Re: [PATCH 17/17] x86/boot: Drop CRC-32 checksum and the build tool that generates it

From: H. Peter Anvin
Date: Sun Aug 20 2023 - 20:37:58 EST


On 8/20/23 05:57, Ard Biesheuvel wrote:

I understand. I deliberately put this change at the very end because I
was anticipating some debate on this.

Do you have any recollection of why this CRC32 was introduced in the
first place? The commit logs are empty and the lore thread doesn't
contain any justification either.
>

The justification is that firmware is notoriously unreliable and gives the boot loader an independent way to verify the load and have a fallback, rather than jumping to the kernel and having the decompressor fail.

At this time it is impossible to know what might rely on it. The EFI signing issue aside, there are a ton of Linux bootloaders for non-EFI systems using the BIOS or raw kernel entry points - and there is no telling what those environments might do.

-hpa