND_ECC
2650 Include standard software ECC in the SPL
2651
2652 CONFIG_SPL_NAND_SIMPLE
2653 Support for NAND boot using simple NAND drivers that
2654 expose the cmd_ctrl() interface.
2655
2656 CONFIG_SPL_UBI
2657 Support for a lightweight UBI (fastmap) scanner and
2658 loader
2659
2660 CONFIG_SPL_NAND_RAW_ONLY
2661 Support to boot only raw u-boot.bin images. Use this only
2662 if you need to save space.
2663
2664 CONFIG_SPL_COMMON_INIT_DDR
2665 Set for common ddr init with serial presence detect in
2666 SPL binary.
2667
2668 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
2669 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
2670 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
2671 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
2672 CONFIG_SYS_NAND_ECCBYTES
2673 Defines the size and behavior of the NAND that SPL uses
2674 to read U-Boot
2675
2676 CONFIG_SPL_NAND_BOOT
2677 Add support NAND boot
2678
2679 CONFIG_SYS_NAND_U_BOOT_OFFS
2680 Location in NAND to read U-Boot from
2681
2682 CONFIG_SYS_NAND_U_BOOT_DST
2683 Location in memory to load U-Boot to
2684
2685 CONFIG_SYS_NAND_U_BOOT_SIZE
2686 Size of image to load
2687
2688 CONFIG_SYS_NAND_U_BOOT_START
2689 Entry point in loaded image to jump to
2690
2691 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
2692 Define this if you need to first read the OOB and then the
2693 data. This is used, for example, on davinci platforms.
2694
2695 CONFIG_SPL_RAM_DEVICE
2696 Support for running image already present in ram, in SPL binary
2697
2698 CONFIG_SPL_PAD_TO
2699 Image offset to which the SPL should be padded before appending
2700 the SPL payload. By default, this is defined as
2701 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2702 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2703 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
2704
2705 CONFIG_SPL_TARGET
2706 Final target image containing SPL and payload. Some SPLs
2707 use an arch-specific makefile fragment instead, for
2708 example if more than one image needs to be produced.
2709
2710 CONFIG_SPL_FIT_PRINT
2711 Printing information about a FIT image adds quite a bit of
2712 code to SPL. So this is normally disabled in SPL. Use this
2713 option to re-enable it. This will affect the output of the
2714 bootm command when booting a FIT image.
2715
2716 - TPL framework
2717 CONFIG_TPL
2718 Enable building of TPL globally.
2719
2720 CONFIG_TPL_PAD_TO
2721 Image offset to which the TPL should be padded before appending
2722 the TPL payload. By default, this is defined as
2723 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
2724 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
2725 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
2726
2727 - Interrupt support (PPC):
2728
2729 There are common interrupt_init() and timer_interrupt()
2730 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2731 for CPU specific initialization. interrupt_init_cpu()
2732 should set decrementer_count to appropriate value. If
2733 CPU resets decrementer automatically after interrupt
2734 (ppc4xx) it should set decrementer_count to zero.
2735 timer_interrupt() calls timer_interrupt_cpu() for CPU
2736 specific handling. If board has watchdog / status_led
2737 / other_activity_monitor it works automatically from
2738 general timer_interrupt().
2739
2740
2741 Board initialization settings:
2742 ------------------------------
2743
2744 During Initialization u-boot calls a number of board specific functions
2745 to allow the preparation of board specific prerequisites, e.g. pin setup
2746 before drivers are initialized. To enable these callbacks the
2747 following configuration macros have to be defined. Currently this is
2748 architecture specific, so please check arch/your_architecture/lib/board.c
2749 typically in board_init_f() and board_init_r().
2750
2751 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
2752 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
2753 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
2754 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
2755
2756 Configuration Settings:
2757 -----------------------
2758
2759 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
2760 Optionally it can be defined to support 64-bit memory commands.
2761
2762 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2763 undefine this when you're short of memory.
2764
2765 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2766 width of the commands listed in the 'help' command output.
2767
2768 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2769 prompt for user input.
2770
2771 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2772
2773 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2774
2775 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2776
2777 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2778 the application (usually a Linux kernel) when it is
2779 booted
2780
2781 - CONFIG_SYS_BAUDRATE_TABLE:
2782 List of legal baudrate settings for this board.
2783
2784 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2785 Begin and End addresses of the area used by the
2786 simple memory test.
2787
2788 - CONFIG_SYS_MEMTEST_SCRATCH:
2789 Scratch address used by the alternate memory test
2790 You only need to set this if address zero isn't writeable
2791
2792 - CONFIG_SYS_MEM_RESERVE_SECURE
2793 Only implemented for ARMv8 for now.
2794 If defined, the size of CONFIG_SYS_MEM_RESERVE_SECURE memory
2795 is substracted from total RAM and won't be reported to OS.
2796 This memory can be used as secure memory. A variable
2797 gd->arch.secure_ram is used to track the location. In systems
2798 the RAM base is not zero, or RAM is divided into banks,
2799 this variable needs to be recalcuated to get the address.
2800
2801 - CONFIG_SYS_MEM_TOP_HIDE:
2802 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2803 this specified memory area will get subtracted from the top
2804 (end) of RAM and won't get "touched" at all by U-Boot. By
2805 fixing up gd->ram_size the Linux kernel should gets passed
2806 the now "corrected" memory size and won't touch it either.
2807 This should work for arch/ppc and arch/powerpc. Only Linux
2808 board ports in arch/powerpc with bootwrapper support that
2809 recalculate the memory size from the SDRAM controller setup
2810 will have to get fixed in Linux additionally.
2811
2812 This option can be used as a workaround for the 440EPx/GRx
2813 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2814 be touched.
2815
2816 WARNING: Please make sure that this value is a multiple of
2817 the Linux page size (normally 4k). If this is not the case,
2818 then the end address of the Linux memory will be located at a
2819 non page size aligned address and this could cause major
2820 problems.
2821
2822 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2823 Enable temporary baudrate change while serial download
2824
2825 - CONFIG_SYS_SDRAM_BASE:
2826 Physical start address of SDRAM. _Must_ be 0 here.
2827
2828 - CONFIG_SYS_FLASH_BASE:
2829 Physical start address of Flash memory.
2830
2831 - CONFIG_SYS_MONITOR_BASE:
2832 Physical start address of boot monitor code (set by
2833 make config files to be same as the text base address
2834 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2835 CONFIG_SYS_FLASH_BASE when booting from flash.
2836
2837 - CONFIG_SYS_MONITOR_LEN:
2838 Size of memory reserved for monitor code, used to
2839 determine _at_compile_time_ (!) if the environment is
2840 embedded within the U-Boot image, or in a separate
2841 flash sector.
2842
2843 - CONFIG_SYS_MALLOC_LEN:
2844 Size of DRAM reserved for malloc() use.
2845
2846 - CONFIG_SYS_MALLOC_F_LEN
2847 Size of the malloc() pool for use before relocation. If
2848 this is defined, then a very simple malloc() implementation
2849 will become available before relocation. The address is just
2850 below the global data, and the stack is moved down to make
2851 space.
2852
2853 This feature allocates regions with increasing addresses
2854 within the region. calloc() is supported, but realloc()
2855 is not available. free() is supported but does nothing.
2856 The memory will be freed (or in fact just forgotten) when
2857 U-Boot relocates itself.
2858
2859 - CONFIG_SYS_MALLOC_SIMPLE
2860 Provides a simple and small malloc() and calloc() for those
2861 boards which do not use the full malloc in SPL (which is
2862 enabled with CONFIG_SYS_SPL_MALLOC_START).
2863
2864 - CONFIG_SYS_NONCACHED_MEMORY:
2865 Size of non-cached memory area. This area of memory will be
2866 typically located right below the malloc() area and mapped
2867 uncached in the MMU. This is useful for drivers that would
2868 otherwise require a lot of explicit cache maintenance. For
2869 some drivers it's also impossible to properly maintain the
2870 cache. For example if the regions that need to be flushed
2871 are not a multiple of the cache-line size, *and* padding
2872 cannot be allocated between the regions to align them (i.e.
2873 if the HW requires a contiguous array of regions, and the
2874 size of each region is not cache-aligned), then a flush of
2875 one region may result in overwriting data that hardware has
2876 written to another region in the same cache-line. This can
2877 happen for example in network drivers where descriptors for
2878 buffers are typically smaller than the CPU cache-line (e.g.
2879 16 bytes vs. 32 or 64 bytes).
2880
2881 Non-cached memory is only supported on 32-bit ARM at present.
2882
2883 - CONFIG_SYS_BOOTM_LEN:
2884 Normally compressed uImages are limited to an
2885 uncompressed size of 8 MBytes. If this is not enough,
2886 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2887 to adjust this setting to your needs.
2888
2889 - CONFIG_SYS_BOOTMAPSZ:
2890 Maximum size of memory mapped by the startup code of
2891 the Linux kernel; all data that must be processed by
2892 the Linux kernel (bd_info, boot arguments, FDT blob if
2893 used) must be put below this limit, unless "bootm_low"
2894 environment variable is defined and non-zero. In such case
2895 all data for the Linux kernel must be between "bootm_low"
2896 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2897 variable "bootm_mapsize" will override the value of
2898 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2899 then the value in "bootm_size" will be used instead.
2900
2901 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2902 Enable initrd_high functionality. If defined then the
2903 initrd_high feature is enabled and the bootm ramdisk subcommand
2904 is enabled.
2905
2906 - CONFIG_SYS_BOOT_GET_CMDLINE:
2907 Enables allocating and saving kernel cmdline in space between
2908 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2909
2910 - CONFIG_SYS_BOOT_GET_KBD:
2911 Enables allocating and saving a kernel copy of the bd_info in
2912 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2913
2914 - CONFIG_SYS_MAX_FLASH_BANKS:
2915 Max number of Flash memory banks
2916
2917 - CONFIG_SYS_MAX_FLASH_SECT:
2918 Max number of sectors on a Flash chip
2919
2920 - CONFIG_SYS_FLASH_ERASE_TOUT:
2921 Timeout for Flash erase operations (in ms)
2922
2923 - CONFIG_SYS_FLASH_WRITE_TOUT:
2924 Timeout for Flash write operations (in ms)
2925
2926 - CONFIG_SYS_FLASH_LOCK_TOUT
2927 Timeout for Flash set sector lock bit operation (in ms)
2928
2929 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2930 Timeout for Flash clear lock bits operation (in ms)
2931
2932 - CONFIG_SYS_FLASH_PROTECTION
2933 If defined, hardware flash sectors protection is used
2934 instead of U-Boot software protection.
2935
2936 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2937
2938 Enable TFTP transfers directly to flash memory;
2939 without this option such a download has to be
2940 performed in two steps: (1) download to RAM, and (2)
2941 copy from RAM to flash.
2942
2943 The two-step approach is usually more reliable, since
2944 you can check if the download worked before you erase
2945 the flash, but in some situations (when system RAM is
2946 too limited to allow for a temporary copy of the
2947 downloaded image) this option may be very useful.
2948
2949 - CONFIG_SYS_FLASH_CFI:
2950 Define if the flash driver uses extra elements in the
2951 common flash structure for storing flash geometry.
2952
2953 - CONFIG_FLASH_CFI_DRIVER
2954 This option also enables the building of the cfi_flash driver
2955 in the drivers directory
2956
2957 - CONFIG_FLASH_CFI_MTD
2958 This option enables the building of the cfi_mtd driver
2959 in the drivers directory. The driver exports CFI flash
2960 to the MTD layer.
2961
2962 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2963 Use buffered writes to flash.
2964
2965 - CONFIG_FLASH_SPANSION_S29WS_N
2966 s29ws-n MirrorBit flash has non-standard addresses for buffered
2967 write commands.
2968
2969 - CONFIG_SYS_FLASH_QUIET_TEST
2970 If this option is defined, the common CFI flash doesn't
2971 print it's warning upon not recognized FLASH banks. This
2972 is useful, if some of the configured banks are only
2973 optionally available.
2974
2975 - CONFIG_FLASH_SHOW_PROGRESS
2976 If defined (must be an integer), print out countdown
2977 digits and dots. Recommended value: 45 (9..1) for 80
2978 column displays, 15 (3..1) for 40 column displays.
2979
2980 - CONFIG_FLASH_VERIFY
2981 If defined, the content of the flash (destination) is compared
2982 against the source after the write operation. An error message
2983 will be printed when the contents are not identical.
2984 Please note that this option is useless in nearly all cases,
2985 since such flash programming errors usually are detected earlier
2986 while unprotecting/erasing/programming. Please only enable
2987 this option if you really know what you are doing.
2988
2989 - CONFIG_SYS_RX_ETH_BUFFER:
2990 Defines the number of Ethernet receive buffers. On some
2991 Ethernet controllers it is recommended to set this value
2992 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2993 buffers can be full shortly after enabling the interface
2994 on high Ethernet traffic.
2995 Defaults to 4 if not defined.
2996
2997 - CONFIG_ENV_MAX_ENTRIES
2998
2999 Maximum number of entries in the hash table that is used
3000 internally to store the environment settings. The default
3001 setting is supposed to be generous and should work in most
3002 cases. This setting can be used to tune behaviour; see
3003 lib/hashtable.c for details.
3004
3005 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3006 - CONFIG_ENV_FLAGS_LIST_STATIC
3007 Enable validation of the values given to environment variables when
3008 calling env set. Variables can be restricted to only decimal,
3009 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3010 the variables can also be restricted to IP address or MAC address.
3011
3012 The format of the list is:
3013 type_attribute = [s|d|x|b|i|m]
3014 access_attribute = [a|r|o|c]
3015 attributes = type_attribute[access_attribute]
3016 entry = variable_name[:attributes]
3017 list = entry[,list]
3018
3019 The type attributes are:
3020 s - String (default)
3021 d - Decimal
3022 x - Hexadecimal
3023 b - Boolean ([1yYtT|0nNfF])
3024 i - IP address
3025 m - MAC address
3026
3027 The access attributes are:
3028 a - Any (default)
3029 r - Read-only
3030 o - Write-once
3031 c - Change-default
3032
3033 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3034 Define this to a list (string) to define the ".flags"
3035 environment variable in the default or embedded environment.
3036
3037 - CONFIG_ENV_FLAGS_LIST_STATIC
3038 Define this to a list (string) to define validation that
3039 should be done if an entry is not found in the ".flags"
3040 environment variable. To override a setting in the static
3041 list, simply add an entry for the same variable name to the
3042 ".flags" variable.
3043
3044 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3045 regular expression. This allows multiple variables to define the same
3046 flags without explicitly listing them for each variable.
3047
3048 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3049 If defined, don't allow the -f switch to env set override variable
3050 access flags.
3051
3052 - CONFIG_USE_STDINT
3053 If stdint.h is available with your toolchain you can define this
3054 option to enable it. You can provide option 'USE_STDINT=1' when
3055 building U-Boot to enable this.
3056
3057 The following definitions that deal with the placement and management
3058 of environment data (variable area); in general, we support the
3059 following configurations:
3060
3061 - CONFIG_BUILD_ENVCRC:
3062
3063 Builds up envcrc with the target environment so that external utils
3064 may easily extract it and embed it in final U-Boot images.
3065
3066 BE CAREFUL! The first access to the environment happens quite early
3067 in U-Boot initialization (when we try to get the setting of for the
3068 console baudrate). You *MUST* have mapped your NVRAM area then, or
3069 U-Boot will hang.
3070
3071 Please note that even with NVRAM we still use a copy of the
3072 environment in RAM: we could work on NVRAM directly, but we want to
3073 keep settings there always unmodified except somebody uses "saveenv"
3074 to save the current settings.
3075
3076 BE CAREFUL! For some special cases, the local device can not use
3077 "saveenv" command. For example, the local device will get the
3078 environment stored in a remote NOR flash by SRIO or PCIE link,
3079 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3080
3081 - CONFIG_NAND_ENV_DST
3082
3083 Defines address in RAM to which the nand_spl code should copy the
3084 environment. If redundant environment is used, it will be copied to
3085 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3086
3087 Please note that the environment is read-only until the monitor
3088 has been relocated to RAM and a RAM copy of the environment has been
3089 created; also, when using EEPROM you will have to use env_get_f()
3090 until then to read environment variables.
3091
3092 The environment is protected by a CRC32 checksum. Before the monitor
3093 is relocated into RAM, as a result of a bad CRC you will be working
3094 with the compiled-in default environment - *silently*!!! [This is
3095 necessary, because the first environment variable we need is the
3096 "baudrate" setting for the console - if we have a bad CRC, we don't
3097 have any device yet where we could complain.]
3098
3099 Note: once the monitor has been relocated, then it will complain if
3100 the default environment is used; a new CRC is computed as soon as you
3101 use the "saveenv" command to store a valid environment.
3102
3103 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
3104 Echo the inverted Ethernet link state to the fault LED.
3105
3106 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
3107 also needs to be defined.
3108
3109 - CONFIG_SYS_FAULT_MII_ADDR:
3110 MII address of the PHY to check for the Ethernet link state.
3111
3112 - CONFIG_NS16550_MIN_FUNCTIONS:
3113 Define this if you desire to only have use of the NS16550_init
3114 and NS16550_putc functions for the serial driver located at
3115 drivers/serial/ns16550.c. This option is useful for saving
3116 space for already greatly restricted images, including but not
3117 limited to NAND_SPL configurations.
3118
3119 - CONFIG_DISPLAY_BOARDINFO
3120 Display information about the board that U-Boot is running on
3121 when U-Boot starts up. The board function checkboard() is called
3122 to do this.
3123
3124 - CONFIG_DISPLAY_BOARDINFO_LATE
3125 Similar to the previous option, but display this information
3126 later, once stdio is running and output goes to the LCD, if
3127 present.
3128
3129 - CONFIG_BOARD_SIZE_LIMIT:
3130 Maximum size of the U-Boot image. When defined, the
3131 build system checks that the actual size does not
3132 exceed it.
3133
3134 Low Level (hardware related) configuration options:
3135 ---------------------------------------------------
3136
3137 - CONFIG_SYS_CACHELINE_SIZE:
3138 Cache Line Size of the CPU.
3139
3140 - CONFIG_SYS_CCSRBAR_DEFAULT:
3141 Default (power-on reset) physical address of CCSR on Freescale
3142 PowerPC SOCs.
3143
3144 - CONFIG_SYS_CCSRBAR:
3145 Virtual address of CCSR. On a 32-bit build, this is typically
3146 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
3147
3148 - CONFIG_SYS_CCSRBAR_PHYS:
3149 Physical address of CCSR. CCSR can be relocated to a new
3150 physical address, if desired. In this case, this macro should
3151 be set to that address. Otherwise, it should be set to the
3152 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
3153 is typically relocated on 36-bit builds. It is recommended
3154 that this macro be defined via the _HIGH and _LOW macros:
3155
3156 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
3157 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
3158
3159 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
3160 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
3161 either 0 (32-bit build) or 0xF (36-bit build). This macro is
3162 used in assembly code, so it must not contain typecasts or
3163 integer size suffixes (e.g. "ULL").
3164
3165 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
3166 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
3167 used in assembly code, so it must not contain typecasts or
3168 integer size suffixes (e.g. "ULL").
3169
3170 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
3171 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
3172 forced to a value that ensures that CCSR is not relocated.
3173
3174 - Floppy Disk Support:
3175 CONFIG_SYS_FDC_DRIVE_NUMBER
3176
3177 the default drive number (default value 0)
3178
3179 CONFIG_SYS_ISA_IO_STRIDE
3180
3181 defines the spacing between FDC chipset registers
3182 (default value 1)
3183
3184 CONFIG_SYS_ISA_IO_OFFSET
3185
3186 defines the offset of register from address. It
3187 depends on which part of the data bus is connected to
3188 the FDC chipset. (default value 0)
3189
3190 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
3191 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
3192 default value.
3193
3194 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
3195 fdc_hw_init() is called at the beginning of the FDC
3196 setup. fdc_hw_init() must be provided by the board
3197 source code. It is used to make hardware-dependent
3198 initializations.
3199
3200 - CONFIG_IDE_AHB:
3201 Most IDE controllers were designed to be connected with PCI
3202 interface. Only few of them were designed for AHB interface.
3203 When software is doing ATA command and data transfer to
3204 IDE devices through IDE-AHB controller, some additional
3205 registers accessing to these kind of IDE-AHB controller
3206 is required.
3207
3208 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
3209 DO NOT CHANGE unless you know exactly what you're
3210 doing! (11-4) [MPC8xx systems only]
3211
3212 - CONFIG_SYS_INIT_RAM_ADDR:
3213
3214 Start address of memory area that can be used for
3215 initial data and stack; please note that this must be
3216 writable memory that is working WITHOUT special
3217 initialization, i. e. you CANNOT use normal RAM which
3218 will become available only after programming the
3219 memory controller and running certain initialization
3220 sequences.
3221
3222 U-Boot uses the following memory types:
3223 - MPC8xx: IMMR (internal memory of the CPU)
3224
3225 - CONFIG_SYS_GBL_DATA_OFFSET:
3226
3227 Offset of the initial data structure in the memory
3228 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
3229 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
3230 data is located at the end of the available space
3231 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
3232 GENERATED_GBL_DATA_SIZE), and the initial stack is just
3233 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3234 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3235
3236 Note:
3237 On the MPC824X (or other systems that use the data
3238 cache for initial memory) the address chosen for
3239 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3240 point to an otherwise UNUSED address space between
3241 the top of RAM and the start of the PCI space.
3242
3243 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3244
3245 - CONFIG_SYS_OR_TIMING_SDRAM:
3246 SDRAM timing
3247
3248 - CONFIG_SYS_MAMR_PTA:
3249 periodic timer for refresh
3250
3251 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3252 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3253 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3254 CONFIG_SYS_BR1_PRELIM:
3255 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3256
3257 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3258 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3259 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3260 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3261
3262 - CONFIG_PCI_ENUM_ONLY
3263 Only scan through and get the devices on the buses.
3264 Don't do any setup work, presumably because someone or
3265 something has already done it, and we don't need to do it
3266 a second time. Useful for platforms that are pre-booted
3267 by coreboot or similar.
3268
3269 - CONFIG_PCI_INDIRECT_BRIDGE:
3270 Enable support for indirect PCI bridges.
3271
3272 - CONFIG_SYS_SRIO:
3273 Chip has SRIO or not
3274
3275 - CONFIG_SRIO1:
3276 Board has SRIO 1 port available
3277
3278 - CONFIG_SRIO2:
3279 Board has SRIO 2 port available
3280
3281 - CONFIG_SRIO_PCIE_BOOT_MASTER
3282 Board can support master function for Boot from SRIO and PCIE
3283
3284 - CONFIG_SYS_SRIOn_MEM_VIRT:
3285 Virtual Address of SRIO port 'n' memory region
3286
3287 - CONFIG_SYS_SRIOn_MEM_PHYS:
3288 Physical Address of SRIO port 'n' memory region
3289
3290 - CONFIG_SYS_SRIOn_MEM_SIZE:
3291 Size of SRIO port 'n' memory region
3292
3293 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
3294 Defined to tell the NAND controller that the NAND chip is using
3295 a 16 bit bus.
3296 Not all NAND drivers use this symbol.
3297 Example of drivers that use it:
3298 - drivers/mtd/nand/ndfc.c
3299 - drivers/mtd/nand/mxc_nand.c
3300
3301 - CONFIG_SYS_NDFC_EBC0_CFG
3302 Sets the EBC0_CFG register for the NDFC. If not defined
3303 a default value will be used.
3304
3305 - CONFIG_SPD_EEPROM
3306 Get DDR timing information from an I2C EEPROM. Common
3307 with pluggable memory modules such as SODIMMs
3308
3309 SPD_EEPROM_ADDRESS
3310 I2C address of the SPD EEPROM
3311
3312 - CONFIG_SYS_SPD_BUS_NUM
3313 If SPD EEPROM is on an I2C bus other than the first
3314 one, specify here. Note that the value must resolve
3315 to something your driver can deal with.
3316
3317 - CONFIG_SYS_DDR_RAW_TIMING
3318 Get DDR timing information from other than SPD. Common with
3319 soldered DDR chips onboard without SPD. DDR raw timing
3320 parameters are extracted from datasheet and hard-coded into
3321 header files or board specific files.
3322
3323 - CONFIG_FSL_DDR_INTERACTIVE
3324 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3325
3326 - CONFIG_FSL_DDR_SYNC_REFRESH
3327 Enable sync of refresh for multiple controllers.
3328
3329 - CONFIG_FSL_DDR_BIST
3330 Enable built-in memory test for Freescale DDR controllers.
3331
3332 - CONFIG_SYS_83XX_DDR_USES_CS0
3333 Only for 83xx systems. If specified, then DDR should
3334 be configured using CS0 and CS1 instead of CS2 and CS3.
3335
3336 - CONFIG_RMII
3337 Enable RMII mode for all FECs.
3338 Note that this is a global option, we can't
3339 have one FEC in standard MII mode and another in RMII mode.
3340
3341 - CONFIG_CRC32_VERIFY
3342 Add a verify option to the crc32 command.
3343 The syntax is:
3344
3345 => crc32 -v <address> <count> <crc32>
3346
3347 Where address/count indicate a memory area
3348 and crc32 is the correct crc32 which the
3349 area should have.
3350
3351 - CONFIG_LOOPW
3352 Add the "loopw" memory command. This only takes effect if
3353 the memory commands are activated globally (CONFIG_CMD_MEMORY).
3354
3355 - CONFIG_MX_CYCLIC
3356 Add the "mdc" and "mwc" memory commands. These are cyclic
3357 "md/mw" commands.
3358 Examples:
3359
3360 => mdc.b 10 4 500
3361 This command will print 4 bytes (10,11,12,13) each 500 ms.
3362
3363 => mwc.l 100 12345678 10
3364 This command will write 12345678 to address 100 all 10 ms.
3365
3366 This only takes effect if the memory commands are activated
3367 globally (CONFIG_CMD_MEMORY).
3368
3369 - CONFIG_SKIP_LOWLEVEL_INIT
3370 [ARM, NDS32, MIPS, RISC-V only] If this variable is defined, then certain
3371 low level initializations (like setting up the memory
3372 controller) are omitted and/or U-Boot does not
3373 relocate itself into RAM.
3374
3375 Normally this variable MUST NOT be defined. The only
3376 exception is when U-Boot is loaded (to RAM) by some
3377 other boot loader or by a debugger which performs
3378 these initializations itself.
3379
3380 - CONFIG_SKIP_LOWLEVEL_INIT_ONLY
3381 [ARM926EJ-S only] This allows just the call to lowlevel_init()
3382 to be skipped. The normal CP15 init (such as enabling the
3383 instruction cache) is still performed.
3384
3385 - CONFIG_SPL_BUILD
3386 Modifies the behaviour of start.S when compiling a loader
3387 that is executed before the actual U-Boot. E.g. when
3388 compiling a NAND SPL.
3389
3390 - CONFIG_TPL_BUILD
3391 Modifies the behaviour of start.S when compiling a loader
3392 that is executed after the SPL and before the actual U-Boot.
3393 It is loaded by the SPL.
3394
3395 - CONFIG_SYS_MPC85XX_NO_RESETVEC
3396 Only for 85xx systems. If this variable is specified, the section
3397 .resetvec is not kept and the section .bootpg is placed in the
3398 previous 4k of the .text section.
3399
3400 - CONFIG_ARCH_MAP_SYSMEM
3401 Generally U-Boot (and in particular the md command) uses
3402 effective address. It is therefore not necessary to regard
3403 U-Boot address as virtual addresses that need to be translated
3404 to physical addresses. However, sandbox requires this, since
3405 it maintains its own little RAM buffer which contains all
3406 addressable memory. This option causes some memory accesses
3407 to be mapped through map_sysmem() / unmap_sysmem().
3408
3409 - CONFIG_X86_RESET_VECTOR
3410 If defined, the x86 reset vector code is included. This is not
3411 needed when U-Boot is running from Coreboot.
3412
3413 - CONFIG_SYS_NAND_NO_SUBPAGE_WRITE
3414 Option to disable subpage write in NAND driver
3415 driver that uses this:
3416 drivers/mtd/nand/davinci_nand.c
3417
3418 Freescale QE/FMAN Firmware Support:
3419 -----------------------------------
3420
3421 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
3422 loading of "firmware", which is encoded in the QE firmware binary format.
3423 This firmware often needs to be loaded during U-Boot booting, so macros
3424 are used to identify the storage device (NOR flash, SPI, etc) and the address
3425 within that device.
3426
3427 - CONFIG_SYS_FMAN_FW_ADDR
3428 The address in the storage device where the FMAN microcode is located. The
3429 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3430 is also specified.
3431
3432 - CONFIG_SYS_QE_FW_ADDR
3433 The address in the storage device where the QE microcode is located. The
3434 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
3435 is also specified.
3436
3437 - CONFIG_SYS_QE_FMAN_FW_LENGTH
3438 The maximum possible size of the firmware. The firmware binary format
3439 has a field that specifies the actual size of the firmware, but it
3440 might not be possible to read any part of the firmware unless some
3441 local storage is allocated to hold the entire firmware first.
3442
3443 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
3444 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
3445 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
3446 virtual address in NOR flash.
3447
3448 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
3449 Specifies that QE/FMAN firmware is located in NAND flash.
3450 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
3451
3452 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
3453 Specifies that QE/FMAN firmware is located on the primary SD/MMC
3454 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
3455
3456 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
3457 Specifies that QE/FMAN firmware is located in the remote (master)
3458 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
3459 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
3460 window->master inbound window->master LAW->the ucode address in
3461 master's memory space.
3462
3463 Freescale Layerscape Management Complex Firmware Support:
3464 ---------------------------------------------------------
3465 The Freescale Layerscape Management Complex (MC) supports the loading of
3466 "firmware".
3467 This firmware often needs to be loaded during U-Boot booting, so macros
3468 are used to identify the storage device (NOR flash, SPI, etc) and the address
3469 within that device.
3470
3471 - CONFIG_FSL_MC_ENET
3472 Enable the MC driver for Layerscape SoCs.
3473
3474 Freescale Layerscape Debug Server Support:
3475 -------------------------------------------
3476 The Freescale Layerscape Debug Server Support supports the loading of
3477 "Debug Server firmware" and triggering SP boot-rom.
3478 This firmware often needs to be loaded during U-Boot booting.
3479
3480 - CONFIG_SYS_MC_RSV_MEM_ALIGN
3481 Define alignment of reserved memory MC requires
3482
3483 Reproducible builds
3484 -------------------
3485
3486 In order to achieve reproducible builds, timestamps used in the U-Boot build
3487 process have to be set to a fixed value.
3488
3489 This is done using the SOURCE_DATE_EPOCH environment variable.
3490 SOURCE_DATE_EPOCH is to be set on the build host's shell, not as a configuration
3491 option for U-Boot or an environment variable in U-Boot.
3492
3493 SOURCE_DATE_EPOCH should be set to a number of seconds since the epoch, in UTC.
3494
3495 Building the Software:
3496 ======================
3497
3498 Building U-Boot has been tested in several native build environments
3499 and in many different cross environments. Of course we cannot support
3500 all possibly existing versions of cross development tools in all
3501 (potentially obsolete) versions. In case of tool chain problems we
3502 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3503 which is extensively used to build and test U-Boot.
3504
3505 If you are not using a native environment, it is assumed that you
3506 have GNU cross compiling tools available in your path. In this case,
3507 you must set the environment variable CROSS_COMPILE in your shell.
3508 Note that no changes to the Makefile or any other source files are
3509 necessary. For example using the ELDK on a 4xx CPU, please enter:
3510
3511 $ CROSS_COMPILE=ppc_4xx-
3512 $ export CROSS_COMPILE
3513
3514 Note: If you wish to generate Windows versions of the utilities in
3515 the tools directory you can use the MinGW toolchain
3516 (http://www.mingw.org). Set your HOST tools to the MinGW
3517 toolchain and execute 'make tools'. For example:
3518
3519 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3520
3521 Binaries such as tools/mkimage.exe will be created which can
3522 be executed on computers running Windows.
3523
3524 U-Boot is intended to be simple to build. After installing the
3525 sources you must configure U-Boot for one specific board type. This
3526 is done by typing:
3527
3528 make NAME_defconfig
3529
3530 where "NAME_defconfig" is the name of one of the existing configu-
3531 rations; see boards.cfg for supported names.
3532
3533 Note: for some board special configuration names may exist; check if
3534 additional information is available from the board vendor; for
3535 instance, the TQM823L systems are available without (standard)
3536 or with LCD support. You can select such additional "features"
3537 when choosing the configuration, i. e.
3538
3539 make TQM823L_defconfig
3540 - will configure for a plain TQM823L, i. e. no LCD support
3541
3542 make TQM823L_LCD_defconfig
3543 - will configure for a TQM823L with U-Boot console on LCD
3544
3545 etc.
3546
3547
3548 Finally, type "make all", and you should get some working U-Boot
3549 images ready for download to / installation on your system:
3550
3551 - "u-boot.bin" is a raw binary image
3552 - "u-boot" is an image in ELF binary format
3553 - "u-boot.srec" is in Motorola S-Record format
3554
3555 By default the build is performed locally and the objects are saved
3556 in the source directory. One of the two methods can be used to change
3557 this behavior and build U-Boot to some external directory:
3558
3559 1. Add O= to the make command line invocations:
3560
3561 make O=/tmp/build distclean
3562 make O=/tmp/build NAME_defconfig
3563 make O=/tmp/build all
3564
3565 2. Set environment variable KBUILD_OUTPUT to point to the desired location:
3566
3567 export KBUILD_OUTPUT=/tmp/build
3568 make distclean
3569 make NAME_defconfig
3570 make all
3571
3572 Note that the command line "O=" setting overrides the KBUILD_OUTPUT environment
3573 variable.
3574
3575 User specific CPPFLAGS, AFLAGS and CFLAGS can be passed to the compiler by
3576 setting the according environment variables KCPPFLAGS, KAFLAGS and KCFLAGS.
3577 For example to treat all compiler warnings as errors:
3578
3579 make KCFLAGS=-Werror
3580
3581 Please be aware that the Makefiles assume you are using GNU make, so
3582 for instance on NetBSD you might need to use "gmake" instead of
3583 native "make".
3584
3585
3586 If the system board that you have is not listed, then you will need
3587 to port U-Boot to your hardware platform. To do this, follow these
3588 steps:
3589
3590 1. Create a new directory to hold your board specific code. Add any
3591 files you need. In your board directory, you will need at least
3592 the "Makefile" and a "<board>.c".
3593 2. Create a new configuration file "include/configs/<board>.h" for
3594 your board.
3595 3. If you're porting U-Boot to a new CPU, then also create a new
3596 directory to hold your CPU specific code. Add any files you need.
3597 4. Run "make <board>_defconfig" with your new name.
3598 5. Type "make", and you should get a working "u-boot.srec" file
3599 to be installed on your target system.
3600 6. Debug and solve any problems that might arise.
3601 [Of course, this last step is much harder than it sounds.]
3602
3603
3604 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3605 ==============================================================
3606
3607 If you have modified U-Boot sources (for instance added a new board
3608 or support for new devices, a new CPU, etc.) you are expected to
3609 provide feedback to the other developers. The feedback normally takes
3610 the form of a "patch", i. e. a context diff against a certain (latest
3611 official or latest in the git repository) version of U-Boot sources.
3612
3613 But before you submit such a patch, please verify that your modifi-
3614 cation did not break existing code. At least make sure that *ALL* of
3615 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3616 just run the buildman script (tools/buildman/buildman), which will
3617 configure and build U-Boot for ALL supported system. Be warned, this
3618 will take a while. Please see the buildman README, or run 'buildman -H'
3619 for documentation.
3620
3621
3622 See also "U-Boot Porting Guide" below.
3623
3624
3625 Monitor Commands - Overview:
3626 ============================
3627
3628 go - start application at address 'addr'
3629 run - run commands in an environment variable
3630 bootm - boot application image from memory
3631 bootp - boot image via network using BootP/TFTP protocol
3632 bootz - boot zImage from memory
3633 tftpboot- boot image via network using TFTP protocol
3634 and env variables "ipaddr" and "serverip"
3635 (and eventually "gatewayip")
3636 tftpput - upload a file via network using TFTP protocol
3637 rarpboot- boot image via network using RARP/TFTP protocol
3638 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3639 loads - load S-Record file over serial line
3640 loadb - load binary file over serial line (kermit mode)
3641 md - memory display
3642 mm - memory modify (auto-incrementing)
3643 nm - memory modify (constant address)
3644 mw - memory write (fill)
3645 cp - memory copy
3646 cmp - memory compare
3647 crc32 - checksum calculation
3648 i2c - I2C sub-system
3649 sspi - SPI utility commands
3650 base - print or set address offset
3651 printenv- print environment variables
3652 setenv - set environment variables
3653 saveenv - save environment variables to persistent storage
3654 protect - enable or disable FLASH write protection
3655 erase - erase FLASH memory
3656 flinfo - print FLASH memory information
3657 nand - NAND memory operations (see doc/README.nand)
3658 bdinfo - print Board Info structure
3659 iminfo - print header information for application image
3660 coninfo - print console devices and informations
3661 ide - IDE sub-system
3662 loop - infinite loop on address range
3663 loopw - infinite write loop on address range
3664 mtest - simple RAM test
3665 icache - enable or disable instruction cache
3666 dcache - enable or disable data cache
3667 reset - Perform RESET of the CPU
3668 echo - echo args to console
3669 version - print monitor version
3670 help - print online help
3671 ? - alias for 'help'
3672
3673
3674 Monitor Commands - Detailed Description:
3675 ========================================
3676
3677 TODO.
3678
3679 For now: just type "help <command>".
3680
3681
3682 Environment Variables:
3683 ======================
3684
3685 U-Boot supports user configuration using Environment Variables which
3686 can be made persistent by saving to Flash memory.
3687
3688 Environment Variables are set using "setenv", printed using
3689 "printenv", and saved to Flash using "saveenv". Using "setenv"
3690 without a value can be used to delete a variable from the
3691 environment. As long as you don't save the environment you are
3692 working with an in-memory copy. In case the Flash area containing the
3693 environment is erased by accident, a default environment is provided.
3694
3695 Some configuration options can be set using Environment Variables.
3696
3697 List of environment variables (most likely not complete):
3698
3699 baudrate - see CONFIG_BAUDRATE
3700
3701 bootdelay - see CONFIG_BOOTDELAY
3702
3703 bootcmd - see CONFIG_BOOTCOMMAND
3704
3705 bootargs - Boot arguments when booting an RTOS image
3706
3707 bootfile - Name of the image to load with TFTP
3708
3709 bootm_low - Memory range available for image processing in the bootm
3710 command can be restricted. This variable is given as
3711 a hexadecimal number and defines lowest address allowed
3712 for use by the bootm command. See also "bootm_size"
3713 environment variable. Address defined by "bootm_low" is
3714 also the base of the initial memory mapping for the Linux
3715 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3716 bootm_mapsize.
3717
3718 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3719 This variable is given as a hexadecimal number and it
3720 defines the size of the memory region starting at base
3721 address bootm_low that is accessible by the Linux kernel
3722 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3723 as the default value if it is defined, and bootm_size is
3724 used otherwise.
3725
3726 bootm_size - Memory range available for image processing in the bootm
3727 command can be restricted. This variable is given as
3728 a hexadecimal number and defines the size of the region
3729 allowed for use by the bootm command. See also "bootm_low"
3730 environment variable.
3731
3732 updatefile - Location of the software update file on a TFTP server, used
3733 by the automatic software update feature. Please refer to
3734 documentation in doc/README.update for more details.
3735
3736 autoload - if set to "no" (any string beginning with 'n'),
3737 "bootp" will just load perform a lookup of the
3738 configuration from the BOOTP server, but not try to
3739 load any image using TFTP
3740
3741 autostart - if set to "yes", an image loaded using the "bootp",
3742 "rarpboot", "tftpboot" or "diskboot" commands will
3743 be automatically started (by internally calling
3744 "bootm")
3745
3746 If set to "no", a standalone image passed to the
3747 "bootm" command will be copied to the load address
3748 (and eventually uncompressed), but NOT be started.
3749 This can be used to load and uncompress arbitrary
3750 data.
3751
3752 fdt_high - if set this restricts the maximum address that the
3753 flattened device tree will be copied into upon boot.
3754 For example, if you have a system with 1 GB memory
3755 at physical address 0x10000000, while Linux kernel
3756 only recognizes the first 704 MB as low memory, you
3757 may need to set fdt_high as 0x3C000000 to have the
3758 device tree blob be copied to the maximum address
3759 of the 704 MB low memory, so that Linux kernel can
3760 access it during the boot procedure.
3761
3762 If this is set to the special value 0xFFFFFFFF then
3763 the fdt will not be copied at all on boot. For this
3764 to work it must reside in writable memory, have
3765 sufficient padding on the end of it for u-boot to
3766 add the information it needs into it, and the memory
3767 must be accessible by the kernel.
3768
3769 fdtcontroladdr- if set this is the address of the control flattened
3770 device tree used by U-Boot when CONFIG_OF_CONTROL is
3771 defined.
3772
3773 i2cfast - (PPC405GP|PPC405EP only)
3774 if set to 'y' configures Linux I2C driver for fast
3775 mode (400kHZ). This environment variable is used in
3776 initialization code. So, for changes to be effective
3777 it must be saved and board must be reset.
3778
3779 initrd_high - restrict positioning of initrd images:
3780 If this variable is not set, initrd images will be
3781 copied to the highest possible address in RAM; this
3782 is usually what you want since it allows for
3783 maximum initrd size. If for some reason you want to
3784 make sure that the initrd image is loaded below the
3785 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3786 variable to a value of "no" or "off" or "0".
3787 Alternatively, you can set it to a maximum upper
3788 address to use (U-Boot will still check that it
3789 does not overwrite the U-Boot stack and data).
3790
3791 For instance, when you have a system with 16 MB
3792 RAM, and want to reserve 4 MB from use by Linux,
3793 you can do this by adding "mem=12M" to the value of
3794 the "bootargs" variable. However, now you must make
3795 sure that the initrd image is placed in the first
3796 12 MB as well - this can be done with
3797
3798 setenv initrd_high 00c00000
3799
3800 If you set initrd_high to 0xFFFFFFFF, this is an
3801 indication to U-Boot that all addresses are legal
3802 for the Linux kernel, including addresses in flash
3803 memory. In this case U-Boot will NOT COPY the
3804 ramdisk at all. This may be useful to reduce the
3805 boot time on your system, but requires that this
3806 feature is supported by your Linux kernel.
3807
3808 ipaddr - IP address; needed for tftpboot command
3809
3810 loadaddr - Default load address for commands like "bootp",
3811 "rarpboot", "tftpboot", "loadb" or "diskboot"
3812
3813 loads_echo - see CONFIG_LOADS_ECHO
3814
3815 serverip - TFTP server IP address; needed for tftpboot command
3816
3817 bootretry - see CONFIG_BOOT_RETRY_TIME
3818
3819 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3820
3821 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3822
3823 ethprime - controls which interface is used first.
3824
3825 ethact - controls which interface is currently active.
3826 For example you can do the following
3827
3828 => setenv ethact FEC
3829 => ping 192.168.0.1 # traffic sent on FEC
3830 => setenv ethact SCC
3831 => ping 10.0.0.1 # traffic sent on SCC
3832
3833 ethrotate - When set to "no" U-Boot does not go through all
3834 available network interfaces.
3835 It just stays at the currently selected interface.
3836
3837 netretry - When set to "no" each network operation will
3838 either succeed or fail without retrying.
3839 When set to "once" the network operation will
3840 fail when all the available network interfaces
3841 are tried once without success.
3842 Useful on scripts which control the retry operation
3843 themselves.
3844
3845 npe_ucode - set load address for the NPE microcode
3846
3847 silent_linux - If set then Linux will be told to boot silently, by
3848 changing the console to be empty. If "yes" it will be
3849 made silent. If "no" it will not be made silent. If
3850 unset, then it will be made silent if the U-Boot console
3851 is silent.
3852
3853 tftpsrcp - If this is set, the value is used for TFTP's
3854 UDP source port.
3855
3856 tftpdstp - If this is set, the value is used for TFTP's UDP
3857 destination port instead of the Well Know Port 69.
3858
3859 tftpblocksize - Block size to use for TFTP transfers; if not set,
3860 we use the TFTP server's default block size
3861
3862 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3863 seconds, minimum value is 1000 = 1 second). Defines
3864 when a packet is considered to be lost so it has to
3865 be retransmitted. The default is 5000 = 5 seconds.
3866 Lowering this value may make downloads succeed
3867 faster in networks with high packet loss rates or
3868 with unreliable TFTP servers.
3869
3870 tftptimeoutcountmax - maximum count of TFTP timeouts (no
3871 unit, minimum value = 0). Defines how many timeouts
3872 can happen during a single file transfer before that
3873 transfer is aborted. The default is 10, and 0 means
3874 'no timeouts allowed'. Increasing this value may help
3875 downloads succeed with high packet loss rates, or with
3876 unreliable TFTP servers or client hardware.
3877
3878 vlan - When set to a value < 4095 the traffic over
3879 Ethernet is encapsulated/received over 802.1q
3880 VLAN tagged frames.
3881
3882 bootpretryperiod - Period during which BOOTP/DHCP sends retries.
3883 Unsigned value, in milliseconds. If not set, the period will
3884 be either the default (28000), or a value based on
3885 CONFIG_NET_RETRY_COUNT, if defined. This value has
3886 precedence over the valu based on CONFIG_NET_RETRY_COUNT.
3887
3888 The following image location variables contain the location of images
3889 used in booting. The "Image" column gives the role of the image and is
3890 not an environment variable name. The other columns are environment
3891 variable names. "File Name" gives the name of the file on a TFTP
3892 server, "RAM Address" gives the location in RAM the image will be
3893 loaded to, and "Flash Location" gives the image's address in NOR
3894 flash or offset in NAND flash.
3895
3896 *Note* - these variables don't have to be defined for all boards, some
3897 boards currently use other variables for these purposes, and some
3898 boards use these variables for other purposes.
3899
3900 Image File Name RAM Address Flash Location
3901 ----- --------- ----------- --------------
3902 u-boot u-boot u-boot_addr_r u-boot_addr
3903 Linux kernel bootfile kernel_addr_r kernel_addr
3904 device tree blob fdtfile fdt_addr_r fdt_addr
3905 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
3906
3907 The following environment variables may be used and automatically
3908 updated by the network boot commands ("bootp" and "rarpboot"),
3909 depending the information provided by your boot server:
3910
3911 bootfile - see above
3912 dnsip - IP address of your Domain Name Server
3913 dnsip2 - IP address of your secondary Domain Name Server
3914 gatewayip - IP address of the Gateway (Router) to use
3915 hostname - Target hostname
3916 ipaddr - see above
3917 netmask - Subnet Mask
3918 rootpath - Pathname of the root filesystem on the NFS server
3919 serverip - see above
3920
3921
3922 There are two special Environment Variables:
3923
3924 serial# - contains hardware identification information such
3925 as type string and/or serial number
3926 ethaddr - Ethernet address
3927
3928 These variables can be set only once (usually during manufacturing of
3929 the board). U-Boot refuses to delete or overwrite these variables
3930 once they have been set once.
3931
3932
3933 Further special Environment Variables:
3934
3935 ver - Contains the U-Boot version string as printed
3936 with the "version" command. This variable is
3937 readonly (see CONFIG_VERSION_VARIABLE).
3938
3939
3940 Please note that changes to some configuration parameters may take
3941 only effect after the next boot (yes, that's just like Windoze :-).
3942
3943
3944 Callback functions for environment variables:
3945 ---------------------------------------------
3946
3947 For some environment variables, the behavior of u-boot needs to change
3948 when their values are changed. This functionality allows functions to
3949 be associated with arbitrary variables. On creation, overwrite, or
3950 deletion, the callback will provide the opportunity for some side
3951 effect to happen or for the change to be rejected.
3952
3953 The callbacks are named and associated with a function using the
3954 U_BOOT_ENV_CALLBACK macro in your board or driver code.
3955
3956 These callbacks are associated with variables in one of two ways. The
3957 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
3958 in the board configuration to a string that defines a list of
3959 associations. The list must be in the following format:
3960
3961 entry = variable_name[:callback_name]
3962 list = entry[,list]
3963
3964 If the callback name is not specified, then the callback is deleted.
3965 Spaces are also allowed anywhere in the list.
3966
3967 Callbacks can also be associated by defining the ".callbacks" variable
3968 with the same list format above. Any association in ".callbacks" will
3969 override any association in the static list. You can define
3970 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
3971 ".callbacks" environment variable in the default or embedded environment.
3972
3973 If CONFIG_REGEX is defined, the variable_name above is evaluated as a
3974 regular expression. This allows multiple variables to be connected to
3975 the same callback without explicitly listing them all out.
3976
3977
3978 Command Line Parsing:
3979 =====================
3980
3981 There are two different command line parsers available with U-Boot:
3982 the old "simple" one, and the much more powerful "hush" shell:
3983
3984 Old, simple command line parser:
3985 --------------------------------
3986
3987 - supports environment variables (through setenv / saveenv commands)
3988 - several commands on one line, separated by ';'
3989 - variable substitution using "... ${name} ..." syntax
3990 - special characters ('$', ';') can be escaped by prefixing with '\',
3991 for example:
3992 setenv bootcmd bootm \${address}
3993 - You can also escape text by enclosing in single apostrophes, for example:
3994 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3995
3996 Hush shell:
3997 -----------
3998
3999 - similar to Bourne shell, with control structures like
4000 if...then...else...fi, for...do...done; while...do...done,
4001 until...do...done, ...
4002 - supports environment ("global") variables (through setenv / saveenv
4003 commands) and local shell variables (through standard shell syntax
4004 "name=value"); only environment variables can be used with "run"
4005 command
4006
4007 General rules:
4008 --------------
4009
4010 (1) If a command line (or an environment variable executed by a "run"
4011 command) contains several commands separated by semicolon, and
4012 one of these commands fails, then the remaining commands will be
4013 executed anyway.
4014
4015 (2) If you execute several variables with one call to run (i. e.
4016 calling run with a list of variables as arguments), any failing
4017 command will cause "run" to terminate, i. e. the remaining
4018 variables are not executed.
4019
4020 Note for Redundant Ethernet Interfaces:
4021 =======================================
4022
4023 Some boards come with redundant Ethernet interfaces; U-Boot supports
4024 such configurations and is capable of automatic selection of a
4025 "working" interface when needed. MAC assignment works as follows:
4026
4027 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
4028 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
4029 "eth1addr" (=>eth1), "eth2addr", ...
4030
4031 If the network interface stores some valid MAC address (for instance
4032 in SROM), this is used as default address if there is NO correspon-
4033 ding setting in the environment; if the corresponding environment
4034 variable is set, this overrides the settings in the card; that means:
4035
4036 o If the SROM has a valid MAC address, and there is no address in the
4037 environment, the SROM's address is used.
4038
4039 o If there is no valid address in the SROM, and a definition in the
4040 environment exists, then the value from the environment variable is
4041 used.
4042
4043 o If both the SROM and the environment contain a MAC address, and
4044 both addresses are the same, this MAC address is used.
4045
4046 o If both the SROM and the environment contain a MAC address, and the
4047 addresses differ, the value from the environment is used and a
4048 warning is printed.
4049
4050 o If neither SROM nor the environment contain a MAC address, an error
4051 is raised. If CONFIG_NET_RANDOM_ETHADDR is defined, then in this case
4052 a random, locally-assigned MAC is used.
4053
4054 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
4055 will be programmed into hardware as part of the initialization process. This
4056 may be skipped by setting the appropriate 'ethmacskip' environment variable.
4057 The naming convention is as follows:
4058 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
4059
4060 Image Formats:
4061 ==============
4062
4063 U-Boot is capable of booting (and performing other auxiliary operations on)
4064 images in two formats:
4065
4066 New uImage format (FIT)
4067 -----------------------
4068
4069 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
4070 to Flattened Device Tree). It allows the use of images with multiple
4071 components (several kernels, ramdisks, etc.), with contents protected by
4072 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
4073
4074
4075 Old uImage format
4076 -----------------
4077
4078 Old image format is based on binary files which can be basically anything,
4079 preceded by a special header; see the definitions in include/image.h for
4080 details; basically, the header defines the following image properties:
4081
4082 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
4083 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
4084 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
4085 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
4086 INTEGRITY).
4087 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
4088 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
4089 Currently supported: ARM, Intel x86, MIPS, NDS32, Nios II, PowerPC).
4090 * Compression Type (uncompressed, gzip, bzip2)
4091 * Load Address
4092 * Entry Point
4093 * Image Name
4094 * Image Timestamp
4095
4096 The header is marked by a special Magic Number, and both the header
4097 and the data portions of the image are secured against corruption by
4098 CRC32 checksums.
4099
4100
4101 Linux Support:
4102 ==============
4103
4104 Although U-Boot should support any OS or standalone application
4105 easily, the main focus has always been on Linux during the design of
4106 U-Boot.
4107
4108 U-Boot includes many features that so far have been part of some
4109 special "boot loader" code within the Linux kernel. Also, any
4110 "initrd" images to be used are no longer part of one big Linux image;
4111 instead, kernel and "initrd" are separate images. This implementation
4112 serves several purposes:
4113
4114 - the same features can be used for other OS or standalone
4115 applications (for instance: using compressed images to reduce the
4116 Flash memory footprint)
4117
4118 - it becomes much easier to port new Linux kernel versions because
4119 lots of low-level, hardware dependent stuff are done by U-Boot
4120
4121 - the same Linux kernel image can now be used with different "initrd"
4122 images; of course this also means that different kernel images can
4123 be run with the same "initrd". This makes testing easier (you don't
4124 have to build a new "zImage.initrd" Linux image when you just
4125 change a file in your "initrd"). Also, a field-upgrade of the
4126 software is easier now.
4127
4128
4129 Linux HOWTO:
4130 ============
4131
4132 Porting Linux to U-Boot based systems:
4133 ---------------------------------------
4134
4135 U-Boot cannot save you from doing all the necessary modifications to
4136 configure the Linux device drivers for use with your target hardware
4137 (no, we don't intend to provide a full virtual machine interface to
4138 Linux :-).
4139
4140 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
4141
4142 Just make sure your machine specific header file (for instance
4143 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
4144 Information structure as we define in include/asm-<arch>/u-boot.h,
4145 and make sure that your definition of IMAP_ADDR uses the same value
4146 as your U-Boot configuration in CONFIG_SYS_IMMR.
4147
4148 Note that U-Boot now has a driver model, a unified model for drivers.
4149 If you are adding a new driver, plumb it into driver model. If there
4150 is no uclass available, you are encouraged to create one. See
4151 doc/driver-model.
4152
4153
4154 Configuring the Linux kernel:
4155 -----------------------------
4156
4157 No specific requirements for U-Boot. Make sure you have some root
4158 device (initial ramdisk, NFS) for your target system.
4159
4160
4161 Building a Linux Image:
4162 -----------------------
4163
4164 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
4165 not used. If you use recent kernel source, a new build target
4166 "uImage" will exist which automatically builds an image usable by
4167 U-Boot. Most older kernels also have support for a "pImage" target,
4168 which was introduced for our predecessor project PPCBoot and uses a
4169 100% compatible format.
4170
4171 Example:
4172
4173 make TQM850L_defconfig
4174 make oldconfig
4175 make dep
4176 make uImage
4177
4178 The "uImage" build target uses a special tool (in 'tools/mkimage') to
4179 encapsulate a compressed Linux kernel image with header information,
4180 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
4181
4182 * build a standard "vmlinux" kernel image (in ELF binary format):
4183
4184 * convert the kernel into a raw binary image:
4185
4186 ${CROSS_COMPILE}-objcopy -O binary \
4187 -R .note -R .comment \
4188 -S vmlinux linux.bin
4189
4190 * compress the binary image:
4191
4192 gzip -9 linux.bin
4193
4194 * package compressed binary image for U-Boot:
4195
4196 mkimage -A ppc -O linux -T kernel -C gzip \
4197 -a 0 -e 0 -n "Linux Kernel Image" \
4198 -d linux.bin.gz uImage
4199
4200
4201 The "mkimage" tool can also be used to create ramdisk images for use
4202 with U-Boot, either separated from the Linux kernel image, or
4203 combined into one file. "mkimage" encapsulates the images with a 64
4204 byte header containing information about target architecture,
4205 operating system, image type, compression method, entry points, time
4206 stamp, CRC32 checksums, etc.
4207
4208 "mkimage" can be called in two ways: to verify existing images and
4209 print the header information, or to build new images.
4210
4211 In the first form (with "-l" option) mkimage lists the information
4212 contained in the header of an existing U-Boot image; this includes
4213 checksum verification:
4214
4215 tools/mkimage -l image
4216 -l ==> list image header information
4217
4218 The second form (with "-d" option) is used to build a U-Boot image
4219 from a "data file" which is used as image payload:
4220
4221 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
4222 -n name -d data_file image
4223 -A ==> set architecture to 'arch'
4224 -O ==> set operating system to 'os'
4225 -T ==> set image type to 'type'
4226 -C ==> set compression type 'comp'
4227 -a ==> set load address to 'addr' (hex)
4228 -e ==> set entry point to 'ep' (hex)
4229 -n ==> set image name to 'name'
4230 -d ==> use image data from 'datafile'
4231
4232 Right now, all Linux kernels for PowerPC systems use the same load
4233 address (0x00000000), but the entry point address depends on the
4234 kernel version:
4235
4236 - 2.2.x kernels have the entry point at 0x0000000C,
4237 - 2.3.x and later kernels have the entry point at 0x00000000.
4238
4239 So a typical call to build a U-Boot image would read:
4240
4241 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4242 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
4243 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
4244 > examples/uImage.TQM850L
4245 Image Name: 2.4.4 kernel for TQM850L
4246 Created: Wed Jul 19 02:34:59 2000
4247 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4248 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4249 Load Address: 0x00000000
4250 Entry Point: 0x00000000
4251
4252 To verify the contents of the image (or check for corruption):
4253
4254 -> tools/mkimage -l examples/uImage.TQM850L
4255 Image Name: 2.4.4 kernel for TQM850L
4256 Created: Wed Jul 19 02:34:59 2000
4257 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4258 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
4259 Load Address: 0x00000000
4260 Entry Point: 0x00000000
4261
4262 NOTE: for embedded systems where boot time is critical you can trade
4263 speed for memory and install an UNCOMPRESSED image instead: this
4264 needs more space in Flash, but boots much faster since it does not
4265 need to be uncompressed:
4266
4267 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
4268 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
4269 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
4270 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
4271 > examples/uImage.TQM850L-uncompressed
4272 Image Name: 2.4.4 kernel for TQM850L
4273 Created: Wed Jul 19 02:34:59 2000
4274 Image Type: PowerPC Linux Kernel Image (uncompressed)
4275 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
4276 Load Address: 0x00000000
4277 Entry Point: 0x00000000
4278
4279
4280 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
4281 when your kernel is intended to use an initial ramdisk:
4282
4283 -> tools/mkimage -n 'Simple Ramdisk Image' \
4284 > -A ppc -O linux -T ramdisk -C gzip \
4285 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
4286 Image Name: Simple Ramdisk Image
4287 Created: Wed Jan 12 14:01:50 2000
4288 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4289 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
4290 Load Address: 0x00000000
4291 Entry Point: 0x00000000
4292
4293 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
4294 option performs the converse operation of the mkimage's second form (the "-d"
4295 option). Given an image built by mkimage, the dumpimage extracts a "data file"
4296 from the image:
4297
4298 tools/dumpimage -i image -T type -p position data_file
4299 -i ==> extract from the 'image' a specific 'data_file'
4300 -T ==> set image type to 'type'
4301 -p ==> 'position' (starting at 0) of the 'data_file' inside the 'image'
4302
4303
4304 Installing a Linux Image:
4305 -------------------------
4306
4307 To downloading a U-Boot image over the serial (console) interface,
4308 you must convert the image to S-Record format:
4309
4310 objcopy -I binary -O srec examples/image examples/image.srec
4311
4312 The 'objcopy' does not understand the information in the U-Boot
4313 image header, so the resulting S-Record file will be relative to
4314 address 0x00000000. To load it to a given address, you need to
4315 specify the target address as 'offset' parameter with the 'loads'
4316 command.
4317
4318 Example: install the image to address 0x40100000 (which on the
4319 TQM8xxL is in the first Flash bank):
4320
4321 => erase 40100000 401FFFFF
4322
4323 .......... done
4324 Erased 8 sectors
4325
4326 => loads 40100000
4327 ## Ready for S-Record download ...
4328 ~>examples/image.srec
4329 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
4330 ...
4331 15989 15990 15991 15992
4332 [file transfer complete]
4333 [connected]
4334 ## Start Addr = 0x00000000
4335
4336
4337 You can check the success of the download using the 'iminfo' command;
4338 this includes a checksum verification so you can be sure no data
4339 corruption happened:
4340
4341 => imi 40100000
4342
4343 ## Checking Image at 40100000 ...
4344 Image Name: 2.2.13 for initrd on TQM850L
4345 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4346 Data Size: 335725 Bytes = 327 kB = 0 MB
4347 Load Address: 00000000
4348 Entry Point: 0000000c
4349 Verifying Checksum ... OK
4350
4351
4352 Boot Linux:
4353 -----------
4354
4355 The "bootm" command is used to boot an application that is stored in
4356 memory (RAM or Flash). In case of a Linux kernel image, the contents
4357 of the "bootargs" environment variable is passed to the kernel as
4358 parameters. You can check and modify this variable using the
4359 "printenv" and "setenv" commands:
4360
4361
4362 => printenv bootargs
4363 bootargs=root=/dev/ram
4364
4365 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4366
4367 => printenv bootargs
4368 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4369
4370 => bootm 40020000
4371 ## Booting Linux kernel at 40020000 ...
4372 Image Name: 2.2.13 for NFS on TQM850L
4373 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4374 Data Size: 381681 Bytes = 372 kB = 0 MB
4375 Load Address: 00000000
4376 Entry Point: 0000000c
4377 Verifying Checksum ... OK
4378 Uncompressing Kernel Image ... OK
4379 Linux version 2.2.13 (wd (a] denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:35:17 MEST 2000
4380 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4381 time_init: decrementer frequency = 187500000/60
4382 Calibrating delay loop... 49.77 BogoMIPS
4383 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4384 ...
4385
4386 If you want to boot a Linux kernel with initial RAM disk, you pass
4387 the memory addresses of both the kernel and the initrd image (PPBCOOT
4388 format!) to the "bootm" command:
4389
4390 => imi 40100000 40200000
4391
4392 ## Checking Image at 40100000 ...
4393 Image Name: 2.2.13 for initrd on TQM850L
4394 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4395 Data Size: 335725 Bytes = 327 kB = 0 MB
4396 Load Address: 00000000
4397 Entry Point: 0000000c
4398 Verifying Checksum ... OK
4399
4400 ## Checking Image at 40200000 ...
4401 Image Name: Simple Ramdisk Image
4402 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4403 Data Size: 566530 Bytes = 553 kB = 0 MB
4404 Load Address: 00000000
4405 Entry Point: 00000000
4406 Verifying Checksum ... OK
4407
4408 => bootm 40100000 40200000
4409 ## Booting Linux kernel at 40100000 ...
4410 Image Name: 2.2.13 for initrd on TQM850L
4411 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4412 Data Size: 335725 Bytes = 327 kB = 0 MB
4413 Load Address: 00000000
4414 Entry Point: 0000000c
4415 Verifying Checksum ... OK
4416 Uncompressing Kernel Image ... OK
4417 ## Loading RAMDisk Image at 40200000 ...
4418 Image Name: Simple Ramdisk Image
4419 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4420 Data Size: 566530 Bytes = 553 kB = 0 MB
4421 Load Address: 00000000
4422 Entry Point: 00000000
4423 Verifying Checksum ... OK
4424 Loading Ramdisk ... OK
4425 Linux version 2.2.13 (wd (a] denx.local.net) (gcc version 2.95.2 19991024 (release)) #1 Wed Jul 19 02:32:08 MEST 2000
4426 Boot arguments: root=/dev/ram
4427 time_init: decrementer frequency = 187500000/60
4428 Calibrating delay loop... 49.77 BogoMIPS
4429 ...
4430 RAMDISK: Compressed image found at block 0
4431 VFS: Mounted root (ext2 filesystem).
4432
4433 bash#
4434
4435 Boot Linux and pass a flat device tree:
4436 -----------
4437
4438 First, U-Boot must be compiled with the appropriate defines. See the section
4439 titled "Linux Kernel Interface" above for a more in depth explanation. The
4440 following is an example of how to start a kernel and pass an updated
4441 flat device tree:
4442
4443 => print oftaddr
4444 oftaddr=0x300000
4445 => print oft
4446 oft=oftrees/mpc8540ads.dtb
4447 => tftp $oftaddr $oft
4448 Speed: 1000, full duplex
4449 Using TSEC0 device
4450 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4451 Filename 'oftrees/mpc8540ads.dtb'.
4452 Load address: 0x300000
4453 Loading: #
4454 done
4455 Bytes transferred = 4106 (100a hex)
4456 => tftp $loadaddr $bootfile
4457 Speed: 1000, full duplex
4458 Using TSEC0 device
4459 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4460 Filename 'uImage'.
4461 Load address: 0x200000
4462 Loading:############
4463 done
4464 Bytes transferred = 1029407 (fb51f hex)
4465 => print loadaddr
4466 loadaddr=200000
4467 => print oftaddr
4468 oftaddr=0x300000
4469 => bootm $loadaddr - $oftaddr
4470 ## Booting image at 00200000 ...
4471 Image Name: Linux-2.6.17-dirty
4472 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4473 Data Size: 1029343 Bytes = 1005.2 kB
4474 Load Address: 00000000
4475 Entry Point: 00000000
4476 Verifying Checksum ... OK
4477 Uncompressing Kernel Image ... OK
4478 Booting using flat device tree at 0x300000
4479 Using MPC85xx ADS machine description
4480 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4481 [snip]
4482
4483
4484 More About U-Boot Image Types:
4485 ------------------------------
4486
4487 U-Boot supports the following image types:
4488
4489 "Standalone Programs" are directly runnable in the environment
4490 provided by U-Boot; it is expected that (if they behave
4491 well) you can continue to work in U-Boot after return from
4492 the Standalone Program.
4493 "OS Kernel Images" are usually images of some Embedded OS which
4494 will take over control completely. Usually these programs
4495 will install their own set of exception handlers, device
4496 drivers, set up the MMU, etc. - this means, that you cannot
4497 expect to re-enter U-Boot except by resetting the CPU.
4498 "RAMDisk Images" are more or less just data blocks, and their
4499 parameters (address, size) are passed to an OS kernel that is
4500 being started.
4501 "Multi-File Images" contain several images, typically an OS
4502 (Linux) kernel image and one or more data images like
4503 RAMDisks. This construct is useful for instance when you want
4504 to boot over the network using BOOTP etc., where the boot
4505 server provides just a single image file, but you want to get
4506 for instance an OS kernel and a RAMDisk image.
4507
4508 "Multi-File Images" start with a list of image sizes, each
4509 image size (in bytes) specified by an "uint32_t" in network
4510 byte order. This list is terminated by an "(uint32_t)0".
4511 Immediately after the terminating 0 follow the images, one by
4512 one, all aligned on "uint32_t" boundaries (size rounded up to
4513 a multiple of 4 bytes).
4514
4515 "Firmware Images" are binary images containing firmware (like
4516 U-Boot or FPGA images) which usually will be programmed to
4517 flash memory.
4518
4519 "Script files" are command sequences that will be executed by
4520 U-Boot's command interpreter; this feature is especially
4521 useful when you configure U-Boot to use a real shell (hush)
4522 as command interpreter.
4523
4524 Booting the Linux zImage:
4525 -------------------------
4526
4527 On some platforms, it's possible to boot Linux zImage. This is done
4528 using the "bootz" command. The syntax of "bootz" command is the same
4529 as the syntax of "bootm" command.
4530
4531 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
4532 kernel with raw initrd images. The syntax is slightly different, the
4533 address of the initrd must be augmented by it's size, in the following
4534 format: "<initrd addres>:<initrd size>".
4535
4536
4537 Standalone HOWTO:
4538 =================
4539
4540 One of the features of U-Boot is that you can dynamically load and
4541 run "standalone" applications, which can use some resources of
4542 U-Boot like console I/O functions or interrupt services.
4543
4544 Two simple examples are included with the sources:
4545
4546 "Hello World" Demo:
4547 -------------------
4548
4549 'examples/hello_world.c' contains a small "Hello World" Demo
4550 application; it is automatically compiled when you build U-Boot.
4551 It's configured to run at address 0x00040004, so you can play with it
4552 like that:
4553
4554 => loads
4555 ## Ready for S-Record download ...
4556 ~>examples/hello_world.srec
4557 1 2 3 4 5 6 7 8 9 10 11 ...
4558 [file transfer complete]
4559 [connected]
4560 ## Start Addr = 0x00040004
4561
4562 => go 40004 Hello World! This is a test.
4563 ## Starting application at 0x00040004 ...
4564 Hello World
4565 argc = 7
4566 argv[0] = "40004"
4567 argv[1] = "Hello"
4568 argv[2] = "World!"
4569 argv[3] = "This"
4570 argv[4] = "is"
4571 argv[5] = "a"
4572 argv[6] = "test."
4573 argv[7] = "<NULL>"
4574 Hit any key to exit ...
4575
4576 ## Application terminated, rc = 0x0
4577
4578 Another example, which demonstrates how to register a CPM interrupt
4579 handler with the U-Boot code, can be found in 'examples/timer.c'.
4580 Here, a CPM timer is set up to generate an interrupt every second.
4581 The interrupt service routine is trivial, just printing a '.'
4582 character, but this is just a demo program. The application can be
4583 controlled by the following keys:
4584
4585 ? - print current values og the CPM Timer registers
4586 b - enable interrupts and start timer
4587 e - stop timer and disable interrupts
4588 q - quit application
4589
4590 => loads
4591 ## Ready for S-Record download ...
4592 ~>examples/timer.srec
4593 1 2 3 4 5 6 7 8 9 10 11 ...
4594 [file transfer complete]
4595 [connected]
4596 ## Start Addr = 0x00040004
4597
4598 => go 40004
4599 ## Starting application at 0x00040004 ...
4600 TIMERS=0xfff00980
4601 Using timer 1
4602 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4603
4604 Hit 'b':
4605 [q, b, e, ?] Set interval 1000000 us
4606 Enabling timer
4607 Hit '?':
4608 [q, b, e, ?] ........
4609 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4610 Hit '?':
4611 [q, b, e, ?] .
4612 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4613 Hit '?':
4614 [q, b, e, ?] .
4615 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4616 Hit '?':
4617 [q, b, e, ?] .
4618 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4619 Hit 'e':
4620 [q, b, e, ?] ...Stopping timer
4621 Hit 'q':
4622 [q, b, e, ?] ## Application terminated, rc = 0x0
4623
4624
4625 Minicom warning:
4626 ================
4627
4628 Over time, many people have reported problems when trying to use the
4629 "minicom" terminal emulation program for serial download. I (wd)
4630 consider minicom to be broken, and recommend not to use it. Under
4631 Unix, I recommend to use C-Kermit for general purpose use (and
4632 especially for kermit binary protocol download ("loadb" command), and
4633 use "cu" for S-Record download ("loads" command). See
4634 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
4635 for help with kermit.
4636
4637
4638 Nevertheless, if you absolutely want to use it try adding this
4639 configuration to your "File transfer protocols" section:
4640
4641 Name Program Name U/D FullScr IO-Red. Multi
4642 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4643 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4644
4645
4646 NetBSD Notes:
4647 =============
4648
4649 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4650 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4651
4652 Building requires a cross environment; it is known to work on
4653 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4654 need gmake since the Makefiles are not compatible with BSD make).
4655 Note that the cross-powerpc package does not install include files;
4656 attempting to build U-Boot will fail because <machine/ansi.h> is
4657 missing. This file has to be installed and patched manually:
4658
4659 # cd /usr/pkg/cross/powerpc-netbsd/include
4660 # mkdir powerpc
4661 # ln -s powerpc machine
4662 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4663 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4664
4665 Native builds *don't* work due to incompatibilities between native
4666 and U-Boot include files.
4667
4668 Booting assumes that (the first part of) the image booted is a
4669 stage-2 loader which in turn loads and then invokes the kernel
4670 proper. Loader sources will eventually appear in the NetBSD source
4671 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4672 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4673
4674
4675 Implementation Internals:
4676 =========================
4677
4678 The following is not intended to be a complete description of every
4679 implementation detail. However, it should help to understand the
4680 inner workings of U-Boot and make it easier to port it to custom
4681 hardware.
4682
4683
4684 Initial Stack, Global Data:
4685 ---------------------------
4686
4687 The implementation of U-Boot is complicated by the fact that U-Boot
4688 starts running out of ROM (flash memory), usually without access to
4689 system RAM (because the memory controller is not initialized yet).
4690 This means that we don't have writable Data or BSS segments, and BSS
4691 is not initialized as zero. To be able to get a C environment working
4692 at all, we have to allocate at least a minimal stack. Implementation
4693 options for this are defined and restricted by the CPU used: Some CPU
4694 models provide on-chip memory (like the IMMR area on MPC8xx and
4695 MPC826x processors), on others (parts of) the data cache can be
4696 locked as (mis-) used as memory, etc.
4697
4698 Chris Hallinan posted a good summary of these issues to the
4699 U-Boot mailing list:
4700
4701 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4702 From: "Chris Hallinan" <clh (a] net1plus.com>
4703 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4704 ...
4705
4706 Correct me if I'm wrong, folks, but the way I understand it
4707 is this: Using DCACHE as initial RAM for Stack, etc, does not
4708 require any physical RAM backing up the cache. The cleverness
4709 is that the cache is being used as a temporary supply of
4710 necessary storage before the SDRAM controller is setup. It's
4711 beyond the scope of this list to explain the details, but you
4712 can see how this works by studying the cache architecture and
4713 operation in the architecture and processor-specific manuals.
4714
4715 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4716 is another option for the system designer to use as an
4717 initial stack/RAM area prior to SDRAM being available. Either
4718 option should work for you. Using CS 4 should be fine if your
4719 board designers haven't used it for something that would
4720 cause you grief during the initial boot! It is frequently not
4721 used.
4722
4723 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4724 with your processor/board/system design. The default value
4725 you will find in any recent u-boot distribution in
4726 walnut.h should work for you. I'd set it to a value larger
4727 than your SDRAM module. If you have a 64MB SDRAM module, set
4728 it above 400_0000. Just make sure your board has no resources
4729 that are supposed to respond to that address! That code in
4730 start.S has been around a while and should work as is when
4731 you get the config right.
4732
4733 -Chris Hallinan
4734 DS4.COM, Inc.
4735
4736 It is essential to remember this, since it has some impact on the C
4737 code for the initialization procedures:
4738
4739 * Initialized global data (data segment) is read-only. Do not attempt
4740 to write it.
4741
4742 * Do not use any uninitialized global data (or implicitly initialized
4743 as zero data - BSS segment) at all - this is undefined, initiali-
4744 zation is performed later (when relocating to RAM).
4745
4746 * Stack space is very limited. Avoid big data buffers or things like
4747 that.
4748
4749 Having only the stack as writable memory limits means we cannot use
4750 normal global data to share information between the code. But it
4751 turned out that the implementation of U-Boot can be greatly
4752 simplified by making a global data structure (gd_t) available to all
4753 functions. We could pass a pointer to this data as argument to _all_
4754 functions, but this would bloat the code. Instead we use a feature of
4755 the GCC compiler (Global Register Variables) to share the data: we
4756 place a pointer (gd) to the global data into a register which we
4757 reserve for this purpose.
4758
4759 When choosing a register for such a purpose we are restricted by the
4760 relevant (E)ABI specifications for the current architecture, and by
4761 GCC's implementation.
4762
4763 For PowerPC, the following registers have specific use:
4764 R1: stack pointer
4765 R2: reserved for system use
4766 R3-R4: parameter passing and return values
4767 R5-R10: parameter passing
4768 R13: small data area pointer
4769 R30: GOT pointer
4770 R31: frame pointer
4771
4772 (U-Boot also uses R12 as internal GOT pointer. r12
4773 is a volatile register so r12 needs to be reset when
4774 going back and forth between asm and C)
4775
4776 ==> U-Boot will use R2 to hold a pointer to the global data
4777
4778 Note: on PPC, we could use a static initializer (since the
4779 address of the global data structure is known at compile time),
4780 but it turned out that reserving a register results in somewhat
4781 smaller code - although the code savings are not that big (on
4782 average for all boards 752 bytes for the whole U-Boot image,
4783 624 text + 127 data).
4784
4785 On ARM, the following registers are used:
4786
4787 R0: function argument word/integer result
4788 R1-R3: function argument word
4789 R9: platform specific
4790 R10: stack limit (used only if stack checking is enabled)
4791 R11: argument (frame) pointer
4792 R12: temporary workspace
4793 R13: stack pointer
4794 R14: link register
4795 R15: program counter
4796
4797 ==> U-Boot will use R9 to hold a pointer to the global data
4798
4799 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
4800
4801 On Nios II, the ABI is documented here:
4802 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4803
4804 ==> U-Boot will use gp to hold a pointer to the global data
4805
4806 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4807 to access small data sections, so gp is free.
4808
4809 On NDS32, the following registers are used:
4810
4811 R0-R1: argument/return
4812 R2-R5: argument
4813 R15: temporary register for assembler
4814 R16: trampoline register
4815 R28: frame pointer (FP)
4816 R29: global pointer (GP)
4817 R30: link register (LP)
4818 R31: stack pointer (SP)
4819 PC: program counter (PC)
4820
4821 ==> U-Boot will use R10 to hold a pointer to the global data
4822
4823 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4824 or current versions of GCC may "optimize" the code too much.
4825
4826 On RISC-V, the following registers are used:
4827
4828 x0: hard-wired zero (zero)
4829 x1: return address (ra)
4830 x2: stack pointer (sp)
4831 x3: global pointer (gp)
4832 x4: thread pointer (tp)
4833 x5: link register (t0)
4834 x8: frame pointer (fp)
4835 x10-x11: arguments/return values (a0-1)
4836 x12-x17: arguments (a2-7)
4837 x28-31: temporaries (t3-6)
4838 pc: program counter (pc)
4839
4840 ==> U-Boot will use gp to hold a pointer to the global data
4841
4842 Memory Management:
4843 ------------------
4844
4845 U-Boot runs in system state and uses physical addresses, i.e. the
4846 MMU is not used either for address mapping nor for memory protection.
4847
4848 The available memory is mapped to fixed addresses using the memory
4849 controller. In this process, a contiguous block is formed for each
4850 memory type (Flash, SDRAM, SRAM), even when it consists of several
4851 physical memory banks.
4852
4853 U-Boot is installed in the first 128 kB of the first Flash bank (on
4854 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4855 booting and sizing and initializing DRAM, the code relocates itself
4856 to the upper end of DRAM. Immediately below the U-Boot code some
4857 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4858 configuration setting]. Below that, a structure with global Board
4859 Info data is placed, followed by the stack (growing downward).
4860
4861 Additionally, some exception handler code is copied to the low 8 kB
4862 of DRAM (0x00000000 ... 0x00001FFF).
4863
4864 So a typical memory configuration with 16 MB of DRAM could look like
4865 this:
4866
4867 0x0000 0000 Exception Vector code
4868 :
4869 0x0000 1FFF
4870 0x0000 2000 Free for Application Use
4871 :
4872 :
4873
4874 :
4875 :
4876 0x00FB FF20 Monitor Stack (Growing downward)
4877 0x00FB FFAC Board Info Data and permanent copy of global data
4878 0x00FC 0000 Malloc Arena
4879 :
4880 0x00FD FFFF
4881 0x00FE 0000 RAM Copy of Monitor Code
4882 ... eventually: LCD or video framebuffer
4883 ... eventually: pRAM (Protected RAM - unchanged by reset)
4884 0x00FF FFFF [End of RAM]
4885
4886
4887 System Initialization:
4888 ----------------------
4889
4890 In the reset configuration, U-Boot starts at the reset entry point
4891 (on most PowerPC systems at address 0x00000100). Because of the reset
4892 configuration for CS0# this is a mirror of the on board Flash memory.
4893 To be able to re-map memory U-Boot then jumps to its link address.
4894 To be able to implement the initialization code in C, a (small!)
4895 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4896 which provide such a feature like), or in a locked part of the data
4897 cache. After that, U-Boot initializes the CPU core, the caches and
4898 the SIU.
4899
4900 Next, all (potentially) available memory banks are mapped using a
4901 preliminary mapping. For example, we put them on 512 MB boundaries
4902 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4903 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4904 programmed for SDRAM access. Using the temporary configuration, a
4905 simple memory test is run that determines the size of the SDRAM
4906 banks.
4907
4908 When there is more than one SDRAM bank, and the banks are of
4909 different size, the largest is mapped first. For equal size, the first
4910 bank (CS2#) is mapped first. The first mapping is always for address
4911 0x00000000, with any additional banks following immediately to create
4912 contiguous memory starting from 0.
4913
4914 Then, the monitor installs itself at the upper end of the SDRAM area
4915 and allocates memory for use by malloc() and for the global Board
4916 Info data; also, the exception vector code is copied to the low RAM
4917 pages, and the final stack is set up.
4918
4919 Only after this relocation will you have a "normal" C environment;
4920 until that you are restricted in several ways, mostly because you are
4921 running from ROM, and because the code will have to be relocated to a
4922 new address in RAM.
4923
4924
4925 U-Boot Porting Guide:
4926 ----------------------
4927
4928 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4929 list, October 2002]
4930
4931
4932 int main(int argc, char *argv[])
4933 {
4934 sighandler_t no_more_time;
4935
4936 signal(SIGALRM, no_more_time);
4937 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4938
4939 if (available_money > available_manpower) {
4940 Pay consultant to port U-Boot;
4941 return 0;
4942 }
4943
4944 Download latest U-Boot source;
4945
4946 Subscribe to u-boot mailing list;
4947
4948 if (clueless)
4949 email("Hi, I am new to U-Boot, how do I get started?");
4950
4951 while (learning) {
4952 Read the README file in the top level directory;
4953 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4954 Read applicable doc/*.README;
4955 Read the source, Luke;
4956 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4957 }
4958
4959 if (available_money > toLocalCurrency ($2500))
4960 Buy a BDI3000;
4961 else
4962 Add a lot of aggravation and time;
4963
4964 if (a similar board exists) { /* hopefully... */
4965 cp -a board/<similar> board/<myboard>
4966 cp include/configs/<similar>.h include/configs/<myboard>.h
4967 } else {
4968 Create your own board support subdirectory;
4969 Create your own board include/configs/<myboard>.h file;
4970 }
4971 Edit new board/<myboard> files
4972 Edit new include/configs/<myboard>.h
4973
4974 while (!accepted) {
4975 while (!running) {
4976 do {
4977 Add / modify source code;
4978 } until (compiles);
4979 Debug;
4980 if (clueless)
4981 email("Hi, I am having problems...");
4982 }
4983 Send patch file to the U-Boot email list;
4984 if (reasonable critiques)
4985 Incorporate improvements from email list code review;
4986 else
4987 Defend code as written;
4988 }
4989
4990 return 0;
4991 }
4992
4993 void no_more_time (int sig)
4994 {
4995 hire_a_guru();
4996 }
4997
4998
4999 Coding Standards:
5000 -----------------
5001
5002 All contributions to U-Boot should conform to the Linux kernel
5003 coding style; see the kernel coding style guide at
5004 https://www.kernel.org/doc/html/latest/process/coding-style.html, and the
5005 script "scripts/Lindent" in your Linux kernel source directory.
5006
5007 Source files originating from a different project (for example the
5008 MTD subsystem) are generally exempt from these guidelines and are not
5009 reformatted to ease subsequent migration to newer versions of those
5010 sources.
5011
5012 Please note that U-Boot is implemented in C (and to some small parts in
5013 Assembler); no C++ is used, so please do not use C++ style comments (//)
5014 in your code.
5015
5016 Please also stick to the following formatting rules:
5017 - remove any trailing white space
5018 - use TAB characters for indentation and vertical alignment, not spaces
5019 - make sure NOT to use DOS '\r\n' line feeds
5020 - do not add more than 2 consecutive empty lines to source files
5021 - do not add trailing empty lines to source files
5022
5023 Submissions which do not conform to the standards may be returned
5024 with a request to reformat the changes.
5025
5026
5027 Submitting Patches:
5028 -------------------
5029
5030 Since the number of patches for U-Boot is growing, we need to
5031 establish some rules. Submissions which do not conform to these rules
5032 may be rejected, even when they contain important and valuable stuff.
5033
5034 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
5035
5036 Patches shall be sent to the u-boot mailing list <u-boot (a] lists.denx.de>;
5037 see https://lists.denx.de/listinfo/u-boot
5038
5039 When you send a patch, please include the following information with
5040 it:
5041
5042 * For bug fixes: a description of the bug and how your patch fixes
5043 this bug. Please try to include a way of demonstrating that the
5044 patch actually fixes something.
5045
5046 * For new features: a description of the feature and your
5047 implementation.
5048
5049 * A CHANGELOG entry as plaintext (separate from the patch)
5050
5051 * For major contributions, add a MAINTAINERS file with your
5052 information and associated file and directory references.
5053
5054 * When you add support for a new board, don't forget to add a
5055 maintainer e-mail address to the boards.cfg file, too.
5056
5057 * If your patch adds new configuration options, don't forget to
5058 document these in the README file.
5059
5060 * The patch itself. If you are using git (which is *strongly*
5061 recommended) you can easily generate the patch using the
5062 "git format-patch". If you then use "git send-email" to send it to
5063 the U-Boot mailing list, you will avoid most of the common problems
5064 with some other mail clients.
5065
5066 If you cannot use git, use "diff -purN OLD NEW". If your version of
5067 diff does not support these options, then get the latest version of
5068 GNU diff.
5069
5070 The current directory when running this command shall be the parent
5071 directory of the U-Boot source tree (i. e. please make sure that
5072 your patch includes sufficient directory information for the
5073 affected files).
5074
5075 We prefer patches as plain text. MIME attachments are discouraged,
5076 and compressed attachments must not be used.
5077
5078 * If one logical set of modifications affects or creates several
5079 files, all these changes shall be submitted in a SINGLE patch file.
5080
5081 * Changesets that contain different, unrelated modifications shall be
5082 submitted as SEPARATE patches, one patch per changeset.
5083
5084
5085 Notes:
5086
5087 * Before sending the patch, run the buildman script on your patched
5088 source tree and make sure that no errors or warnings are reported
5089 for any of the boards.
5090
5091 * Keep your modifications to the necessary minimum: A patch
5092 containing several unrelated changes or arbitrary reformats will be
5093 returned with a request to re-formatting / split it.
5094
5095 * If you modify existing code, make sure that your new code does not
5096 add to the memory footprint of the code ;-) Small is beautiful!
5097 When adding new features, these should compile conditionally only
5098 (using #ifdef), and the resulting code with the new feature
5099 disabled must not need more memory than the old code without your
5100 modification.
5101
5102 * Remember that there is a size limit of 100 kB per message on the
5103 u-boot mailing list. Bigger patches will be moderated. If they are
5104 reasonable and not too big, they will be acknowledged. But patches
5105 bigger than the size limit should be avoided.
5106