1.. SPDX-License-Identifier: GPL-2.0+ 2 3Nios II 4======= 5 6Nios II is a 32-bit embedded-processor architecture designed 7specifically for the Altera family of FPGAs. 8 9Please refer to the link for more information on Nios II: 10https://www.altera.com/products/processors/overview.html 11 12Please refer to the link for Linux port and toolchains: 13http://rocketboards.org/foswiki/view/Documentation/NiosIILinuxUserManual 14 15The Nios II port of u-boot is controlled by device tree. Please check 16out doc/README.fdt-control. 17 18To add a new board/configuration (eg, mysystem) to u-boot, you will need 19three files. 20 211. The device tree source which describes the hardware, dts file: 22 arch/nios2/dts/mysystem.dts 23 242. Default configuration of Kconfig, defconfig file: 25 configs/mysystem_defconfig 26 273. The legacy board header file: 28 include/configs/mysystem.h 29 30The device tree source must be generated from your qsys/sopc design 31using the sopc2dts tool. Then modified to fit your configuration. 32 33Please find the sopc2dts download and usage at the wiki: 34http://www.alterawiki.com/wiki/Sopc2dts 35 36.. code-block:: none 37 38 $ java -jar sopc2dts.jar --force-altr -i mysystem.sopcinfo -o mysystem.dts 39 40You will need to add additional properties to the dts. Please find an 41example at, arch/nios2/dts/10m50_devboard.dts. 42 431. Add "stdout-path=..." property with your serial path to the chosen 44 node, like this:: 45 46 chosen { 47 stdout-path = &uart_0; 48 }; 49 502. If you use SPI/EPCS or I2C, you will need to add aliases to number 51 the sequence of these devices, like this:: 52 53 aliases { 54 spi0 = &epcs_controller; 55 }; 56 57Next, you will need a default config file. You may start with 5810m50_defconfig, modify the options and save it. 59 60.. code-block:: none 61 62 $ make 10m50_defconfig 63 $ make menuconfig 64 $ make savedefconfig 65 $ cp defconfig configs/mysystem_defconfig 66 67You will need to change the names of board header file and device tree, 68and select the drivers with menuconfig. 69 70.. code-block:: none 71 72 Nios II architecture ---> 73 (mysystem) Board header file 74 Device Tree Control ---> 75 (mysystem) Default Device Tree for DT control 76 77There is a selection of "Provider of DTB for DT control" in the Device 78Tree Control menu. 79 80 * Separate DTB for DT control, will cat the dtb to end of u-boot 81 binary, output u-boot-dtb.bin. This should be used for production. 82 If you use boot copier, like EPCS boot copier, make sure the copier 83 copies all the u-boot-dtb.bin, not just u-boot.bin. 84 85 * Embedded DTB for DT control, will include the dtb inside the u-boot 86 binary. This is handy for development, eg, using gdb or nios2-download. 87 88The last thing, legacy board header file describes those config options 89not covered in Kconfig yet. You may copy it from 10m50_devboard.h:: 90 91 $ cp include/configs/10m50_devboard.h include/configs/mysystem.h 92 93Please change the SDRAM base and size to match your board. The base 94should be cached virtual address, for Nios II with MMU it is 0xCxxx_xxxx 95to 0xDxxx_xxxx. 96 97.. code-block:: c 98 99 #define CONFIG_SYS_SDRAM_BASE 0xc8000000 100 #define CONFIG_SYS_SDRAM_SIZE 0x08000000 101 102You will need to change the environment variables location and setting, 103too. You may change other configs to fit your board. 104 105After all these changes, you may build and test:: 106 107 $ export CROSS_COMPILE=nios2-elf- (or nios2-linux-gnu-) 108 $ make mysystem_defconfig 109 $ make 110 111Enjoy! 112