Bootstrappable builds:

• Guix project reduced binary bootstrap seed size to 357-bytes.
• live-bootstrap project removed the need for an existing kernel.
• Started in 2020 by Samuel Tyler, with co-maintainers and 17 contributors.
• Goal is to create a usable system with human-auditable and written source code.
• Incorporates various bootstrapping tools and historical software versions.

The process:

• Clone Git repository or download release tarball. Use recursive clone for submodules.
• rootfs.py tool can be used for different builds (chroot, QEMU, bare metal).
• Optional to use rootfs.py; instructions for building bare-metal disk image by hand.
• Download release tarballs with./download-distfiles.sh.
• Assemble Builder-Hex0 minimal kernel and concatenate files.

A minimal kernel:

• Builder-Hex0 is a 32-bit minimal kernel by Rick Masters.
• Bootloader reads sources, assembles, and jumps to kernel.
• Kernel has a built-in shell to interpret a shell script.

Toward a larger kernel:

• Build stage0-posix, then Mes (Scheme interpreter and C compiler).
• Mes builds Tiny C Compiler (tcc), which builds Fiwix (OS kernel).
• Fiwix supports various features.

A chain of legacy software:

• Build older versions of open-source projects until GCC.
• Complex process includes building musl and other tools.

Overall:

• The process takes a long time and CPU.
• Removing the Linux kernel lays to rest trust concerns.
• Bootstrappable builds give users confidence in packages.
• They simplify building Linux distributions and ensure software longevity.