Booting via BMC virtual CD reads the ~2.8 GB filesystem squashfs
sequentially during the live-boot toram copy; a mid-read drop of the
redirected medium loses the whole copy and fails the boot (v14). Split
the rootfs into self-contained semantic layers so a retry re-reads at
most one ~500-700 MiB layer, not everything. This is a resilience /
reduced-re-read mechanism, not a fix for the virtual-media instability.
NVIDIA variants now ship 7 layers (00-base, 05-firmware, 08-desktop,
10-nvidia-driver, 20-nvidia-platform, 30-nvidia-cuda-libs,
40-nvidia-dcgm-cuda) plus an explicit live/filesystem.module that fixes
their OverlayFS order; amd/nogpu keep a single squashfs.
- lib/squashfs-layers.sh: deterministic classifier (dpkg file ownership
plus explicit rules for build.sh-injected files, never a path
substring), per-layer mksquashfs, 800 MiB hard ceiling, unsquashfs -s
plus strict extraction of every layer, merged-rootfs bootability check.
- build.sh: split the monolith after the full lb build, verify and merge,
write the module file, delete the monolith only then; abort before ISO
assembly on any failure. Runs the builder test suites up front.
- fast-path: force a full build for a multi-layer medium;
fast_path_repack_squashfs hard-refuses (it would drop layers).
- iso-validation.sh: validate_iso_squashfs_layers (module vs layer set
match, size ceiling, no lone giant squashfs) and
validate_iso_media_integrity (xorriso -check_media).
- bee-install: honour filesystem.module order, abort on any layer failure.
- 9013-toram-retry: record the real rsync exit code (it printed a false
rc=0) and correct the "resumes the tail" comment (rsync without
--partial keeps only fully-copied layers). No unsafe partial resume.
- tests: test-squashfs-layers.sh plus a multi-layer guard in
test-build-libs.sh; both run at the top of every build.
- docs: bible-local architecture and decision, iso/README, iso-build-rules.
Verified by a full nvidia build: 7 layers 622/199/256/466/37/567/562 MiB,
every validator passes, xorriso -check_media good, merged rootfs bootable.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The NVIDIA GSP firmware was staged into the overlay at a bare
lib/firmware/nvidia/<ver>/. On a merged-usr Debian root /lib is a symlink
to usr/lib, so the fast-path repack's `rsync -a` (overlay stage -> the
unsquashfs'd tree) replaced that symlink with a plain directory holding
only the firmware. Everything else reachable only through /lib
(/lib/systemd/systemd, /lib/x86_64-linux-gnu/ld-linux + libc, ...) was
orphaned. The squashfs still packed and mounted, but boot panicked:
run-init: can't execute '/sbin/init': No such file or directory
run-init: can't execute '/bin/sh': No such file or directory
Kernel panic - not syncing: Attempted to kill init
Full `lb build` was unaffected (live-build copies includes.chroot with
cp -a, which follows the /lib symlink), so only fast-path ISOs were bad.
Three fixes:
- build.sh: stage GSP firmware under usr/lib/firmware/nvidia/<ver>/, the
canonical merged-usr path. Changing the overlay path also makes
overlay_paths_were_removed() force one full build on the next run.
- fast-path.sh: add `rsync --keep-dirlinks` so a real directory in the
overlay stage can never again replace a symlink-to-directory in the
root. Verified: firmware lands in usr/lib/firmware, /lib stays a symlink.
- iso-validation.sh: new validate_iso_rootfs_layout, run for every variant
on both build paths. Fails the build if the squashfs has a plain-dir
/bin|/sbin|/lib|/lib64, or if /usr/sbin/init is present without a
resolvable /usr/lib/systemd/systemd and /lib symlink. Verified it flags
the broken v14.02-1-g642e686 ISO and passes a correct layout.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H2LLuid8PFhBqBPcxXxkQU
needs_full_build() decided the fast path was safe by hashing only config
inputs (VERSIONS, package lists, hooks, archives, auto/config, Dockerfile).
It never hashed the build logic itself, so a change to build.sh or
lib/fast-path.sh counted as a "light" file and the next build silently
reused a squashfs produced by the old code. The merged-usr /lib fix in the
previous commit only forced a full rebuild by accident (the overlay
manifest saw firmware move from lib/ to usr/lib/).
hash_heavy_config now covers every *.sh under iso/builder (build.sh, the
build-*.sh helpers, lib/*.sh) plus auto/. A change to build logic is now
as heavy as a package-list change. config/bootloaders stays excluded (the
fast path regenerates the outer ISO layer from it every time). Hash is
deterministic (LC_ALL=C sort).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H2LLuid8PFhBqBPcxXxkQU
