Re: [PATCH v6 1/8] xen: reuse x86 EFI stub functions for Arm

[Jan Beulich <jbeulich@suse.com>]

On 10.06.2022 07:53, Wei Chen wrote:
> --- 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
> --- a/xen/arch/arm/efi/Makefile
> +++ b/xen/arch/arm/efi/Makefile
> @@ -1,4 +1,12 @@
>  include $(srctree)/common/efi/efi-common.mk
>  
> +ifeq ($(CONFIG_ARM_EFI),y)
>  obj-y += $(EFIOBJ-y)
>  obj-$(CONFIG_ACPI) +=  efi-dom0.init.o
> +else
> +# Add stub.o to EFIOBJ-y to re-use the clean-files in
> +# efi-common.mk. Otherwise the link of stub.c in arm/efi
> +# will not be cleaned in "make clean".
> +EFIOBJ-y += stub.o
> +obj-y += stub.o
> +endif

This has caused

ld: warning: arch/arm/efi/built_in.o uses 2-byte wchar_t yet the output is to use 4-byte wchar_t; use of wchar_t values across objects may fail

for the 32-bit Arm build that I keep doing every once in a while, with
(if it matters) GNU ld 2.38. I guess you will want to consider building
all of Xen with -fshort-wchar, or to avoid building stub.c with that
option.

Jan