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Mathieu Benoit 6f44fdb572 [FIX] lvm2: only device-mapper, and the closure closes
The fourth closure round asked for libaio and thin-provisioning-tools, both
wanted by lvm2 alone. thin-provisioning-tools is Rust now, so a language
runtime was arriving through a fourth-order dependency.

Nothing in the repository wants `lvm2`. Checked across every .PKGINFO:
cryptsetup wants device-mapper, and device-mapper is the other package this
same source produces. Dropping the sub-package removed both entries and the
Rust question with them.

The measurement is the argument, and it went the other way an hour earlier.
tcl, unixodbc and libmicrohttpd each cost zero new packages, so building them
beat dropping sub-packages. This one costs a language runtime, so dropping
wins. The rule is not to prefer either -- it is to measure each time.

device-mapper had also picked up the host's libselinux, silently. Seventh
package to do it, second found by reading binaries rather than by a build.

35 packages, then 19, then 2, then 0.

--- FR ---

Le quatrième tour de fermeture réclamait libaio et thin-provisioning-tools,
tous deux voulus par lvm2 seul. thin-provisioning-tools est en Rust
désormais : un environnement de langage arrivait par une dépendance de
quatrième ordre.

Rien dans le dépôt ne veut `lvm2`. Vérifié sur chaque .PKGINFO : cryptsetup
veut device-mapper, et device-mapper est l'autre paquet que cette même source
produit. Écarter le sous-paquet a retiré les deux entrées et la question Rust
avec elles.

La mesure est l'argument, et elle avait tranché dans l'autre sens une heure
plus tôt. tcl, unixodbc et libmicrohttpd coûtaient zéro paquet nouveau : les
bâtir valait mieux qu'écarter des sous-paquets. Celui-ci coûte un
environnement de langage : écarter gagne. La règle n'est de préférer ni l'un
ni l'autre — c'est de mesurer chaque fois.

device-mapper avait aussi ramassé le libselinux de l'hôte, en silence.
Septième paquet à le faire, deuxième trouvé en lisant des binaires plutôt que
par une compilation.

35 paquets, puis 19, puis 2, puis 0.

Assisted-by: Claude Opus 5
2026-08-19 06:40:50 -04:00
.github/workflows making the house a home 2026-01-27 23:26:31 +01:00
arch-kernel making the house a home 2026-01-27 23:26:31 +01:00
boot making the house a home 2026-01-27 23:26:31 +01:00
patches [FIX] lvm2: only device-mapper, and the closure closes 2026-08-19 06:40:50 -04:00
scripts [FIX] lvm2: only device-mapper, and the closure closes 2026-08-19 06:40:50 -04:00
.env.example full boot with systemd 2025-06-05 12:32:34 +02:00
.gitignore making the house a home 2026-01-27 23:26:31 +01:00
CODEOWNERS making the house a home 2026-01-27 23:26:31 +01:00
Containerfile making the house a home 2026-01-27 23:26:31 +01:00
LICENSE use arch kernel patches 2025-06-02 21:53:33 +02:00
Makefile making the house a home 2026-01-27 23:26:31 +01:00
README.md making the house a home 2026-01-27 23:26:31 +01:00
TODO.md [UPD] TODO: the category the other three did not cover 2026-08-17 02:37:46 -04:00

Arch Linux s390x

A port of Arch Linux to IBM s390x mainframe architecture with systemd support.

Boots a full Arch Linux system on IBM mainframes (or QEMU s390x emulation) using a hybrid build: cross-compilation for the kernel, native s390x compilation on z/VM for userspace.

Quick Start

make container        # build dev container (first time)
cp .env.example .env  # configure z/VM access
make all              # build kernel + initramfs + systemd
make test-systemd     # boot it

What Works

  • Arch Linux kernel 6.18.6-arch1 with Arch patches, cross-compiled
  • Initramfs via modified mkinitcpio
  • Static busybox built natively on z/VM, 2.3MB
  • Root filesystem with ext4, switch_root to real rootfs
  • Systemd as PID 1

Pacman, bash, and GNU coreutils are not yet ported.

Build System

The build uses two tiers:

Cross-compilation (x86_64 host): Kernel is built in a Fedora 43 container with s390x-linux-gnu-gcc. Initramfs is generated with a patched mkinitcpio that handles cross-architecture binary injection.

Native compilation (s390x z/VM): Busybox and systemd must be built on real s390x hardware. The z/VM system runs RHEL 9.6 with GCC 11.5.0. Scripts handle SSH deployment and retrieval automatically via .env configuration.