bcm2711: don't wipe the firmware kernel when removing one of several kernels - #10783
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…kernels On RPi /boot/firmware (the vfat partition read by config.txt: kernel=vmlinuz) is populated by two /etc/kernel hooks. The postrm hook zzz-remove-old-files did an unconditional: rm /boot/firmware/vmlinuz rm /boot/firmware/*.dtb rm -r /boot/firmware/overlays Those files are SHARED: they are not tied to the kernel being removed. So installing a second kernel and then removing the first wipes the kernel the surviving one needs, leaving the firmware partition with only initrd.img and no kernel/dtb -> the Pi will not boot. Reproduced by an autotests kernel-branch switch (install edge, then purge current): the current purge deleted the edge kernel/dtbs from /boot/firmware and bricked the board, even though the edge kernel was intact on the ext4 /boot. Fix the removal hook to RE-SYNC the firmware from the newest kernel image still installed under /boot (ignoring the one being removed), and only clear the firmware when no kernel remains. Also fix the copy hook (zzz-copy-new-files) to install the versioned image of the kernel being installed (/boot/vmlinuz-$abi) rather than /boot/Image: that hook runs via run-parts before the kernel postinst relinks /boot/Image, so /boot/Image can still point at an older kernel when more than one is installed. Now install/remove order no longer matters: switching branches and pruning the old one always leaves /boot/firmware reflecting an installed, bootable kernel. Verified by extracting both generated hooks and exercising: (A) install edge while /boot/Image points at current -> firmware = edge; (B) purge edge while current remains -> firmware re-synced to current; (C) purge the last kernel -> firmware cleared. Signed-off-by: Igor Pecovnik <igor@armbian.com>
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Included review availability: Your plan provides up to 8 included reviews per hour; 6 remain after this review. 📝 WalkthroughWalkthroughThe BCM2711 hooks now synchronize firmware from versioned kernel images. Installation fails when the expected image is absent. Removal prefers the active kernel and uses atomic overlay replacement. ChangesBCM2711 kernel synchronization
Priority: ⬇️ Low Estimated code review effort: 2 (Simple) | ~10 minutes Change: Bug fix 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
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Inline comments:
In `@config/sources/families/bcm2711.conf`:
- Around line 128-129: Remove the /boot/Image fallback from the kernel staging
branch; when /boot/vmlinuz-${abi} is absent, the existing error path must fail
the hook instead of copying an older kernel. Update the conditional around the
vmlinuz staging logic while preserving the matching-kernel copy behavior.
- Around line 153-179: In the newest-kernel branch, update the post-removal hook
to delete existing `${target}/*.dtb` files before copying DTBs from
`/usr/lib/linux-image-${newest}/broadcom`. Keep the existing copy behavior and
cleanup for the no-kernel branch unchanged.
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config/sources/families/bcm2711.conf
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…ay swap Review of the initial fix raised valid points; harden both hooks: * postrm: sync the firmware to the ACTIVE kernel (whatever /boot/Image points at) instead of "newest remaining", so removing an unrelated old kernel (apt autoremove) can no longer silently switch which kernel the Pi boots. Only when the active kernel itself was the one removed (/boot/Image now dangling) do we fall back to the newest kernel still installed; clear the firmware when none remain. * Both hooks: refresh overlays atomically (stage overlays.tmp with `cp -rT`, then swap) so a failed copy under set -e aborts before the good overlays are removed, and there is no overlays/overlays nesting on re-run. Drop the `2>/dev/null || true` from the postrm copies so a real failure surfaces, like the postinst path already does. * postinst: require /boot/vmlinuz-$abi (error out if missing) instead of falling back to /boot/Image, which run-parts may see pointing at an older kernel -- the exact staleness this fix set out to avoid. Verified by extracting both generated hooks (bash -n clean) and exercising: install-edge (Image->current) -> firmware edge; purge current (edge active) -> edge; autoremove an old current while running current with edge also installed -> firmware STAYS on the running current; purge the active kernel -> falls back to newest remaining; purge last kernel -> firmware cleared; repeated install -> no overlays nesting. Signed-off-by: Igor Pecovnik <igor@armbian.com>
Validated end-to-end in CI on real hardware ✅The autotests board pipeline exercised the exact Run autotests #35619198145 — overall: pass. Per-branch results (each branch actually booted, confirmed by
Before this fix, the This complements the manual hardware checks on the same class of board: install current → purge edge kept firmware=current; switch to edge → purge current kept firmware=edge (byte-identical); reboot booted edge. |
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Problem
On Raspberry Pi,
/boot/firmware(the vfat partition the GPU firmware reads;config.txthaskernel=vmlinuz) is populated by two/etc/kernelhooks generated inbcm2711.conf. The postrm hookzzz-remove-old-filesdid an unconditional:rm /boot/firmware/vmlinuz rm /boot/firmware/*.dtb rm -r /boot/firmware/overlaysThose files are shared — not tied to the kernel being removed. So installing a second kernel and then removing the first wipes the kernel the surviving one needs, leaving
/boot/firmwarewith onlyinitrd.imgand no kernel/dtb → the Pi won't boot.Reproduced by an autotests kernel-branch switch (
install edge, thenpurge current): current's purge deleted the edge kernel/dtbs/overlays from/boot/firmwareand bricked the board — even though the edge kernel was fully intact on the ext4/boot. (Confirmed on the pulled SD card:/boot/firmwarehadinitrd.imgbut novmlinuz/*.dtb/overlays.)Fix
zzz-remove-old-files): instead of deleting, re-sync/boot/firmwarefrom the newest kernel image still installed under/boot(ignoring the one being removed); only clear the firmware when no kernel remains.zzz-copy-new-files): copy the versioned image of the kernel being installed (/boot/vmlinuz-$abi) rather than/boot/Image. This hook runs viarun-partsbefore the kernel postinst relinks/boot/Image, so/boot/Imagecan still point at an older kernel when more than one is installed.Install/remove order no longer matters: switching branches and pruning the old one always leaves
/boot/firmwarereflecting an installed, bootable kernel.Testing
Extracted both generated hooks and exercised them against a fake tree (
bash -nclean on both):/boot/Image→ current ⇒ firmware = edgeRelated
Same "don't destroy the boot state of the surviving kernel" theme as build#10766 / build#10775 / configng#1025, but specific to the RPi vfat firmware partition. Unrelated to DKMS.
Signed-off-by: Igor Pecovnik igor@armbian.com
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