Re: [PATCH v1 0/3] x86/boot: Supply boot_param in rdi instead of rsi from startup_64()

[Brian Gerst]

On Mon, Jun 23, 2025 at 2:40 PM Khalid Ali <khaliidcaliy@xxxxxxxxx> wrote:
>
> > This is also invoked by some external bootloaders that boot the ELF
> > image directly, even though this is strongly discouraged.
> >
> > Therefore this patchset is NAKed with extreme prejudice.
>
> Thanks both of you peter and brian,
>
> however, the boot protocol document saying "%rsi must hold the base address of the struct boot_params",
> it doesn't mention why. Maybe the document needs update to justify the reasons. I wouldn't have known it
> if you didn't tell me, so this shouldn't confuse anyone else.

The use of RSI was inherited from the 32-bit kernel, but the real
reason is lost to history.  It's just always been that way and there
is no compelling reason to change it.


Brian Gerst