Radiance Kernels

This WIP repo is based off of virgo-kernels.

Setup

You will need a GCC rv32 toolchain installed from riscv-gnu-toolchain. You might need to set ABI to be ilp32 (not ilp32d). Export that path to an environment variable $(RISCV_TOOLCHAIN_PATH) - there should be a directory called riscv32-unknown-elf under that path. The purpose of this installation is to retrieve headers & definitions from the GCC sysroot; the binary libraries are not usable and no libraries (e.g. libm, crt) can be linked to due to ISA differences.

There are two ways to install the Muon LLVM toolchain.

• Prebuilt: run ./scripts/llvm_prebuilt.sh, which will decompress the existing archived LLVM binaries at llvm/llvm-muon.tar.xz. This is compiled on an Ubuntu 24.04 system with GLIBC 2.39, meaning there's a good chance it won't work on older systems. You will also need ZSTD. If for any reason the prebuilt toolchain doesn't work, use the second method.

• Build from scratch: run ./scripts/llvm.sh. This will initialize the submodule located at llvm/llvm-src, which is not cloned by default due to its size. You will need clang, clang++, ninja installed in your system (more may be required) to build the Muon toolchain.

Once the toolchain is installed, compile the Muon runtime by running make under lib/. There should now be lib/libmuonrt.a; if not, check previous steps. As a further compiler sanity check, you can also inspect for any <unknown>s in the assembly dump lib/libmuonrt.dump; all instructions in executable sections should be 8 bytes and properly recognized by the disassembler.

Run ISA Tests

First initialize the submodule:

git submodule update --init muon-isa-tests

Then compile the tests:

autoconf
./configure
cd isa
make

This should generate a bunch of binaries under isa along with their dumps. You can run the tests with cyclotron, or straight from the isa directory by using make run. Note that you'll need to go into isa/Makefile and change the MUON_SIM variable to point to the compiled cyclotron binary.

Run Kernels

Similar to the ISA tests, go to kernels/<kernel_name> and run make. The output kernel.radiance.elf is what you want.