M2-Planet VS live-bootstrap

stage0-posix just gained initial support for RISC-V (64-bit). It starts with 392 byte hex assembler, 361 byte "shell" and bootstraps simple linker (hex2), macro assembler (M0). Then it builds cc_riscv64 RISC-V compiler written in RISC-V assembly and uses it to build simple C compiler written in C (M2-Planet). Then it builds a few extra utilities (cp, mkdir, untar, ungz, sha256sum, chmod)

Not using this, but tangentially related is (full disclosure, i am a maintainer of this project) live-bootstrap, which uses about a KB of binary to do a full "Linux from scratch" style thing - read https://github.com/fosslinux/live-bootstrap/blob/master/part... for all 143 steps you have to go through to get there.

Actually you can skip a file system entirely if you do something like stage0 or live-bootstrap https://github.com/fosslinux/live-bootstrap

See https://github.com/fosslinux/live-bootstrap, and https://github.com/fosslinux/live-bootstrap/blob/master/parts.rst has all the steps we take.

live-bootstrap builds a variety of intermediate systems, starting from a <1KB binary seed (kernel excluded). Check parts.rst for a description, it's kinda wild just how many C and C subset compilers get compiled... but the end result is a system with musl and GCC 4.7, from which building the latest GCC is 2 steps away.

There is also live-bootstrap which uses a similar bootstrap chain to Guix (stage0 -> Mes -> tcc -> gcc), but without needing Guile/guix-daemon binaries etc. The whole thing starts with just a 357-byte binary seed (source)!

There's some cool stuff being done in this area. For example, live-bootstrap goes from a tiny, auditable binary seed to a full GNU userland using only source code (and a Linux kernel).