doc/README.nios2

   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!