commit: 2233af5614138e680095ca959e419c6dec74ed19
parent 96f22ce289dab1fcc1b0e14fd9b08ab974c15584
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date: Mon, 8 Sep 2025 02:47:46 +0200
Add rationale between e2fsprogs/genext2fs/lwext4
Diffstat:
| A | RATIONALES.md | 122 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| M | README.md | 128 | +++++++------------------------------------------------------------------------ |
2 files changed, 132 insertions(+), 118 deletions(-)
diff --git a/RATIONALES.md b/RATIONALES.md
@@ -0,0 +1,122 @@
+# Rationales
+Each of those roughly by their build order, no guarantee on this.
+
+## TCC (binary)
+Need to start somewhere and TCC allows to interpret C, allowing to avoid seeding another interpreter.
+The reason to not pick Guile+MesCC instead is because I find Guile Scheme to be less well-known than amd64 itself.
+
+## musl (binary)
+Need a libc to start somewhere, tryhards could maybe compile it from source with TCC to reduce the seed further but this hasn't been tried.
+It's `libc.a` is removed, to shave off 9.1MB from the binary seed, going from 11MB total to 1.2MB total, you're likely going to rebuild musl anyway since this is a sort of stage0.
+
+## TCC as ar(1) implementation
+Meanwhile:
+- Binutils: 300+ MiB repository of sources, generated artifacts frequently over 1MB, and test fixtures also often over 1MB. Nope.
+
+## OpenBSD ksh
+Portable version done by Dr. Brian Robert Callahan aka ibara@, of OpenBSD.
+Buildable with only a C compiler while being nicely complete (maybe even too much).
+
+Builtin commands (as of 7.6):
+- defined in c_sh.c: ., :, [, break, builtin, continue, eval, exec, exit, false, return, set, shift, times, trap, wait, read, test, true, ulimit, umask, unset, suspend
+- defined in c_ksh.c: alias, cd, command, echo, export, fc, getopts, jobs, kill, let, print, pwd, readonly, type, typeset, unalias, whence, bg, fg (and bind when emacs-mode is enabled)
+
+Meanwhile:
+- loksh: similar port but header names overrides the libc ones
+- mrsh: Too incomplete for actual use, but trivial to build with only a C Compiler
+- heirloom-sh: Also buildable with only a C Compiler but fails to allocate memory at launch
+- bash, yash: autoconf, so needs an existing shell
+- dash: autoconf and generator scripts, so needs an existing shell
+- mksh: ./Build.sh, so needs an existing shell
+- AT&T ksh: Way too big to even try, might as well try Perl
+
+## OpenBSD yacc
+Portable version done by Dr. Brian Robert Callahan aka ibara@, of OpenBSD.
+
+Uses a BSD-style configure script, trivial to diff between versions and adjust hardcoded compiler flags (no utilities to run said script yet).
+
+Meanwhile:
+- bison: autoconf, way too early
+- byacc: autoconf
+- [yacc from compilertools.net](https://web.archive.org/web/20220511161030/http://dinosaur.compilertools.net/): Domain expired years ago and turns out Gentoo was the only distro still providing it
+
+## utils-std
+My own software, which explicitly allows to bootstrap with an incomplete POSIX environment such as this one.
+
+Meanwhile:
+- GNU coreutils: Autoconf, therefore needs the utilities it's building plus some extras to already be available
+- Busybox and Toybox: Heavy dependency on GNU Make, bash, …, which can only come much later on in the bootstrapping process
+
+## sbase
+Simple `ed` and `sed` implementations which uses `regex.h` instead of some broken regex engine.
+Lack of support of `-i` option on sed(1) is a bit annoying, might patch this.
+
+Meanwhile:
+- minised: Broken regex engine which is too limited to pass `./configure` checks like the one in GNU make
+- GNU sed: `./configure` script requires an existing sed (*why*), doesn't seems like there's a workaround.
+
+## (One True) awk
+Reference implementation and AFAIK the one used in BSDs, can be built with only a Yacc implementation and a C Compiler.
+
+## pdpmake
+Public Domain POSIX make, trivial to compile without an existing make, features future POSIX additions and common extensions.
+
+Meanwhile:
+- bmake (NetBSD make port): autotools configure script, simpler than the one in GNU make but still unreviewable
+- OpenBSD make, port at <https://github.com/ibara/make> is incomplete and likely outdated
+- (OpenOffice) dmake: Horribly massive
+
+## bzip2
+Builds with C Compiler + POSIX make.
+
+Meanwhile:
+- pbzip2: Requires C++ compiler
+
+## zlib
+Simple albeit slightly broken `./configure` script (see patches).
+
+## pigz
+Simple, needs make + c compiler + zlib.
+Note: Vendored zopfli got removed, so no compression beyond -9
+
+Meanwhile:
+- GNU gzip: Autotools
+
+## Heirloom-devtools lex
+Slightly messy Makefiles but only has few dependencies.
+
+Meanwhile:
+- flex: Autotools
+
+## Heirloom-devtools m4
+Slightly messy Makefiles but only has few dependencies.
+
+Meanwhile:
+- GNU m4: Not even close
+- OpenBSD m4 aka om4: Requires a more modern lex than heirloom-devtools provides
+
+## Heirloom (toolchest) diff, sort
+Slightly messy Makefiles but only has few dependencies.
+
+## Heirloom (toolchest) tar
+Slightly messy Makefiles but only has few dependencies.
+
+Meanwhile:
+- libarchive aka bsdtar: Autotools
+- GNU tar: [No.](https://www.roguelazer.com/blog/surprising-behavior-in-gnu-tar/)
+
+## extra: genext2fs
+- e2fsprogs: complex autotools buildsystem
+- genext2fs: uses autotools but only for generating a config.h which can be vendored
+- lwext4: a lot more code than you'd need on systems like Linux which have builtin support for ext2
+
+## misc extras
+- lua: For oasis
+- muon: For pkgconf and git without autotools
+- pkgconf: For iproute2
+- GNU make: Required by the other extras
+- iproute2: Basic networking configuration
+- bearssl: small TLS library
+- tiny-curl: Still pretty big but hopefully close enough to the usual one
+- cacert (from curl.haxx.se): Maybe could be reduced to a handful of CAs (like maybe even just Let's Encrypt)
+- git: For oasis
diff --git a/README.md b/README.md
@@ -32,140 +32,32 @@ You can set `ALPINE_ARCH` to change the architecture, by default it's set to `x8
- `x86_64` (aka amd64): Works
## Rationales
-Each of those roughly by their build order.
-### TCC (binary)
-Need to start somewhere and TCC allows to interpret C, allowing to avoid seeding another interpreter.
-The reason to not pick Guile+MesCC instead is because I find Guile Scheme to be less well-known than amd64 itself.
+Moved to RATIONALES.md
-### musl (binary)
-Need a libc to start somewhere, tryhards could maybe compile it from source with TCC to reduce the seed further but this hasn't been tried.
-It's `libc.a` is removed, to shave off 9.1MB from the binary seed, going from 11MB total to 1.2MB total, you're likely going to rebuild musl anyway since this is a sort of stage0.
+## Extras
-### TCC as ar(1) implementation
-Meanwhile:
-- Binutils: 300+ MiB repository of sources, generated artifacts frequently over 1MB, and test fixtures also often over 1MB. Nope.
+The `/extras` directory is for software which is either specific
+to bootstrapping a particular system, or software which contains
+pregenerated code rather than 100% source code.
-### OpenBSD ksh
-Portable version done by Dr. Brian Robert Callahan aka ibara@, of OpenBSD.
-Buildable with only a C compiler while being nicely complete (maybe even too much).
+You can automatically build all of it with `/extras-build-all.sh`
-Builtin commands (as of 7.6):
-- defined in c_sh.c: ., :, [, break, builtin, continue, eval, exec, exit, false, return, set, shift, times, trap, wait, read, test, true, ulimit, umask, unset, suspend
-- defined in c_ksh.c: alias, cd, command, echo, export, fc, getopts, jobs, kill, let, print, pwd, readonly, type, typeset, unalias, whence, bg, fg (and bind when emacs-mode is enabled)
-
-Meanwhile:
-- loksh: similar port but header names overrides the libc ones
-- mrsh: Too incomplete for actual use, but trivial to build with only a C Compiler
-- heirloom-sh: Also buildable with only a C Compiler but fails to allocate memory at launch
-- bash, yash: autoconf, so needs an existing shell
-- dash: autoconf and generator scripts, so needs an existing shell
-- mksh: ./Build.sh, so needs an existing shell
-- AT&T ksh: Way too big to even try, might as well try Perl
-
-### OpenBSD yacc
-Portable version done by Dr. Brian Robert Callahan aka ibara@, of OpenBSD.
-
-Uses a BSD-style configure script, trivial to diff between versions and adjust hardcoded compiler flags (no utilities to run said script yet).
-
-Meanwhile:
-- bison: autoconf, way too early
-- byacc: autoconf
-- [yacc from compilertools.net](https://web.archive.org/web/20220511161030/http://dinosaur.compilertools.net/): Domain expired years ago and turns out Gentoo was the only distro still providing it
-
-### utils-std
-My own software, which explicitly allows to bootstrap with an incomplete POSIX environment such as this one.
-
-Meanwhile:
-- GNU coreutils: Autoconf, therefore needs the utilities it's building plus some extras to already be available
-- Busybox and Toybox: Heavy dependency on GNU Make, bash, …, which can only come much later on in the bootstrapping process
-
-## sbase
-Simple `ed` and `sed` implementations which uses `regex.h` instead of some broken regex engine.
-Lack of support of `-i` option on sed(1) is a bit annoying, might patch this.
-
-Meanwhile:
-- minised: Broken regex engine which is too limited to pass `./configure` checks like the one in GNU make
-- GNU sed: `./configure` script requires an existing sed (*why*), doesn't seems like there's a workaround.
-
-### (One True) awk
-Reference implementation and AFAIK the one used in BSDs, can be built with only a Yacc implementation and a C Compiler.
-
-### pdpmake
-Public Domain POSIX make, trivial to compile without an existing make, features future POSIX additions and common extensions.
-
-Meanwhile:
-- bmake (NetBSD make port): autotools configure script, simpler than the one in GNU make but still unreviewable
-- OpenBSD make, port at <https://github.com/ibara/make> is incomplete and likely outdated
-- (OpenOffice) dmake: Horribly massive
-
-### bzip2
-Builds with C Compiler + POSIX make.
-
-Meanwhile:
-- pbzip2: Requires C++ compiler
-
-### zlib
-Simple albeit slightly broken `./configure` script (see patches).
-
-### pigz
-Simple, needs make + c compiler + zlib.
-Note: Vendored zopfli got removed, so no compression beyond -9
-
-Meanwhile:
-- GNU gzip: Autotools
-
-### Heirloom-devtools lex
-Slightly messy Makefiles but only has few dependencies.
-
-Meanwhile:
-- flex: Autotools
-
-### Heirloom-devtools m4
-Slightly messy Makefiles but only has few dependencies.
-
-Meanwhile:
-- GNU m4: Not even close
-- OpenBSD m4 aka om4: Requires a more modern lex than heirloom-devtools provides
-
-### Heirloom (toolchest) diff, sort
-Slightly messy Makefiles but only has few dependencies.
-
-### Heirloom (toolchest) tar
-Slightly messy Makefiles but only has few dependencies.
-
-Meanwhile:
-- libarchive aka bsdtar: Autotools
-- GNU tar: [No.](https://www.roguelazer.com/blog/surprising-behavior-in-gnu-tar/)
-
-### extras as packed tarballs
-- genext2fs: To create an ext2 filesystem
-- lua: For oasis
-- muon: For pkgconf and git without autotools
-- pkgconf: For iproute2
-- GNU make: Required by the other extras
-- iproute2: Basic networking configuration
-- bearssl: small TLS library
-- tiny-curl: Still pretty big but hopefully close enough to the usual one
-- cacert (from curl.haxx.se): Maybe could be reduced to a handful of CAs (like maybe even just Let's Encrypt)
-- git: For oasis
-
-You can automatically build all of the above with `/extras-build-all.sh` but be warned that some use pre-generated autotools blobs which harms reviewability.
-
-You can also exclude those tarballs from the initrd with setting the `EXCLUDE_EXTRAS` environment variable to any value.
+You can exclude those tarballs from the initrd with setting
+the `EXCLUDE_EXTRAS` environment variable to any value.
## Launching in QEMU
* You need a Linux kernel, so far no known version limitations
* Combination of `panic=1` and `-no-reboot` allows to exit+relaunch
```
-$ ./make-initrd.sh && qemu-system-x86_64 -enable-kvm -m 512 -kernel /boot/vmlinuz-6.6.21-gentoo -initrd bootstrap-initrd/x86_64.cpio.gz -append 'init=/init console=ttyS0 panic=1' -nographic -no-reboot
+$ ./make-initrd.sh && qemu-system-x86_64 -enable-kvm -m 512 -kernel /boot/vmlinuz-6.6.21-gentoo -initrd bootstrap-initrd/x86_64+extras.cpio.gz -append 'init=/init console=ttyS0 panic=1' -nographic -no-reboot
```
## Dev setup via bubblewrap
```
-$ ./make-root.sh && bwrap --clearenv --unshare-all --bind bootstrap-initrd/x86_64/ / --proc /proc --dev /dev --uid 0 --gid 0 /init
+$ ./make-root.sh && bwrap --clearenv --unshare-all --bind bootstrap-initrd/x86_64+extras/ / --proc /proc --dev /dev --uid 0 --gid 0 /init
```
Useful as it allows to manipulate the environment externally, for example to edit files in an editor more comfortable than `ed(1)`.
