Public bug reported:
Background: Huawei Matebook E Go (Code Name: gaokun3) referred is a
Qualcomm Snapdragon SC8280XP device whose DTB is in mainline Linux.
Huawei Qingyun W510 is a workstation based on Kunpeng 920 (Taishan
V110*24) which is a standard arm processor using UEFI and ACPI with NO
NEED for a loader-supplied DTB. W510's firmware DOES NOT provide DTB
either.
W510's SMBIOS reads "Manufacturer=HUAWEI、ProductSku=C233" which is same
to gaokun3's.
Stubble's devicetree.c:firmware_devicetree_exists() checks if there's
DTB in config table. W510 has none so it turns to HWID path.
chid_match() reads "type 7 = Manufacturer + ProductSku" so W510's CHID
computed is 7ea8b73b-2cbb-562b-aecc-7f0f64c42630 and exactly matches
gaokun3 in Ubuntu's official vmlinuz's ".hwids". Then in
pe.c:pe_use_this_dtb(), devicetree_match() returns EFI_UNSUPPORTED (no
firmware DTB), so it falls through to the HWID branch:
device_get_compatible() yields "huawei,gaokun3", and
devicetree_match_by_compatible() selects the 153 KB .dtbauto section
whose root compatible is "huawei,gaokun3" (file offset 0x546e00 inside
vmlinuz). devicetree_install_from_memory() then installs it via
InstallConfigurationTable(EFI_DTB_TABLE, ...). The inner zboot stub
prints "EFI stub: Using DTB from configuration table" and the kernel
boots in DT mode with gaokun3's device tree on a Kunpeng 920 — the
machine hangs silently right after "EFI stub: Exiting boot services...".
Release Version: Ubuntu 26.04.1 LTS
Package Version: stubble 9-1 (bundled in linux-image-7.0.0-31-generic
7.0.0-31.31)
Expected: stubble should not install any DTB on this machine; the kernel should
boot via ACPI.
Actual: W510 hangs silently at boot with any official Ubuntu 26.04 arm64 kernel
(7.0.0-15.15 and 7.0.0-31.31 tested).
** Affects: stubble (Ubuntu)
Importance: Undecided
Status: New
** Attachment added: "bug-attachments.tar.xz"
https://bugs.launchpad.net/bugs/2166697/+attachment/5998331/+files/bug-attachments.tar.xz
** Description changed:
Background: Huawei Matebook E Go (Code Name: gaokun3) referred is a
Qualcomm Snapdragon SC8280XP device whose DTB is in mainline Linux.
Huawei Qingyun W510 is a workstation based on Kunpeng 920 (Taishan
V110*24) which is a standard arm processor using UEFI and ACPI with NO
NEED for a loader-supplied DTB. W510's firmware DOES NOT provide DTB
either.
W510's SMBIOS reads "Manufacturer=HUAWEI、ProductSku=C233" which is same
to gaokun3's.
Stubble's devicetree.c:firmware_devicetree_exists() checks if there's
DTB in config table. W510 has none so it turns to HWID path.
chid_match() reads "type 7 = Manufacturer + ProductSku" so W510's CHID
computed is 7ea8b73b-2cbb-562b-aecc-7f0f64c42630 and exactly matches
gaokun3 in Ubuntu's official vmlinuz's ".hwids". Then in
pe.c:pe_use_this_dtb(), devicetree_match() returns EFI_UNSUPPORTED (no
firmware DTB), so it falls through to the HWID branch:
device_get_compatible() yields "huawei,gaokun3", and
devicetree_match_by_compatible() selects the 153 KB .dtbauto section
whose root compatible is "huawei,gaokun3" (file offset 0x546e00 inside
vmlinuz). devicetree_install_from_memory() then installs it via
InstallConfigurationTable(EFI_DTB_TABLE, ...). The inner zboot stub
prints "EFI stub: Using DTB from configuration table" and the kernel
boots in DT mode with gaokun3's device tree on a Kunpeng 920 — the
- machine hangs silently right after "EFI stub: Exiting boot services...",
- before any console output.
+ machine hangs silently right after "EFI stub: Exiting boot services...".
Release Version: Ubuntu 26.04.1 LTS
Package Version: stubble 9-1 (bundled in linux-image-7.0.0-31-generic
7.0.0-31.31)
Expected: stubble should not install any DTB on this machine; the kernel
should boot via ACPI.
Actual: W510 hangs silently at boot with any official Ubuntu 26.04 arm64
kernel (7.0.0-15.15 and 7.0.0-31.31 tested).
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https://bugs.launchpad.net/bugs/2166697
Title:
stubble HWID false positive loads wrong DTB, boot hang on HUAWEI W510
(Kunpeng 920)
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