[PATCH v4 4/5] efi: Reserve some memory for initial use

[Ilias Apalodimas]

Hi Tom

On Sat, 12 Oct 2024 at 04:27, Tom Rini <trini at konsulko.com> wrote:
>
> On Sat, Oct 12, 2024 at 12:01:54AM +0200, Heinrich Schuchardt wrote:
> >
> >
> > Am 11. Oktober 2024 23:21:25 MESZ schrieb Simon Glass <sjg at chromium.org>:
> > >The 'point of cooperation' is where U-Boot starts allowing EFI to use
> > >memory outside of the U-Boot region. Until that point, it is desirable
> > >to keep more below U-Boot free for loading images.
> > >
> > >Reserve a small region for this purpose.
> >
> > Your commit message provides no clue why this should be needed.
>
> The alternative here would be a patch to doc/develop/memory.rst saying
> something to the effect of:
>
> EFI pool allocations start at ... U-Boot stack pointer +
> CONFIG_STACK_SIZE and grow downwards from there. These are done by ... a
> brief description of how the pool allocations work ... Nominally, this
> will extend for only a few pages worth of memory but depending on
> requests made by EFI applications can grow larger. All of this is
> covered by the LMB that covers U-Boot itself and is considered part of
> the U-Boot memory map. It may be broken down in to further detail to the
> memory map provided to the OS, in some cases.

I'll send a patch to update that next week. Perhaps even fold it in
the LMB series

Thanks
/Ilias
>
> --
> Tom