Files
c630/docs/firmware.md
rob thijssen 18252b37f5
All checks were successful
build image / build (push) Successful in 24m42s
docs: the firmware is downloadable — WOA-Project reference drivers
The blobs turned out to be a public download rather than something to recover
from a lost backup. WOA-Project/Qualcomm-Reference-Drivers collects the
Windows-on-ARM driver cabinets by SoC, and three of them cover this machine
completely: qcdx850.cab has the zap shader and venus, qcipa850.cab has
ipa_fws.elf, and qcsubsys850.cab has the four DSP images plus WLANMDSP.MBN —
the WiFi firmware, which is not in the device tree's firmware-name list at all
and so was never on our list of things to look for.

Correct three claims elsewhere in the file that this disproves. `file` reports
these as ELF QUALCOMM DSP6 images, not as `data` — worth stating precisely,
since it is the quickest way to tell a real blob from a download that returned
an HTML error page. The sizes span 14KB to 60MB rather than "a few hundred KB
to a few MB". And the heading claiming they must come off the Windows partition
is no longer true of the easiest route.

Also narrow what c630-firmware puts in the initramfs. It globbed every .mbn in
the firmware directory, which would have pulled in the 60MB qcdsp2850.mbn and
inflated the initramfs roughly twentyfold. Only the GPU needs to be there —
msm_dpu probes at six seconds, while the initramfs is still root; the ADSP,
CDSP, SLPI, venus and modem all probe around forty seconds in and load from the
real root perfectly happily.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XWRjNJMistCy6ngXH5aJLS
2026-07-28 07:22:32 +03:00

9.9 KiB

Firmware

The C630's firmware splits into two groups, and the split is about licensing, not difficulty.

What ships in the image

Qualcomm permits redistribution of these, so Fedora packages them and the build installs them:

Package Files Enables
atheros-firmware ath10k/WCN3990/hw1.0/{firmware-5.bin,board-2.bin,wlanmdsp.mbn} WiFi and Bluetooth
qcom-firmware qcom/a630_gmu.bin, qcom/a630_sqe.fw The generic half of the Adreno 630 — necessary but not sufficient

Networking therefore works on a freshly written image. Graphics does not: see below.

What you have to supply

These are signed against per-model keys and Fedora does not ship them, so a stock install has none of them. Nothing about them is unredistributable in principle — the equivalent files for the ThinkPad X13s are in linux-firmware — it is that nobody has obtained permission for this model. See If you have no backup.

The list is not a guess: it is every firmware-name property in the mainline device tree, arch/arm64/boot/dts/qcom/sdm850-lenovo-yoga-c630.dts:

File Device tree node Lost without it
qcdxkmsuc850.mbn gpu_zap_shader Accelerated graphics
qcadsp850.mbn adsp_pas Audio — speakers, microphone
qcslpi850.mbn slpi_pas Sensor hub — lid switch, accelerometer, auto-rotate
qccdsp850.mbn cdsp_pas Compute DSP offload
qcvss850.mbn venus Hardware video decode
qcdsp1v2850.mbn mss_pil Modem, stage 1
qcdsp2850.mbn mss_pil Modem, stage 2
ipa_fws.elf ipa IPA datapath, needed by the modem

They belong under /lib/firmware/updates/qcom/sdm850/LENOVO/81JL/.

The GPU one is worth calling out, because it is easy to assume otherwise: Fedora does ship an sdm845/a630_zap.mbn, but that is the generic Snapdragon 845 zap shader and not what this device asks for. The C630's device tree names qcom/sdm850/LENOVO/81JL/qcdxkmsuc850.mbn specifically, so until you supply it you get an unaccelerated display.

Each file is independent, so a partial recovery is still worth having — qcdxkmsuc850.mbn on its own buys you working graphics.

Confirmed on the hardware

This is not inferred from the device tree. On a machine with the generic Adreno firmware present and the model-signed blob absent, the GPU gets two files in and then stops:

[drm:adreno_request_fw]   loaded qcom/a630_sqe.fw from new location
[drm:adreno_request_fw]   loaded qcom/a630_gmu.bin from new location
[drm:zap_shader_load_mdt] *ERROR* Unable to load qcom/sdm850/LENOVO/81JL/qcdxkmsuc850.mbn
[drm:adreno_load_gpu]     *ERROR* gpu hw init failed: -2

So the generic pieces are necessary and not sufficient, and the zap shader is a hard requirement rather than an optimisation. Two details follow from that trace:

The driver never falls back to sdm845/a630_zap.mbn, even though the file is installed — the device tree's firmware-name pins the model-specific path. Nor would falling back help: the zap shader is signed against the device's own secure-boot chain, and the Snapdragon 845 development board's copy will not validate here.

The display keeps working throughout. msm_dpu binds the panel and the console lands on msmdrmfb regardless, so a failed GPU costs you acceleration, not a picture. A desktop still runs on llvmpipe — though /dev/dri/renderD128 is present even when hw init has failed, so mesa may try freedreno, fail, and take the display manager down with it. LIBGL_ALWAYS_SOFTWARE=1 in /etc/environment avoids that.

These have to be in the initramfs

msm_dpu probes about six seconds in, while the initramfs is still the root filesystem, and does not retry. Firmware that only exists on the real root is therefore invisible to it:

msm_dpu ae01000.display-controller: Direct firmware load for qcom/a630_sqe.fw failed with error -2

overlay/etc/dracut.conf.d/10-c630.conf puts the Adreno files in the initramfs for this reason, and c630-firmware adds qcdxkmsuc850.mbn once it exists.

Only the GPU needs this. The ADSP, CDSP, SLPI, venus and modem all probe around forty seconds in, well after the real root is mounted, and load from it perfectly happily. That distinction is worth keeping: qcdsp2850.mbn alone is 60 MB, so sweeping the whole firmware directory into the initramfs would inflate it roughly twentyfold for no benefit.

Finding them on a backup

If Windows is long gone from the machine but you kept a copy of the files, one search catches all eight, since seven share a suffix:

find /mnt/backup -type f \
    \( -iname 'qc*850.mbn' -o -iname 'ipa_fws.elf' -o -iname 'bdwlan*.bin' \) \
    -printf '%10s  %p\n'

They originally lived in C:\Windows\System32\DriverStore\FileRepository\, in directories named qcdx850.inf_arm64_* and qcadsp*.inf_arm64_*. If the loose files turn up nothing, look for those directories wholesale:

find /mnt/backup -type d -iname 'qc*.inf_arm64_*'

Sizes range from 14 KB (qcdxkmsuc850.mbn) to 60 MB (qcdsp2850.mbn). Despite the .mbn extension they are ELF images, and file should say so:

qcdxkmsuc850.mbn: ELF 32-bit LSB executable, QUALCOMM DSP6, version 1 (SYSV)

Anything reporting as text or HTML is a download that went wrong.

Lenovo does not appear to publish a driver package for the 81JL containing these. If the backups turn up nothing, see If you have no backup — the files are not tied to your individual machine, so yours is not the only possible source.

If you have no backup

Losing the Windows partition is not the end of it, because these blobs are signed per model, not per machine. A copy from any other Yoga C630 works on yours.

The evidence is in linux-firmware itself, which already ships the exact analogous set for the ThinkPad X13s — one copy serving every unit of that model:

qcom/sc8280xp/LENOVO/21BX/qcdxkmsuc8280.mbn     zap shader
qcom/sc8280xp/LENOVO/21BX/qcadsp8280.mbn        audio
qcom/sc8280xp/LENOVO/21BX/qccdsp8280.mbn        compute DSP
qcom/sc8280xp/LENOVO/21BX/qcslpi8280.mbn        sensors
qcom/sc8280xp/LENOVO/21BX/qcvss8280.mbn         video

A one-to-one match with the C630's list, differing only in the model. So these files are redistributable once Lenovo and Qualcomm permit it — it is a licensing question, not a technical one.

qcom/sdm850/LENOVO/81JL/ has simply never been contributed. Fedora ships no sdm850 model firmware at all, so it will not turn up in a linux-firmware update. Three routes, easiest first:

The WOA-Project reference drivers. https://github.com/WOA-Project/Qualcomm-Reference-Drivers collects the Windows-on-ARM driver packages by SoC. The C630's are three cabinet files, and between them they hold every file this machine asks for:

Cabinet Contains
qcdx850.cab qcdxkmsuc850.mbn (zap shader), qcvss850.mbn (venus)
qcipa850.cab ipa_fws.elf
qcsubsys850.cab qcadsp850.mbn, qccdsp850.mbn, qcslpi850.mbn, qcdsp1v2850.mbn, qcdsp2850.mbn, and WLANMDSP.MBN

That last one is a bonus — the WiFi firmware, which is not in the device tree's firmware-name list but is what the onboard ath10k needs.

cabextract or 7z x will open them:

for f in qcdx850.cab qcipa850.cab qcsubsys850.cab; do 7z x -o./extracted "$f"; done
find ./extracted -iname 'qc*850.mbn' -o -iname 'ipa_fws.elf' -o -iname 'WLANMDSP.MBN'

Ignore the _nm and _CLS variants; the device tree asks for the plain names. Verify what you get with file — they should report as ELF 32-bit LSB executable, QUALCOMM DSP6, not as text or HTML.

Lenovo's Digital Download Recovery Service. Lenovo builds a Windows recovery image against a machine's serial number and lets the owner download it. That image contains Windows/System32/DriverStore/FileRepository, and therefore all eight files. Slower than the cabinets, but it is unambiguously your own machine's firmware.

Another C630 owner. The aarch64-laptops project is where these have circulated before, and any 81JL's copy is as good as your own.

Whichever route, drop the result into firmware/local/ and rebuild — see Baking firmware into the image.

Extracting them

The image ships Fedora's qcom-firmware-extract. Run it once:

sudo c630-firmware
sudo reboot

That wraps qcom-firmware-extract and regenerates the initramfs afterwards, which matters — the ADSP firmware has to be available before the root filesystem is mounted, and overlay/etc/dracut.conf.d/10-c630.conf only takes effect on a rebuild.

If it cannot find Windows, mount it yourself and point the tool at it:

lsblk -o NAME,SIZE,FSTYPE,LABEL       # find the NTFS partition
sudo mkdir -p /mnt/windows
sudo mount /dev/sda4 /mnt/windows
sudo qcom-firmware-extract --windows-dir /mnt/windows

qcom-firmware-extract was written for the Snapdragon 8cx and X Elite laptops. If it does not recognise the SDM850, copy the files by hand — they are in Windows/System32/DriverStore/FileRepository/ under a qcdx*.inf_arm64_* directory:

sudo find /mnt/windows/Windows/System32/DriverStore/FileRepository \
    -iname 'qc*850.mbn' -o -iname 'ipa_fws.elf' -o -iname 'qcdxkmsuc850.mbn'

sudo mkdir -p /lib/firmware/updates/qcom/sdm850/LENOVO/81JL
sudo cp <each file> /lib/firmware/updates/qcom/sdm850/LENOVO/81JL/
sudo dracut --force --regenerate-all

Check it took:

dmesg | grep -iE 'remoteproc|adsp|cdsp'

Baking firmware into the image

If you would rather not repeat the extraction on every reinstall, drop the files into firmware/local/ in this repo, mirroring the /usr/lib/firmware/updates/ layout:

firmware/local/qcom/sdm850/LENOVO/81JL/qcadsp850.mbn
firmware/local/qcom/sdm850/LENOVO/81JL/qccdsp850.mbn
...

build/stage2.sh picks them up automatically. They are gitignored, and should stay that way — this repository is public and the blobs are not yours to publish.