Re: [Qemu-devel] [PATCH V7 1/4] rules: Move cross compilation auto detection functions to rules.mak

[Laurent Vivier]

On 28/02/2018 19:02, Wei Huang wrote:
> This patch moves the auto detection functions for cross compilation from
> roms/Makefile to rules.mak. So the functions can be shared among Makefiles
> in QEMU.
> 
> Signed-off-by: Wei Huang <address@hidden>
> Reviewed-by: Andrew Jones <address@hidden>
> ---
>  roms/Makefile | 24 +++++++-----------------
>  rules.mak     | 15 +++++++++++++++
>  2 files changed, 22 insertions(+), 17 deletions(-)
> 
> diff --git a/roms/Makefile b/roms/Makefile
> index b5e5a69e91..e972c65333 100644
> --- a/roms/Makefile
> +++ b/roms/Makefile
> @@ -21,23 +21,6 @@ pxe-rom-virtio   efi-rom-virtio   : DID := 1000
>  pxe-rom-vmxnet3  efi-rom-vmxnet3  : VID := 15ad
>  pxe-rom-vmxnet3  efi-rom-vmxnet3  : DID := 07b0
>  
> -#
> -# cross compiler auto detection
> -#
> -path := $(subst :, ,$(PATH))
> -system := $(shell uname -s | tr "A-Z" "a-z")
> -
> -# first find cross binutils in path
> -find-cross-ld = $(firstword $(wildcard $(patsubst 
> %,%/$(1)-*$(system)*-ld,$(path))))
> -# then check we have cross gcc too
> -find-cross-gcc = $(firstword $(wildcard $(patsubst %ld,%gcc,$(call 
> find-cross-ld,$(1)))))
> -# finally strip off path + toolname so we get the prefix
> -find-cross-prefix = $(subst gcc,,$(notdir $(call find-cross-gcc,$(1))))
> -
> -powerpc64_cross_prefix := $(call find-cross-prefix,powerpc64)
> -powerpc_cross_prefix := $(call find-cross-prefix,powerpc)
> -x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
> -
>  # tag our seabios builds
>  SEABIOS_EXTRAVERSION="-prebuilt.qemu-project.org"
>  
> @@ -66,6 +49,13 @@ default:
>       @echo "  skiboot        -- update skiboot.lid"
>       @echo "  u-boot.e500    -- update u-boot.e500"
>  
> +SRC_PATH=..
> +include $(SRC_PATH)/rules.mak
> +
> +powerpc64_cross_prefix := $(call find-cross-prefix,powerpc64)
> +powerpc_cross_prefix := $(call find-cross-prefix,powerpc)
> +x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
> +
>  bios: build-seabios-config-seabios-128k build-seabios-config-seabios-256k
>       cp seabios/builds/seabios-128k/bios.bin ../pc-bios/bios.bin
>       cp seabios/builds/seabios-256k/bios.bin ../pc-bios/bios-256k.bin
> diff --git a/rules.mak b/rules.mak
> index 6e943335f3..ef8adee3f8 100644
> --- a/rules.mak
> +++ b/rules.mak
> @@ -62,6 +62,21 @@ expand-objs = $(strip $(sort $(filter %.o,$1)) \
>                    $(foreach o,$(filter %.mo,$1),$($o-objs)) \
>                    $(filter-out %.o %.mo,$1))
>  
> +# Cross compilation auto detection. Use find-cross-prefix to detect the
> +# target archtecture's prefix, and then append it to the build tool or pass
> +# it to CROSS_COMPILE directly. Here is one example:
> +#      x86_64_cross_prefix := $(call find-cross-prefix,x86_64)
> +#      $(x86_64_cross_prefix)gcc -c test.c -o test.o
> +#      make -C testdir CROSS_COMPILE=$(x86_64_cross_prefix)
> +cross-search-path := $(subst :, ,$(PATH))
> +cross-host-system := $(shell uname -s | tr "A-Z" "a-z")
> +
> +find-cross-ld = $(firstword $(wildcard $(patsubst \
> +                    
> %,%/$(1)-*$(cross-host-system)*-ld,$(cross-search-path))))
> +find-cross-gcc = $(firstword $(wildcard \
> +                    $(patsubst %ld,%gcc,$(call find-cross-ld,$(1)))))
> +find-cross-prefix = $(subst gcc,,$(notdir $(call find-cross-gcc,$(1))))
> +
>  %.o: %.c
>       $(call quiet-command,$(CC) $(QEMU_LOCAL_INCLUDES) $(QEMU_INCLUDES) \
>              $(QEMU_CFLAGS) $(QEMU_DGFLAGS) $(CFLAGS) $(address@hidden) \
> 

With this patch, "make slof" fails:

  git submodule init roms/SLOF
  git submodule update roms/SLOF
  cd roms
  make slof
...
make[4]: Entering directory
'/home/lvivier/Projects/qemu-upstream/roms/SLOF/lib/libnvram'
        [CC]    Makefile.dep
powerpc64-linux-gnu-ar: nvram.o: No such file or directory
make[4]: *** [Makefile:31: ../libnvram.a] Error 1

Perhaps rules.mak defines values inherited by SLOF makefiles that are
incompatible?

Thanks,
Laurent