Re: [PATCH 3/6] x86/efi: discard .text.header for PE binary

[Frediano Ziglio <freddy77@xxxxxxxxx>]

On Tue, 2 Jun 2026 at 13:15, Jan Beulich <jbeulich@xxxxxxxx> wrote:
>
> On 29.05.2026 17:35, Frediano Ziglio wrote:
> > From: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> >
> > The multiboot headers are not consumed in the PE binary, hence discard them
> > in the linker script when doing a PE build.
>
> Yet weren't there plans to allow making use of those headers even in xen.efi?
>

That method was replaced by different ways of loading. Using multiboot
for PE would require some extensions to multiboot as the protocol is
not designed to support PE format. There are already ways to use EFI
and configuration files that can be used. We (as Citrix) are going
(not me personally) to post changes to extend xen_hypervisor and
xen_module (used currently only by ARM) to x64. These changes are much
smaller, maintainable and coherent.

> > That removes some relocations that otherwise appear due to the usage of the
> > start and __efi64_mb2_start symbols in the multiboot2 header.
> >
> > No functional change intended.
> >
> > Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> > ---
> >  xen/arch/x86/xen.lds.S | 3 +++
> >  1 file changed, 3 insertions(+)
>
> This is lacking your own S-o-b.
>
> > --- a/xen/arch/x86/xen.lds.S
> > +++ b/xen/arch/x86/xen.lds.S
> > @@ -57,6 +57,9 @@ SECTIONS
> >    __image_base__ = .;
> >  #else
> >    . = __image_base__;
> > +  /DISCARD/ : {
> > +    *(.text.header)
> > +  }
> >  #endif
>
> We already have DISCARD_SECTIONS, so I think it needs clarifying why that
> can't be used / extended.
>

Yes, this can be done that way. Roger, do you agree on this ?

> Jan

Frediano