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 elf multilib toolchain
• A GCC linux multilib toolchain, with linux user-space Qemu binaries

How to do a release

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

   • CROSSTOOL_NG_VERSION in install-crosstool-ng.sh
   • QEMU_VERSION in build-gcc-with-args.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 pipeline to complete.

   The build can be tested by downloading the Azure Pipeline artifacts.

   1. Go to the lowrisc-toolchains Azure Pipelines page
   2. Select a build
   3. Click on "Artifacts" (top right)
   4. Download the desired artifact, 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 Azure Pipelines, and the resulting binaries will be uploaded to GitHub releases.

How to generate the bitmanip patches

1. Generate the binutils patch:

   git clone https://github.com/riscv/riscv-binutils-gdb.git
   cd riscv-binutils-gdb
   git checkout riscv-bitmanip
   # 612aac65 is our upstream baseline
   git diff 612aac65 > $TOP/patches/binutils/git-612aac65/001-bitmanip.patch
   

2. Generate the GCC patch:

   git clone https://github.com/riscv/riscv-gcc.git
   cd riscv-gcc
   git checkout riscv-bitmanip
   # 49f75e008c0 is our upstream baseline
   git diff 49f75e008c0 > $TOP/patches/gcc/git-49f75e00/001-bitmanip.patch