[PATCH v2 04/15] efi/libstub: Add a general way to get symbols from the vmlinux into zboot

[Ard Biesheuvel]

On Tue, 3 Nov 2026, at 17:01, Jason Gunthorpe wrote:
> On Fri, Oct 02, 2026 at 08:31:41PM -0300, Jason Gunthorpe wrote:
>> Currently the zboot stub has no access to symbols in the vmlinux. In
>> contrast x86 has a voffsets.h header that allows the stub to know whatever
>> symbols it wants for the decompressed image. ARM DRTM needs another 4
>> symbol locations to work, and it also wants to compile the DRTM libstub
>> code once and have it work in both zboot and embedded.
>> 
>> The current solution in arm is "code_size" from commit 45dd403da851
>> ("efi/zboot: arm64: Inject kernel code size symbol into the zboot
>> payload"). This is neat, but it makes the zboot and embedded cases
>> work differently.
>> 
>> The x86 voffsets.h approach is also nice, but it can only work in zboot
>> since it relies on 'nm vmlinux' to extract the locations. That's a
>> circular dependency for the embedded stub.
>
> Ard,
>
> Did you have any further thoughts on this patch? Did the sketch you
> showed me at LPC turn into anything?
>

I will get back to you before the end of the week.