From 862f9928aae1684b0aff55b42de09c1156d0f399 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Thu, 18 Jul 2019 00:34:29 -0700 Subject: doc: arch: Convert README.nios2 to reST Convert plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Bin Meng --- doc/arch/index.rst | 1 + doc/arch/nios2.rst | 111 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 112 insertions(+) create mode 100644 doc/arch/nios2.rst (limited to 'doc/arch') diff --git a/doc/arch/index.rst b/doc/arch/index.rst index 7f10df08f3..000f5de634 100644 --- a/doc/arch/index.rst +++ b/doc/arch/index.rst @@ -9,4 +9,5 @@ Architecture-specific doc arm64 mips nds32 + nios2 x86 diff --git a/doc/arch/nios2.rst b/doc/arch/nios2.rst new file mode 100644 index 0000000000..35defb0af0 --- /dev/null +++ b/doc/arch/nios2.rst @@ -0,0 +1,111 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +Nios II +======= + +Nios II is a 32-bit embedded-processor architecture designed +specifically for the Altera family of FPGAs. + +Please refer to the link for more information on Nios II: +https://www.altera.com/products/processors/overview.html + +Please refer to the link for Linux port and toolchains: +http://rocketboards.org/foswiki/view/Documentation/NiosIILinuxUserManual + +The Nios II port of u-boot is controlled by device tree. Please check +out doc/README.fdt-control. + +To add a new board/configuration (eg, mysystem) to u-boot, you will need +three files. + +1. The device tree source which describes the hardware, dts file: + arch/nios2/dts/mysystem.dts + +2. Default configuration of Kconfig, defconfig file: + configs/mysystem_defconfig + +3. The legacy board header file: + include/configs/mysystem.h + +The device tree source must be generated from your qsys/sopc design +using the sopc2dts tool. Then modified to fit your configuration. + +Please find the sopc2dts download and usage at the wiki: +http://www.alterawiki.com/wiki/Sopc2dts + +.. code-block:: none + + $ java -jar sopc2dts.jar --force-altr -i mysystem.sopcinfo -o mysystem.dts + +You will need to add additional properties to the dts. Please find an +example at, arch/nios2/dts/10m50_devboard.dts. + +1. Add "stdout-path=..." property with your serial path to the chosen + node, like this:: + + chosen { + stdout-path = &uart_0; + }; + +2. If you use SPI/EPCS or I2C, you will need to add aliases to number + the sequence of these devices, like this:: + + aliases { + spi0 = &epcs_controller; + }; + +Next, you will need a default config file. You may start with +10m50_defconfig, modify the options and save it. + +.. code-block:: none + + $ make 10m50_defconfig + $ make menuconfig + $ make savedefconfig + $ cp defconfig configs/mysystem_defconfig + +You will need to change the names of board header file and device tree, +and select the drivers with menuconfig. + +.. code-block:: none + + Nios II architecture ---> + (mysystem) Board header file + Device Tree Control ---> + (mysystem) Default Device Tree for DT control + +There is a selection of "Provider of DTB for DT control" in the Device +Tree Control menu. + + * Separate DTB for DT control, will cat the dtb to end of u-boot + binary, output u-boot-dtb.bin. This should be used for production. + If you use boot copier, like EPCS boot copier, make sure the copier + copies all the u-boot-dtb.bin, not just u-boot.bin. + + * Embedded DTB for DT control, will include the dtb inside the u-boot + binary. This is handy for development, eg, using gdb or nios2-download. + +The last thing, legacy board header file describes those config options +not covered in Kconfig yet. You may copy it from 10m50_devboard.h:: + + $ cp include/configs/10m50_devboard.h include/configs/mysystem.h + +Please change the SDRAM base and size to match your board. The base +should be cached virtual address, for Nios II with MMU it is 0xCxxx_xxxx +to 0xDxxx_xxxx. + +.. code-block:: c + + #define CONFIG_SYS_SDRAM_BASE 0xc8000000 + #define CONFIG_SYS_SDRAM_SIZE 0x08000000 + +You will need to change the environment variables location and setting, +too. You may change other configs to fit your board. + +After all these changes, you may build and test:: + + $ export CROSS_COMPILE=nios2-elf- (or nios2-linux-gnu-) + $ make mysystem_defconfig + $ make + +Enjoy! -- cgit v1.2.3