Use GRUB2 legacy loader for Macbook Air A1370 #3593
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Fix loading issues on this Intel-based platform as well. As described in the patch commit message, there will be likely bigger collateral effect by referring just to the CPU ID but it shouldn't have major detrimental effects. [1] #3305 (comment)
📝 WalkthroughWalkthroughThe pull request introduces a patch to the GRUB2 EFI loader that adds support for a specific Intel processor ID, enabling the use of a legacy loader for certain systems experiencing EFI boot issues. This modification specifically targets the Intel i5-2xxx processor found in Macbook Air A1370. The change includes an additional processor ID check while maintaining the existing code structure, ensuring compatibility with systems not affected by the EFI bug. Changes
Sequence Diagram(s)sequenceDiagram
participant System
participant GRUB2
participant EFI Loader
participant Legacy Loader
System->>GRUB2: Boot process initiated
GRUB2->>EFI Loader: Check processor ID
alt Processor ID matches
EFI Loader->>Legacy Loader: Switch to legacy loader
else Processor ID does not match
EFI Loader->>System: Continue with EFI boot
end
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Actionable comments posted: 0
🧹 Outside diff range and nitpick comments (1)
buildroot-external/patches/grub2/0002-loader-efi-linux-use-legacy-loader-for-broken-Intel-.patch (1)
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58-126: LGTM: Well-structured function for identifying affected platforms.The
grub_efi_has_broken_efi_stub_loaderfunction is well-implemented and consistent with the commit message. It handles both SMBIOS and SMBIOS3 tables and uses processor IDs to identify affected platforms.Consider adding a comment explaining the significance of the magic number 4 in the condition
ptr[1] >= 4. While it's mentioned in the inline comment, a brief explanation of why 4 bytes are required for a valid structure header would improve readability.
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📒 Files selected for processing (1)
- buildroot-external/patches/grub2/0002-loader-efi-linux-use-legacy-loader-for-broken-Intel-.patch (5 hunks)
🔇 Additional comments not posted (3)
buildroot-external/patches/grub2/0002-loader-efi-linux-use-legacy-loader-for-broken-Intel-.patch (3)
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1-40: LGTM: Comprehensive commit message with clear context and justification.The commit message provides a thorough explanation of the issue, the proposed solution, and potential implications. It includes references to relevant discussions and issues, which is helpful for future reference and understanding the context of the changes.
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128-140: LGTM: Correct implementation of the fallback mechanism.The changes to the
grub_cmd_linuxfunction correctly implement the fallback to the legacy loader when an affected platform is identified. This modification is consistent with the patch's objective and is implemented in a clean and straightforward manner.
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1-140: Overall assessment: Well-implemented solution for EFI loader issues on specific platforms.This patch provides a targeted solution for EFI loader issues on certain Intel and AMD platforms, including the Macbook Air A1370. The implementation is clean, well-documented, and consistent with the stated objectives. The use of processor IDs to identify affected platforms is a reasonable approach, and the fallback mechanism is implemented with minimal changes to the existing code.
The patch maintains compatibility with unaffected systems while addressing the reported issues. The comprehensive commit message and inline comments provide valuable context for future maintenance.
To ensure the patch doesn't introduce any unintended side effects, consider running the following verification steps:
These tests will help ensure that the patch doesn't conflict with other parts of the GRUB2 codebase and that similar patterns are handled consistently throughout the project.
Fix loading issues on this Intel-based platform as well. As described in the patch commit message, there will be likely bigger collateral effect by referring just to the CPU ID but it shouldn't have major detrimental effects.
[1] #3305 (comment)
Summary by CodeRabbit
New Features
Bug Fixes