[PATCH 00/32] arm: Support building as an EFI app

[Simon Glass]

Hi Heinrich,

On Thu, 6 Feb 2025 at 03:56, Heinrich Schuchardt <xypron.glpk at gmx.de> wrote:
>
> On 2/3/25 18:41, Simon Glass wrote:
> > The original x86 EFI-app was written back in 2015, about a year before
> > the EFI-loader was introduced. At that point, ARM mostly used U-Boot and
> > FIT (Flat Image Tree).
> >
> > Today, sadly, there are a few efforts to re-invent FIT poorly, to cater
> > to more primitive boot-environments than U-Boot. One justification for
> > this re-invetion has been that EDK2 did not support FIT.
> >
> > EDK2 does now support FIT but only for the firmware stage. Even then,
> > vendors tend to use their own forks, so any new features are slow to
> > make it into the market.
> >
> > EDK2 also supports the ext4 filesystem, but many devices don't include
> > that feature, so most distros make use of FAT for storing their boot
> > files. Since FAT is not journalled, it is not particularly reliable in
> > the face of reset, power failure, etc.
> >
> > As an interim measure, we can use U-Boot as an EFI app running on top of
> > whatever EDK2 fork is in use. This allows use of modern features such as
> > FIT and filesystems other than FAT. So far this only supports x86, but
> > recent ARM laptops are making use of EFI too.
> >
> > So this series adds an EFI app for 64-bit ARM.
> >
> > Note: Since U-Boot does not support EFI's GOP 'blt-only' mode, the
> > vidconsole does not operate, but it can still be used, since EDK2
> > handles drawing instead of U-Boot. As a result, the U-Boot logo is not
> > shown.
>
> Thank you Simon for going through this effort to generalize the EFI app.

You're welcome.

>
> The EFI app should build on all EFI architecture. Will you add RISC-V
> support, too?

Not in this series, but perhaps later.

Regards,
Simon