The ISO boots linux-t2 on every machine. On a MacBookPro11,4 applesmc finds the
SMC and then takes a NULL pointer dereference registering the keyboard-backlight
LED, in led_trigger_set_default -> queue_work_on.
The udev worker dies mid-init holding locks and the damage spreads: reading the
half-registered LED blocks systemd-backlight, opening /dev/rfkill blocks iwd
while it holds the global misc_mtx, and every later misc device open blocks
behind that mutex. LVM opens one, so the install stops at "Cleaning up existing
holders on install disk" and never resumes — no error, no progress, nothing to
see.
Nothing in the installer needs the SMC. It reads sensors and drives the fans and
keyboard backlight, and the firmware manages the fans by itself; the installed
system still loads applesmc normally. Blacklisting it in the live environment
only, alongside the Panther Lake audio blacklist that exists for the same class
of problem.
Extracted from #102, which also carried an unrelated rework of the disk probes.
Co-Authored-By: cupatea <vladyslav@hey.com>
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Every boot entry has named vmlinuz-linux-t2 since 0638855, but the file has
contained stock Arch. Verified against the shipped ISO:
arch/boot/x86_64/vmlinuz-linux-t2:
bzImage, version 7.1.5-arch1-1 (linux@archlinux)
while the mirror carries linux-t2-7.1.4-2. T2 MacBooks have been installing
with no keyboard or trackpad in the live environment.
Kernel packages ship nothing in /boot — only usr/lib/modules/<kver>/vmlinuz.
install_kernel() in /usr/share/libalpm/scripts/mkinitcpio sources
/etc/mkinitcpio.d/<pkgbase>.preset and copies THAT package's kernel to whatever
ALL_kver names, whenever is_kernelcopy() sees an unowned absolute path. Our file
was named linux.preset, so it overrode releng's copy of the same name and
pointed the STOCK kernel at the T2 filenames. linux-t2's own generated preset
writes those same two paths, and stock won.
c23e0e7 introduced it a week after 0638855 added T2 support, so the feature
worked for exactly seven days: before the preset existed, releng's linux.preset
kept the stock kernel on its own filenames and linux-t2's generated preset
produced the real thing.
The fix is the filename. releng's linux.preset takes over the stock kernel
again, which now writes /boot/vmlinuz-linux and initramfs-linux.img instead of
squatting on the T2 names — so the ISO grows by one kernel and one archiso
initramfs. That cost is not free and is worth revisiting: the stock kernel is
in the live root only because releng's broadcom-wl hard-depends on it, and
broadcom-wl is a prebuilt module for that kernel which cannot load on the T2
one we now boot. Dropping both is ~147MB and old Broadcom Macs lose live Wi-Fi.
Boot the ISO on a T2 Mac before trusting this; the version string is only
evidence that the right kernel ships, not that it works.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
