Re: [edk2-devel] [PATCH v2 0/6] Fix PEI Core issue during TemporaryRamMigration

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On Wed, 10 Apr 2019 at 11:28, Laszlo Ersek <lersek@redhat.com> wrote:
>
> On 04/10/19 18:41, Ard Biesheuvel wrote:
> > On Wed, 10 Apr 2019 at 01:41, Jordan Justen <jordan.l.justen@intel.com> wrote:
> >>
> >> https://github.com/jljusten/edk2.git temp-ram-support-v2
> >>
> >> https://github.com/jljusten/edk2/commits/temp-ram-support-v2
> >>
> >> v2:
> >>  * Add AARCH64 and ARM assembly
> >
> > Hi Jordan,
> >
> > I'm not sure I'm following the reasoning behind this. Does this fix an
> > issue we currently have on ARM systems?
>
> IIUC, the PEI Core can only be updated to use the "safe path" (= the
> assembly path) on IA32/X64 if that path (= the assembly path) *exists*
> regardless of architecture.
>
> This is anyway my understanding of the last commit message in the series.
>
> I can't evaluate whether the problem statement, in the first commit
> message in the series, would ever turn into an actual issue on
> ARM/AARCH64, dependent on toolchain. On IA32/X64, we've seen examples
> (although none of those have bit me personally), and AIUI the issue
> could theoretically apply to all arches (again, dependent on toolchain).
>
> (Apologies if I've only increased the confusion with this -- but at
> least it could help me improve my own understanding.)
>
> > And how did you build and/or test OVMF for ARM?
>
> Hmmm, I'm unsure where this question / implication comes from. AIUI, the
> new ARM/AARCH64 assembly is automatically put to use if you run the PEI
> Core -- as part of a firmware platform that uses temp RAM migration --
> on ARM/AARCH64.
>

OK, seems like I'm the one creating confusion here. These are
MdeModulePkg patches not OvmfPkg patches, and I noticed some other
patches by Jordan adding ARM/AARCH64 build support to OVMF.

I will put the assembly patches on my to-review list, but it may take
me a couple of days to get to them.