Introduction

This is a test repository to run the amaranth-spacewire core in a LiteX SoC.

Documentation regarding the amaranth-spacewire core can be found in its repository.

Requirements

LiteX

Refer to the install instructions in the LiteX repository.

Toolchain

The FPGA toolchain for your board vendor.

Amaranth HDL

Amaranth HDL.

RISC-V toolchain

A RISC-V toolchain. It can be installed at the same time that you install LiteX.

Installing litex-amaranth-spacewire

$ git submodule update --init --recursive
$ cd litex-amaranth-spacewire && python setup.py develop --user && cd ..

Building and loading

Terasic de0nano

1. Add the RISCV toolchain and the FPGA toolchain to the PATH

$ export PATH=/path/to/toolchain/riscv64-unknown-elf-gcc-xxxx/bin:$PATH
$ export PATH=/path/to/toolchain/XX.X/quartus/bin
$ export QUARTUS_ROOTDIR=/path/to/toolchain/XX.X/quartus/bin

2. Build the bitstream

$ python make.py --board de0nano --build`

SiPeed tangnano4k

1. Add the RISCV toolchain and the FPGA toolchain to the PATH

$ export PATH=/path/to/toolchain/riscv64-unknown-elf-gcc-xxxx/bin:$PATH
$ export PATH=/path/to/toolchain/IDE/bin:$PATH

2. Build the bitstream

$ python make.py --board tangnano4k --build --rx-tokens 4 --tx-tokens 4

The --rx-tokens and --tx-tokens flags are added to correctly fit the design in the FPGA.

SiPeed tangnano9k

1. Add the RISCV toolchain and the FPGA toolchain to the PATH

$ export PATH=/path/to/toolchain/riscv64-unknown-elf-gcc-xxxx/bin:$PATH
$ export PATH=/path/to/toolchain/IDE/bin:$PATH

2. Build the bitstream

$ python make.py --board tangnano9k --build

Building the demo app

Note: The C demo is deprecated in favor of the Rust application.

The demo app will activate the SpaceWire IP and show the link status. It can be found under the app directory.

In order to be built you need to add the RISCV toolchain to the path, and export the BUILD_DIR variable. Assuming that this repository is placed in REPO_PATH, and that you built for the board BOARD, then you should:

$ export BUILD_DIR=REPO_PATH/build/BOARD

C application

Then run make in the app-c directory. This will generate the spw_app.bin binary. It can be uploaded to your board with litex_term with the following command:

$ litex_term --kernel=spw_app.bin --serial-boot {SERIALPORT}

Rust application

To build the rust application you must first build the target for your board (see above). Then you can run cargo build in the app-rs directory or execute one of the make targets available (e.g. make tangnano9k_app.

Executing the application (loading it to the target) can be done running the cargo run -- /dev/ttyUSBX command from the app-rs directory.

Note: You may need to adjust the SYSTEM_CLOCK_FREQUENCY constant to match your target.

Troubleshooting

undefined symbol: FT_Done_MM_Var

If you hit the error

Error gw_sh: symbol lookup error: /usr/lib/libfontconfig.so.1: undefined symbol: FT_Done_MM_Var

you can try prefixing the build command with LD_PRELOAD=/usr/lib/libfreetype.so.