ekaitz-zarraga / commencement.scm

Some Guix commencement work for RISC-V

RISC-V commencement

This commencement.scm describes a bootstrapping path for RISC-V for Guix.

It was started from the gnu/packages/commencement.scm file from Guix, but in order to make it work for RISC-V many packages have been replaced, and the bootstrapping path has been heavily edited.

Main differences

There are several differences with the current Guix bootstrap process that have to be taken in account when merging in upstream Guix.

• This new path introduces musl as the glibc versions that can be built with the early compilers we have available don't support RISC-V.

• The GCC-4 used in the project was forked from GCC 4.6.4 and RISC-V support was ported to it. The project is accessible here.

• The file does not describe a full bootstrap process, but enough to reach a modern GCC, which should be able to build the world later.

• The first steps in the process have been already merged in Guix's core-updates branch. This part is split in two different make packages for RISC-V and x86. After it was decided to continue only with RISC-V as the path diverged too much to keep them both in this file.

Current issues

• The bootstrapping path is not compatible with x86, arm or other arches yet ¹.

• gash is removed from the bootstrapping path temporarily (see TODO's in the file) because a bug hangs the process. It is reported upstream.

• flex and bison are not bootstrapped yet as they require some extra work².

• The final GCC package does not support C++ yet, as it requires extra work for Guix compatibility (mostly configure paths), but has been proven to work manually in live-bootstrap.

How to run

guix build -L . -e '(@@ (commencement) gcc-muslboot-9)' --no-grafts --system=riscv64-linux -K

Should build the whole bootstrap chain until a GCC-9.

Related projects

• Live-bootstrap: https://github.com/fosslinux/live-bootstrap

Footnotes

1. There are efforts for including x86 support in this bootstrapping path. See https://gitlab.com/janneke/commencement.scm.git ↩

2. They have been manually bootstrapped in live-bootstrap, so this work is doable. ↩