Re: [PATCH v2 03/10] xen/arm: add CONFIG_ARM_EFI to stub EFI API

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 21 Apr 2022, Wei Chen wrote:
> Hi Stefano,
> 
> On 2022/4/21 8:25, Stefano Stabellini wrote:
> > On Mon, 18 Apr 2022, Wei Chen wrote:
> > > x86 is using compiler feature testing to decide EFI
> > > build enable or not. When EFI build is disabled, x86
> > > will use a efi/stub.c file to replace efi/runtime.c
> > > for build objects. Following this idea, we introduce
> > > a stub file for Arm, but use CONFIG_ARM_EFI to decide
> > > EFI build enable or not.
> > > 
> > > Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
> > > ---
> > > v1 -> v2:
> > > 1. Use CONFIG_ARM_EFI to replace CONFIG_EFI
> > > 2. Remove help text and make CONFIG_ARM_EFI invisible.
> > > 3. Merge one following patch:
> > >     xen/arm: introduce a stub file for non-EFI architectures
> > > 4. Use the common stub.c instead of creating new one.
> > > ---
> > >   xen/arch/arm/Kconfig      | 5 +++++
> > >   xen/arch/arm/Makefile     | 2 +-
> > >   xen/arch/arm/efi/Makefile | 5 +++++
> > >   3 files changed, 11 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> > > index ecfa6822e4..5f1b0121b0 100644
> > > --- a/xen/arch/arm/Kconfig
> > > +++ b/xen/arch/arm/Kconfig
> > > @@ -6,6 +6,7 @@ config ARM_64
> > >           def_bool y
> > >           depends on !ARM_32
> > >           select 64BIT
> > > + select ARM_EFI
> > >           select HAS_FAST_MULTIPLY
> > >     config ARM
> > > @@ -33,6 +34,10 @@ config ACPI
> > >             Advanced Configuration and Power Interface (ACPI) support for 
> > > Xen is
> > >             an alternative to device tree on ARM64.
> > >   +config ARM_EFI
> > > + bool
> > > + depends on ARM_64
> > 
> > As ARM_EFI is selected by ARM_64 and it cannot be enable via a menu (it
> > is hidden) there is no need for the "depends" line here
> > 
> 
> Ok, I will remove it.
> 
> > 
> > >   config GICV3
> > >           bool "GICv3 driver"
> > >           depends on ARM_64 && !NEW_VGIC
> > > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> > > index 1d862351d1..bb7a6151c1 100644
> > > --- a/xen/arch/arm/Makefile
> > > +++ b/xen/arch/arm/Makefile
> > > @@ -1,6 +1,5 @@
> > >   obj-$(CONFIG_ARM_32) += arm32/
> > >   obj-$(CONFIG_ARM_64) += arm64/
> > > -obj-$(CONFIG_ARM_64) += efi/
> > >   obj-$(CONFIG_ACPI) += acpi/
> > >   obj-$(CONFIG_HAS_PCI) += pci/
> > >   ifneq ($(CONFIG_NO_PLAT),y)
> > > @@ -20,6 +19,7 @@ obj-y += domain.o
> > >   obj-y += domain_build.init.o
> > >   obj-y += domctl.o
> > >   obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
> > > +obj-y += efi/
> > >   obj-y += gic.o
> > >   obj-y += gic-v2.o
> > >   obj-$(CONFIG_GICV3) += gic-v3.o
> > > diff --git a/xen/arch/arm/efi/Makefile b/xen/arch/arm/efi/Makefile
> > > index 4313c39066..75ef180233 100644
> > > --- a/xen/arch/arm/efi/Makefile
> > > +++ b/xen/arch/arm/efi/Makefile
> > > @@ -1,4 +1,9 @@
> > >   include $(srctree)/common/efi/efi-common.mk
> > >   +ifeq ($(CONFIG_ARM_EFI),y)
> > >   obj-y += $(EFIOBJ-y)
> > >   obj-$(CONFIG_ACPI) +=  efi-dom0.init.o
> > > +else
> > > +EFIOBJ-y += stub.o
> > > +obj-y += stub.o
> > 
> > The change to EFIOBJ-y is not needed here as EFIOBJ-y is not used.
> > Only obj-y += stub.o should be enough
> > 
> 
> I add stub.o to EFIOBJ-y that's because I want to use the clean-files
> in efi-common.mk. Otherwise the link of stub.c in arm/efi will not
> be cleaned in "make clean".

I see. Makes sense.