lowRISC toolchain builds

This repository contains tools to create toolchains for lowRISC internal use. The toolchains are not supported by lowRISC or recommended to be used outside of lowRISC.

Head over to the GitHub releases for this repository for pre-built toolchains.

• A GCC RV32IMC without hardfloat support, targeting Ibex
• A GCC RV64IMAC, targeting Muntjac
• A GCC elf multilib toolchain
• A GCC linux multilib toolchain

How to do a release

1. Modify any of the following variables to configure the build:

   • CROSSTOOL_NG_VERSION in install-crosstool-ng.sh

2. Modify any of the *.config files to update the crosstool-ng configurations for a particular toolchain.

3. Push the changes or do a pull request, and wait for the CI workflow to complete.

   The build can be tested by downloading the GitHub artifacts.

   1. Go to the lowrisc-toolchains Actions page.
   2. Select a workflow run from the list.
   3. Download the desired artifact from the bottom of the page and test it.

4. Tag a release

   VERSION=$(date +%Y%m%d)-1
   git tag -a -m "Release version $VERSION" $VERSION

5. Push the tag

   git push origin $VERSION

   Now the release builds on GitHub's CI, and the resulting binaries will be uploaded to GitHub releases.

How to generate the bitmanip patch

git clone https://github.com/riscv-collab/riscv-binutils-gdb.git
cd riscv-binutils-gdb
# checkout Pirmin's bitmanip 1.00+0.93 PR (https://github.com/riscv-collab/riscv-binutils-gdb/pull/267)
gh pr checkout 267
# 7c9dd840 (riscv-binutils-2.35-rvb) is our baseline
git diff 7c9dd840 > $TOP/patches/lowrisc-toolchain-gcc-rv32imcb/binutils/git-7c9dd840/001-bitmanip.patch

How to install pre-built toolchain

1. Download a tar.gz file from release page.
2. Decompress files to ~/.local

  tar -xf  <location of your tar.gz> --strip-components=1 -C ~/.local

3. Now you should be able to compile software with lowrisc-toolchain.