1 Nios II is a 32-bit embedded-processor architecture designed 2 specifically for the Altera family of FPGAs. 3 4 Please refer to the link for more information on Nios II, 5 https://www.altera.com/products/processors/overview.html 6 7 Please refer to the link for Linux port and toolchains, 8 http://rocketboards.org/foswiki/view/Documentation/NiosIILinuxUserManual 9 10 The Nios II port of u-boot is controlled by device tree. Please check 11 out doc/README.fdt-control. 12 13 To add a new board/configuration (eg, mysystem) to u-boot, you will need 14 three files. 15 16 1. The device tree source which describes the hardware, dts file. 17 arch/nios2/dts/mysystem.dts 18 19 2. Default configuration of Kconfig, defconfig file. 20 configs/mysystem_defconfig 21 22 3. The legacy board header file. 23 include/configs/mysystem.h 24 25 The device tree source must be generated from your qsys/sopc design 26 using the sopc2dts tool. Then modified to fit your configuration. Please 27 find the sopc2dts download and usage at the wiki, 28 http://www.alterawiki.com/wiki/Sopc2dts 29 30 $ java -jar sopc2dts.jar --force-altr -i mysystem.sopcinfo -o mysystem.dts 31 32 You will need to add additional properties to the dts. Please find an 33 example at, arch/nios2/dts/10m50_devboard.dts. 34 35 1. Add "stdout-path=..." property with your serial path to the chosen 36 node, like this, 37 chosen { 38 stdout-path = &uart_0; 39 }; 40 41 2. If you use SPI/EPCS or I2C, you will need to add aliases to number 42 the sequence of these devices, like this, 43 aliases { 44 spi0 = &epcs_controller; 45 }; 46 47 Next, you will need a default config file. You may start with 48 10m50_defconfig, modify the options and save it. 49 50 $ make 10m50_defconfig 51 $ make menuconfig 52 $ make savedefconfig 53 $ cp defconfig configs/mysystem_defconfig 54 55 You will need to change the names of board header file and device tree, 56 and select the drivers with menuconfig. 57 58 Nios II architecture ---> 59 (mysystem) Board header file 60 Device Tree Control ---> 61 (mysystem) Default Device Tree for DT control 62 63 There is a selection of "Provider of DTB for DT control" in the Device 64 Tree Control menu. 65 66 ( ) Separate DTB for DT control, will cat the dtb to end of u-boot 67 binary, output u-boot-dtb.bin. This should be used for production. 68 If you use boot copier, like EPCS boot copier, make sure the copier 69 copies all the u-boot-dtb.bin, not just u-boot.bin. 70 71 ( ) Embedded DTB for DT control, will include the dtb inside the u-boot 72 binary. This is handy for development, eg, using gdb or nios2-download. 73 74 The last thing, legacy board header file describes those config options 75 not covered in Kconfig yet. You may copy it from 10m50_devboard.h. 76 77 $ cp include/configs/10m50_devboard.h include/configs/mysystem.h 78 79 Please change the SDRAM base and size to match your board. The base 80 should be cached virtual address, for Nios II with MMU it is 0xCxxx_xxxx 81 to 0xDxxx_xxxx. 82 83 #define CONFIG_SYS_SDRAM_BASE 0xc8000000 84 #define CONFIG_SYS_SDRAM_SIZE 0x08000000 85 86 You will need to change the environment variables location and setting, 87 too. You may change other configs to fit your board. 88 89 After all these changes, you may build and test. 90 91 $ export CROSS_COMPILE=nios2-elf- (or nios2-linux-gnu-) 92 $ make mysystem_defconfig 93 $ make 94 95 Enjoy! 96
