This series fixes ACPI BGRT (Boot Graphics Resource Table) corruption, that occured when Xen reuses the memory containing the boot logo image before dom0 is able to parse ACPI tables.
The BGRT table contains a pointer to a BMP image stored in BootServicesData memory. When Xen reclaims this memory early in boot, the pointer becomes invalid, causing Linux dom0 to report: Xen: `(XEN) ACPI: BGRT: invalidating v1 image at 0x47cc2018` Linux (dom0): `ACPI BIOS Warning (bug): Incorrect checksum in table [BGRT] - 0xF9, should be 0xB4 (20250807/utcksum-58)` This series: 1. Adds BGRT image preservation during EFI boot (similar to ESRT) 2. Removes the now-unnecessary invalidation code 3. Provides an opt-out mechanism (efi=no-bgrt) for servers The preservation is enabled by default to fix the corruption for all users, with minimal overhead (~1MB). Also, servers that don't need boot graphics can disable it using the "efi=no-bgrt" option. Testing: - Verified on Intel UEFI system with Fedora 43 dom0 - Before: ACPI checksum errors in dom0 - After: Clean boot, no ACPI warnings - Memory overhead: ~972 KB (preserved image size) Signed-off-by: Soumyajyotii Ssarkar <[email protected]> Soumyajyotii Ssarkar (3): x86/efi: Add BGRT image preservation during boot x86/acpi: Remove BGRT invalidation code x86/efi: Add opt-out mechanism for BGRT preservation xen/arch/x86/acpi/boot.c | 23 ----- xen/arch/x86/efi/efi-boot.h | 2 + xen/common/efi/boot.c | 199 ++++++++++++++++++++++++++++++++++++ 3 files changed, 201 insertions(+), 23 deletions(-) -- 2.53.0
