> If your package manager does not provide the RISC-V GNU toolchain you can either download the binaries from the [xPack GNU RISC-V Embedded GCC](https://github.com/xpack-dev-tools/riscv-none-elf-gcc-xpack/releases) package or it can be compiled from their [main repository](https://github.com/riscv-collab/riscv-gnu-toolchain). Also you can take a look to the [docker enviroment](#docker-enviroment) provided.
To set up the enviroment you can create a [dev enviroment](https://docs.docker.com/desktop/dev-environments) pointing to this repository or you can pull the image directly from the container registry and then run it:
To build the firmware that will be loaded in the instruction memory and the simulation testbenchs execute CMake in the project root directory using your system default toolchain (the [CMake toolchain file](cmake/riscv-toolchain.cmake) will search automatically for a RISC-V toolchain to build the firmware).
This will generate a `sandbox.mem` file in the `/build/fw/sandbox` folder. For other simualtors than verilator make sure to add the firmware it to your simulator sources and that the memory path matches the path specified in the memory module.
For experimenting with a custom firmware, configure the project with one from the following options and use the examples in the [sandbox](fw/sandbox) folder.