Re: [PATCH 16/16] Add config EFI_STUB for ARM to Kconfig

Grant Likely
2013-08-30T11:17:10Z

On Tue, 13 Aug 2013 10:37:13 -0700, Roy Franz <roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> On Tue, Aug 13, 2013 at 6:18 AM, Dave Martin <Dave.Martin-5wv7dgnIgG8@public.gmane.org> wrote:
> > On Fri, Aug 09, 2013 at 04:26:17PM -0700, Roy Franz wrote:
> >> Signed-off-by: Roy Franz <roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> >> ---
> >> arch/arm/Kconfig | 11 +++++++++++
> >> 1 file changed, 11 insertions(+)
> >>
> >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> >> index 43594d5..8607d03 100644
> >> --- a/arch/arm/Kconfig
> >> +++ b/arch/arm/Kconfig
> >> @@ -1805,6 +1805,17 @@ config UACCESS_WITH_MEMCPY
> >> However, if the CPU data cache is using a write-allocate mode,
> >> this option is unlikely to provide any performance gain.
> >>
> >> +config EFI_STUB
> >> + bool "EFI stub support"
> >> + depends on EFI
> >
> > && !CPU_BIG_ENDIAN, in case you didn't get around to that.
> >
> > Sooner or later, someone may try to fix that, so there should be a
> > comment somewhere explaining what is broken for BE.
> >
> > Either in efi-stub.c or in the commit message accompanying this patch, I
> > guess.
> >
> EFI will be !CPU_BIG_ENDIAN, so we will get the dependency
> transitively through EFI.
> That said, I think it may be better to have both be explicitly
> !CPU_BIG_ENDIAN, as even
> though the underlying reasons are the same (EFI services calls being
> little endian), both
> the stub and runtime services would need to be fixed to enable the
> stub to run in BE mode.
> I'll make this explicit in the stub Kconfig, and add a comment by the
> PE/COFF magic number
> regarding the LE requirement.

Actually, not true! Steve McIntyre is currently doing some of the BE
porting work on TC2 running UEFI. Eventually he will need this.

g.