diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2025-03-07 17:48:02 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-03-07 23:59:10 +0100 |
| commit | 9c54baab4401db249d6938806b812231e0259380 (patch) | |
| tree | ac39a67ba22de40dfed1544438dc39e01ba816c8 /arch/x86/boot/compressed | |
| parent | e451630226bd09dc730eedb4e32cab1cc7155ae8 (diff) | |
x86/boot: Drop CRC-32 checksum and the build tool that generates it
Apart from some sanity checks on the size of setup.bin, the only
remaining task carried out by the arch/x86/boot/tools/build.c build tool
is generating the CRC-32 checksum of the bzImage. This feature was added
in commit
7d6e737c8d2698b6 ("x86: add a crc32 checksum to the kernel image.")
without any motivation (or any commit log text, for that matter). This
checksum is not verified by any known bootloader, and given that
a) the checksum of the entire bzImage is reported by most tools (zlib,
rhash) as 0xffffffff and not 0x0 as documented,
b) the checksum is corrupted when the image is signed for secure boot,
which means that no distro ships x86 images with valid CRCs,
it seems quite unlikely that this checksum is being used, so let's just
drop it, along with the tool that generates it.
Instead, use simple file concatenation and truncation to combine the two
pieces into bzImage, and replace the checks on the size of the setup
block with a couple of ASSERT()s in the linker script.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250307164801.885261-2-ardb+git@google.com
Diffstat (limited to 'arch/x86/boot/compressed')
| -rw-r--r-- | arch/x86/boot/compressed/vmlinux.lds.S | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index 083ec6d7722a..48d0b5184557 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -48,8 +48,7 @@ SECTIONS *(.data) *(.data.*) - /* Add 4 bytes of extra space for a CRC-32 checksum */ - . = ALIGN(. + 4, 0x200); + . = ALIGN(0x200); _edata = . ; } . = ALIGN(L1_CACHE_BYTES); |