From 7e4c4cabf2581e64b28e6970f9209adbb243a009 Mon Sep 17 00:00:00 2001 From: "prompt.ac/@jeffrey" Date: Thu, 24 Sep 2026 18:05:20 -0700 Subject: [PATCH] ac-os chromebook kpart: force the SOF audio driver on the depthcharge path The kernel's DSP auto-select takes SOF on Gemini/Jasper Lake only when the NHLT table lists DMICs. The HP Chromebook "Meep" has none, so its DSP went to legacy snd_hda_intel, produced a codec-less "HDA Intel PCH" card and no sound. snd_intel_dspcfg.dsp_driver is read-only after boot, so it rides the kpart command line: every Chromebook booting this partition has a SOF-era DSP, and UEFI boots are untouched. --- fedac/native/docker-build.sh | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fedac/native/docker-build.sh b/fedac/native/docker-build.sh index f8d7f52e2f..1151f9c6aa 100644 --- a/fedac/native/docker-build.sh +++ b/fedac/native/docker-build.sh @@ -1146,7 +1146,14 @@ else exit 1 fi KPART="$BUILD/vmlinuz.kpart" - printf 'ac.boot=chromeos' > "$BUILD/kpart-cmdline.txt" + # snd_intel_dspcfg.dsp_driver=3 forces the SOF path for the audio DSP. + # The kernel's auto-select takes SOF on Gemini/Jasper Lake only when the + # NHLT table lists DMICs; the HP "Meep" (no DMICs in NHLT) fell back to + # legacy HDA, got a codec-less "HDA Intel PCH" card and no sound + # (2026-09-24). Every Chromebook that boots this kpart has a SOF-era DSP, + # and the parameter is read-only after boot, so it rides the kpart + # command line only — UEFI boots (ThinkPads, Macs) are untouched. + printf 'ac.boot=chromeos snd_intel_dspcfg.dsp_driver=3' > "$BUILD/kpart-cmdline.txt" # x86 depthcharge ignores the bootloader blob but vbutil_kernel insists on one. dd if=/dev/zero of="$BUILD/kpart-bootstub.bin" bs=512 count=1 status=none "$VBUTIL" --pack "$KPART" \ -- 2.51.2