1 Summary 2 ======= 3 The README is for the boot procedure on the ipam390 board 4 5 In the context of U-Boot, the board is booted in three stages. The initial 6 bootloader which executes upon reset is the ROM Boot Loader (RBL) and sits 7 in the internal ROM. The RBL initializes the internal memory and then 8 depending on the exact board and pin configurations will initialize another 9 controller (such as NAND) to continue the boot process by loading 10 the secondary program loader (SPL). The SPL will initialize the system 11 further (some clocks, SDRAM). As on this board is used the falcon boot 12 mode, now 2 ways are possible depending on the GPIO 7_14 input pin, 13 connected with the "soft reset switch" 14 15 If this pin is logical 1 (high level): 16 spl code starts the kernel image without delay 17 18 If this pin is logical 0 (low level): 19 spl code starts the u-boot image 20 21 AIS is an image format defined by TI for the images that are to be loaded 22 to memory by the RBL. The image is divided into a series of sections and 23 the image's entry point is specified. Each section comes with meta data 24 like the target address the section is to be copied to and the size of the 25 section, which is used by the RBL to load the image. At the end of the 26 image the RBL jumps to the image entry point. The AIS format allows for 27 other things such as programming the clocks and SDRAM if the header is 28 programmed for it. We do not take advantage of this and instead use SPL as 29 it allows for additional flexibility (run-time detect of board revision, 30 loading the next image from a different media, etc). 31 32 Compilation 33 =========== 34 run "tools/buildman/buildman -k ipam390" in the u-boot source tree. 35 Once this build completes you will have a ../current/ipam390/u-boot.ais file 36 that needs to be written to the nand flash. 37 38 Flashing the images to NAND 39 ========================== 40 The AIS image can be written to NAND flash using the following commands. 41 Assuming that the network is configured and enabled and the u-boot.ais file 42 is tftp'able. 43 44 U-Boot > print upd_uboot 45 upd_uboot=tftp c0000000 ${u-boot};nand erase.part u-boot;nand write c0000000 20000 ${filesize} 46 U-Boot > 47 U-Boot > run upd_uboot 48 Using DaVinci-EMAC device 49 TFTP from server 192.168.1.1; our IP address is 192.168.20.71 50 Filename '/tftpboot/ipam390/u-boot.ais'. 51 Load address: 0xc0000000 52 Loading: ################################## 53 1.5 MiB/s 54 done 55 Bytes transferred = 493716 (78894 hex) 56 57 NAND erase.part: device 0 offset 0x20000, size 0x160000 58 Erasing at 0x160000 -- 100% complete. 59 OK 60 61 NAND write: device 0 offset 0x20000, size 0x78894 62 493716 bytes written: OK 63 U-Boot > 64 65 Recovery 66 ======== 67 68 In the case of a "bricked" board, you need to use the TI tools found 69 here[1] to create an uboot-uart-ais.bin file 70 71 - cd to the u-boot source tree 72 73 - compile the u-boot for the ipam390 board: 74 $ tools/buildman/buildman -k ipam390 75 76 -> Now we shall have u-boot.bin 77 78 - Create u-boot-uart-ais.bin 79 $ mono HexAIS_OMAP-L138.exe -entrypoint 0xC1080000 -ini ipam390-ais-uart.cfg \ 80 -o ../current/ipam390/uboot-uart-ais.bin ./u-boot.bin@0xC1080000; 81 82 Note: The ipam390-ais-uart.cfg is found in the board directory 83 for the ipam390 board, u-boot:/board/Barix/ipam390/ipam390-ais-uart.cfg 84 85 - We can now run bootloader on IPAM390 via UART using the command below: 86 87 $ mono ./slh_OMAP-L138.exe -waitForDevice -v -p /dev/tty.UC-232AC uboot-uart-ais.bin 88 NOTE: Do not cancel the command execution! The command takes 20+ seconds 89 to upload u-boot over serial and run it! 90 Outcome: 91 Waiting for the OMAP-L138... 92 (AIS Parse): Read magic word 0x41504954. 93 (AIS Parse): Waiting for BOOTME... (power on or reset target now) 94 (AIS Parse): BOOTME received! 95 (AIS Parse): Performing Start-Word Sync... 96 (AIS Parse): Performing Ping Opcode Sync... 97 (AIS Parse): Processing command 0: 0x5853590D. 98 (AIS Parse): Performing Opcode Sync... 99 (AIS Parse): Executing function... 100 (AIS Parse): Processing command 1: 0x5853590D. 101 (AIS Parse): Performing Opcode Sync... 102 (AIS Parse): Executing function... 103 (AIS Parse): Processing command 2: 0x5853590D. 104 (AIS Parse): Performing Opcode Sync... 105 (AIS Parse): Executing function... 106 (AIS Parse): Processing command 3: 0x5853590D. 107 (AIS Parse): Performing Opcode Sync... 108 (AIS Parse): Executing function... 109 (AIS Parse): Processing command 4: 0x5853590D. 110 (AIS Parse): Performing Opcode Sync... 111 (AIS Parse): Executing function... 112 (AIS Parse): Processing command 5: 0x58535901. 113 (AIS Parse): Performing Opcode Sync... 114 (AIS Parse): Loading section... 115 (AIS Parse): Loaded 326516-Byte section to address 0xC1080000. 116 (AIS Parse): Processing command 6: 0x58535906. 117 (AIS Parse): Performing Opcode Sync... 118 (AIS Parse): Performing jump and close... 119 (AIS Parse): AIS complete. Jump to address 0xC1080000. 120 (AIS Parse): Waiting for DONE... 121 (AIS Parse): Boot completed successfully. 122 123 Operation completed successfully. 124 125 Falcon Bootmode (boot linux without booting U-Boot) 126 =================================================== 127 128 The Falcon Mode extends this way allowing to start the Linux kernel directly 129 from SPL. A new command is added to U-Boot to prepare the parameters that SPL 130 must pass to the kernel, using ATAGS or Device Tree. 131 132 In normal mode, these parameters are generated each time before 133 loading the kernel, passing to Linux the address in memory where 134 the parameters can be read. 135 With Falcon Mode, this snapshot can be saved into persistent storage and SPL is 136 informed to load it before running the kernel. 137 138 To boot the kernel, these steps under a Falcon-aware U-Boot are required: 139 140 1. Boot the board into U-Boot. 141 Use the "spl export" command to generate the kernel parameters area or the DT. 142 U-Boot runs as when it boots the kernel, but stops before passing the control 143 to the kernel. 144 145 Here the command sequence for the ipam390 board: 146 - load the linux kernel image into ram: 147 148 U-Boot > nand read c0100000 2 200000 400000 149 150 NAND read: device 0 offset 0x200000, size 0x400000 151 4194304 bytes read: OK 152 153 - generate the bootparms image: 154 155 U-Boot > spl export atags c0100000 156 ## Booting kernel from Legacy Image at c0100000 ... 157 Image Name: Linux-3.5.1 158 Image Type: ARM Linux Kernel Image (uncompressed) 159 Data Size: 2504280 Bytes = 2.4 MiB 160 Load Address: c0008000 161 Entry Point: c0008000 162 Verifying Checksum ... OK 163 Loading Kernel Image ... OK 164 subcommand not supported 165 subcommand not supported 166 Argument image is now in RAM at: 0xc0000100 167 168 - copy the bootparms image into nand: 169 170 U-Boot > mtdparts 171 172 device nand0 <davinci_nand.0>, # parts = 6 173 #: name size offset mask_flags 174 0: u-boot-env 0x00020000 0x00000000 0 175 1: u-boot 0x00160000 0x00020000 0 176 2: bootparms 0x00020000 0x00180000 0 177 3: factory-info 0x00060000 0x001a0000 0 178 4: kernel 0x00400000 0x00200000 0 179 5: rootfs 0x07a00000 0x00600000 0 180 181 active partition: nand0,0 - (u-boot-env) 0x00020000 @ 0x00000000 182 183 defaults: 184 mtdids : nand0=davinci_nand.0 185 mtdparts: mtdparts=davinci_nand.0:128k(u-boot-env),1408k(u-boot),128k(bootparms),384k(factory-info),4M(kernel),-(rootfs) 186 U-Boot > nand erase.part bootparms 187 188 NAND erase.part: device 0 offset 0x180000, size 0x20000 189 Erasing at 0x180000 -- 100% complete. 190 OK 191 U-Boot > nand write c0000100 180000 20000 192 193 NAND write: device 0 offset 0x180000, size 0x20000 194 131072 bytes written: OK 195 U-Boot > 196 197 You can use also the predefined U-Boot Environment variable "setbootparms", 198 which will do all the above steps in one command: 199 200 U-Boot > print setbootparms 201 setbootparms=nand read c0100000 200000 400000;spl export atags c0100000;nand erase.part bootparms;nand write c0000100 180000 20000 202 U-Boot > run setbootparms 203 204 NAND read: device 0 offset 0x200000, size 0x400000 205 4194304 bytes read: OK 206 ## Booting kernel from Legacy Image at c0100000 ... 207 Image Name: Linux-3.5.1 208 Image Type: ARM Linux Kernel Image (uncompressed) 209 Data Size: 2504280 Bytes = 2.4 MiB 210 Load Address: c0008000 211 Entry Point: c0008000 212 Verifying Checksum ... OK 213 Loading Kernel Image ... OK 214 subcommand not supported 215 subcommand not supported 216 Argument image is now in RAM at: 0xc0000100 217 218 NAND erase.part: device 0 offset 0x180000, size 0x20000 219 Erasing at 0x180000 -- 100% complete. 220 OK 221 222 NAND write: device 0 offset 0x180000, size 0x20000 223 131072 bytes written: OK 224 U-Boot > 225 226 Links 227 ===== 228 [1] 229 http://sourceforge.net/projects/dvflashutils/files/OMAP-L138/ 230
