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

[Ard Biesheuvel]

On Tue, 11 Mar 2025 at 18:14, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>
> >Ard Biesheuvel <ardb+git@xxxxxxxxxx> writes:
> >
...
> >> 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.
> >>
...
>
> Please leave the bytes in question as explicit zeroes if possible.

Keeping the

. = ALIGN(. + 4, 0x200);

in arch/x86/boot/compressed/vmlinux.lds.S should be sufficient to
guarantee that the last 4 bytes of the file are zero, so it is quite
trivial to implement. However, I'm not quite sure what purpose that
would serve: could you elaborate?