RE: [PATCH v2 02/40] xen/arm: make ARM_EFI selectable for Arm64

[Wei Chen <Wei.Chen@xxxxxxx>]

Hi Julien,

> -----Original Message-----
> From: Julien Grall <julien@xxxxxxx>
> Sent: 2023年1月18日 7:09
> To: Penny Zheng <Penny.Zheng@xxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Wei Chen <Wei.Chen@xxxxxxx>; Stefano Stabellini
> <sstabellini@xxxxxxxxxx>; Bertrand Marquis <Bertrand.Marquis@xxxxxxx>;
> Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>
> Subject: Re: [PATCH v2 02/40] xen/arm: make ARM_EFI selectable for Arm64
> 
> Hi Penny,
> 
> On 13/01/2023 05:28, Penny Zheng wrote:
> > From: Wei Chen <wei.chen@xxxxxxx>
> >
> > Currently, ARM_EFI will mandatorily selected by Arm64.
> > Even if the user knows for sure that their images will not
> > start in the EFI environment, they can't disable the EFI
> > support for Arm64. This means there will be about 3K lines
> > unused code in their images.
> >
> > So in this patch, we make ARM_EFI selectable for Arm64, and
> > based on that, we can use CONFIG_ARM_EFI to gate the EFI
> > specific code in head.S for those images that will not be
> > booted in EFI environment.
> >
> > Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
> 
> Your signed-off-by is missing.
> 
> > ---
> > v1 -> v2:
> > 1. New patch
> > ---
> >   xen/arch/arm/Kconfig      | 10 ++++++++--
> >   xen/arch/arm/arm64/head.S | 15 +++++++++++++--
> >   2 files changed, 21 insertions(+), 4 deletions(-)
> >
> > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> > index 239d3aed3c..ace7178c9a 100644
> > --- a/xen/arch/arm/Kconfig
> > +++ b/xen/arch/arm/Kconfig
> > @@ -7,7 +7,6 @@ config ARM_64
> >     def_bool y
> >     depends on !ARM_32
> >     select 64BIT
> > -   select ARM_EFI
> >     select HAS_FAST_MULTIPLY
> >
> >   config ARM
> > @@ -37,7 +36,14 @@ config ACPI
> >       an alternative to device tree on ARM64.
> >
> >   config ARM_EFI
> > -   bool
> > +   bool "UEFI boot service support"
> > +   depends on ARM_64
> > +   default y
> > +   help
> > +     This option provides support for boot services through
> > +     UEFI firmware. A UEFI stub is provided to allow Xen to
> > +     be booted as an EFI application. This is only useful for
> > +     Xen that may run on systems that have UEFI firmware.
> 
> I would drop the last sentence as this is implied with the rest of the
> paragraph.
> 

Ok.

Cheers,
Wei Chen

> Cheers,
> 
> --
> Julien Grall