How to add other boards?

[DuyTrandeLion]

Hello, I would like to add other boards lile Pynq-Z1 and Ultra96. Do you have any guides for this?

[mwrnd]

I am in the process of adding a new board to vivado-risc-v. Look at this comparison of my branch and the official branch for the changes I have made thus far. I also started on some notes.

First step is to create a Github fork of vivado-risc-v. Copy one of the directories under board that is closest to your target board and rename it. Edit board/YOURBOARNAME/Makefile.inc to the specifics of your board. XilinxBoardStore has support for the Ultra96 and some PYNQ boards. If your board does not have an official repo, you can set BOARD_PART=NONE which is now an option.

Edit board/YOURBOARNAME/bootrom.dts to add peripherals to a compiled RISC-V. Ideally you would choose a board to copy that has an identical peripheral set and bootrom.dts does not need editing.

You may leave the default frequencies in board/rocket-freq.

Edit ethernet.xdc, sdc.xdc, top.xdc, and uart.xdc with the pins of your board.

source your Vivado's settings in a Terminal and compile a RISC-V project for your customized board. Note that you will need about 20GB of free drive space. make will download about 8GB of files on a first compile.

source /opt/Xilinx/Vivado/2022.1/settings64.sh
make CONFIG=rocket64b2 BOARD=YOURBOARNAME vivado-tcl

If all goes well you will end up with a project under the workspace directory that includes a .tcl file you can source in Vivado.

Open the Block Design for editing and make any necessary changes. Then write a new project TCL file and use the resulting file as board/YOURBOARNAME/riscv-202?.?.tcl

It is also useful to compile a project for one of the supported boards to see what happens.

[DuyTrandeLion]

Hi @mwrnd , I successfully built for the Arty-A7-100 board which does not have an SD Card slot. May I ask where the code is stored and how should I write a Hello World C program for it? Thanks.

[mwrnd]

I do not have an Arty but you should be able to upload and run the bare-metal demo using the on-board USB-JTAG. The output of the demo will go to the on-board USB-UART.

Compile the hello-world demo and then disassemble it for easier debug.

cd vivado-risc-v/bare-metal/hello-world
make
riscv64-unknown-elf-objdump -S -l --inlines -D boot.elf  > boot_elf_dis.txt

In one terminal:

source /tools/Xilinx/Vivado/[VIVADO_VERSION]/settings64.sh
xsdb

connect
targets
targets 3
stop
dow  vivado-risc-v/bare-metal/hello-world/boot.elf
con
rrd
rr pc

In a second terminal, run sudo gtkterm --port /dev/ttyUSB0 to view the output of the bare-metal demo. Again, I do not have an Arty so I am guessing that its USB-UART will show up as /dev/ttyUSB0. From this thread it appears the USB-UART may show up as /dev/ttyUSB1. Try ls -l /dev | grep ttyUSB to see all USB-UART devices.

A picture of a similar task:

[DuyTrandeLion]

After getting the CTSn pin to constant 0, I got the example working. I think the same method should be applied for RSTn, is it right?
Last question: Can I contribute the Arty-A7 project to this repo? If yes, do you need the include the SD Card to the design and require an external pmod to micro sdcard module to run Linux?

[mwrnd]

RTSn is an output from the UART and can be left floating. The Arty-A7 only uses the RX and TX pins.

As for contributing, wait for @eugene-tarassov to respond but please fork the repo either way in case other Arty-A7 users want to give it a go. Please mention the Arty-A7 in the About description so it is easier to search for on GitHub.

Note that @eugene-tarassov mentioned in a previous post about having a "fully automated build and test system running continuously with multiple target boards". Adding another board may be too much of a support hassle.

[eugene-tarassov]

Can I contribute the Arty-A7 project to this repo?

Yes. It would be nice. The recommended way is to fork the repo and create pull request.

do you need the include the SD Card to the design

I would prefer the SD card controller included, and Linux supported with SD card pmod, but it is not required.

[eugene-tarassov]

I have not heard from you for a while, so I have added support for Arty A7 100T

[DuyTrandeLion]

Hi Eugene, I was stuck with the MII interface. It looks like you have added it... Sorry I did not make it in time.