Installing prerequisites

1 Installing LiteX and Toolchain

This section focuses on the core configuration required to build the SoC in use. A more comprehensive walkthrough of the installation process can be found on LiteX’s github page.

1.1 Make an empty directory and install the Litex files

The following commands install litex in a directory of your choice:

$ mkdir litex && cd litex
$ wget https://raw.githubusercontent.com/enjoy-digital/litex/master/litex_setup.py
$ chmod +x litex_setup.py
$ ./litex_setup.py --init --install

If you wish to install to your user directory, you can call $ ./litex_setup.py --init --install --user instead.

Installing to a virtual environment is also possible:

$ mkdir litex && cd litex
$ virtualenv -p python3 venv_litex
$ source venv_litex/bin/activate 
$ wget https://raw.githubusercontent.com/enjoy-digital/litex/master/litex_setup.py
$ chmod +x litex_setup.py
$ ./litex_setup.py --init --install

1.2 Installing Toolchain

The Risc-V toolchain can also be installed with Litex. To do that simply call:

$ pip3 install meson ninja
$ ./litex_setup.py --gcc=riscv

The toolchain will be installed to a subdirectory in the litex directory and will be titled riscv64-unknown-elf-gcc-8.3.0-2019.08.0-x86_64-linux-ubuntu14

To enable the toolchain, add it to your path:

$ export PATH="/PATH_TO_INSTALLATION/riscv64-unknown-elf-gcc-8.3.0-2019.08.0-x86_64-linux-ubuntu14/bin/:$PATH"
$ source .bashrc

Note the command above only adds the toolchain to the path for the current terminal session. In order add the toolcahin to the path permanently, append the same line to .bashrc.

2. Installing Synthesis Tools

2.1 Installing project Icestorm (Lattice FPGA)

Lattice Semiconductors have their own propiertary software for synthesising and configuring their FPGAS, however there are also open source tools that can be used. Project Icestorm is a mature and well doucumented open source tool that is used. Installiation steps can be found on the website linked, and a summary of the necessary steps is given here. The tools needed are Yosys, Arachne-PNR and Icestorm. Once installed, you can look at a nice and concise guide on using the tools, found here.

2.1.1 Intalling Icestorm

The repository needs to be cloned and installed:

$ git clone https://github.com/YosysHQ/icestorm.git icestorm
$ cd icestorm
$ make -j$(nproc)
$ sudo make install

2.1.2 Installing NEXT-PNR

$ git clone https://github.com/YosysHQ/nextpnr nextpnr
$ cd nextpnr
$ cmake -DARCH=ice40 -DCMAKE_INSTALL_PREFIX=/usr/local .
$ make -j$(nproc)
$ sudo make install

2.1.3 Installing Yosys

$ git clone https://github.com/YosysHQ/yosys.git yosys
$ cd yosys
$ make -j$(nproc)
$ sudo make install

2.1.4 Creating UDEV Rules

On Linux machines, if you have an error configuring the fpga, you’d need to create the udev rules to allow your user account to connect to the development board using iceprog. In order to do that, run the following commands:

$ touch /etc/udev/rules.d/53-lattice-ftdi.rules
$ sudo nano /etc/udev/rules.d/53-lattice-ftdi.rules

When inside the file, add the following text:

ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6010", MODE="0660", GROUP="plugdev", TAG+="uaccess"

2.1 Installing Vivado (Xilinx FPGA)

Vivado is a large download and may take hours on slow/unreliable internet connections. The download process can be found here. The latest version can be installed, however please note this project has only been tested with version 2021.2.