[PATCH v2 1/4] net: wan: wanxl: use allow to pass CROSS_COMPILE_M68k for rebuilding firmware

[PATCH v2 1/4] net: wan: wanxl: use allow to pass CROSS_COMPILE_M68k for rebuilding firmware

[Masahiro Yamada]

As far as I understood from the Kconfig help text, this build rule is
used to rebuild the driver firmware, which runs on an old m68k-based
chip. So, you need m68k tools for the firmware rebuild.

wanxl.c is a PCI driver, but CONFIG_M68K does not select CONFIG_HAVE_PCI.
So, you cannot enable CONFIG_WANXL_BUILD_FIRMWARE for ARCH=m68k. In other
words, ifeq ($(ARCH),m68k) is false here.

I am keeping the dead code for now, but rebuilding the firmware requires
'as68k' and 'ld68k', which I do not have in hand.

Instead, the kernel.org m68k GCC [1] successfully built it.

Allowing a user to pass in CROSS_COMPILE_M68K= is handier.

[1] https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/9.2.0/x86_64-gcc-9.2.0-nolibc-m68k-linux.tar.xz

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v2:
  - New patch

 drivers/net/wan/Kconfig  |  2 +-
 drivers/net/wan/Makefile | 12 ++++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig
index 4530840e15ef..dbc0e3f7a3e2 100644
--- a/drivers/net/wan/Kconfig
+++ b/drivers/net/wan/Kconfig
@@ -200,7 +200,7 @@ config WANXL_BUILD_FIRMWARE
 	depends on WANXL && !PREVENT_FIRMWARE_BUILD
 	help
 	  Allows you to rebuild firmware run by the QUICC processor.
-	  It requires as68k, ld68k and hexdump programs.
+	  It requires m68k toolchains and hexdump programs.
 
 	  You should never need this option, say N.
 
diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile
index 701f5d2fe3b6..995277c657a1 100644
--- a/drivers/net/wan/Makefile
+++ b/drivers/net/wan/Makefile
@@ -40,17 +40,17 @@ $(obj)/wanxl.o:	$(obj)/wanxlfw.inc
 
 ifeq ($(CONFIG_WANXL_BUILD_FIRMWARE),y)
 ifeq ($(ARCH),m68k)
-  AS68K = $(AS)
-  LD68K = $(LD)
+  M68KAS = $(AS)
+  M68KLD = $(LD)
 else
-  AS68K = as68k
-  LD68K = ld68k
+  M68KAS = $(CROSS_COMPILE_M68K)as
+  M68KLD = $(CROSS_COMPILE_M68K)ld
 endif
 
 quiet_cmd_build_wanxlfw = BLD FW  $@
       cmd_build_wanxlfw = \
-	$(CPP) -D__ASSEMBLY__ -Wp,-MD,$(depfile) -I$(srctree)/include/uapi $< | $(AS68K) -m68360 -o $(obj)/wanxlfw.o; \
-	$(LD68K) --oformat binary -Ttext 0x1000 $(obj)/wanxlfw.o -o $(obj)/wanxlfw.bin; \
+	$(CPP) -D__ASSEMBLY__ -Wp,-MD,$(depfile) -I$(srctree)/include/uapi $< | $(M68KAS) -m68360 -o $(obj)/wanxlfw.o; \
+	$(M68KLD) --oformat binary -Ttext 0x1000 $(obj)/wanxlfw.o -o $(obj)/wanxlfw.bin; \
 	hexdump -ve '"\n" 16/1 "0x%02X,"' $(obj)/wanxlfw.bin | sed 's/0x  ,//g;1s/^/static const u8 firmware[]={/;$$s/,$$/\n};\n/' >$(obj)/wanxlfw.inc; \
 	rm -f $(obj)/wanxlfw.bin $(obj)/wanxlfw.o
 
-- 
2.17.1

[PATCH v2 2/4] net: wan: wanxl: use $(M68KCC) instead of $(M68KAS) for rebuilding firmware

[Masahiro Yamada]

The firmware source, wanxlfw.S, is currently compiled by the combo of
$(CPP) and $(M68KAS). This is not what we usually do for compiling *.S
files. In fact, this Makefile is the only user of $(AS) in the kernel
build.

Instead of combining $(CPP) and (AS) from different tool sets, using
$(M68KCC) as an assembler driver is simpler, and saner.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v2: None

 drivers/net/wan/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile
index 995277c657a1..cf7a0a65aae8 100644
--- a/drivers/net/wan/Makefile
+++ b/drivers/net/wan/Makefile
@@ -40,16 +40,16 @@ $(obj)/wanxl.o:	$(obj)/wanxlfw.inc
 
 ifeq ($(CONFIG_WANXL_BUILD_FIRMWARE),y)
 ifeq ($(ARCH),m68k)
-  M68KAS = $(AS)
+  M68KCC = $(CC)
   M68KLD = $(LD)
 else
-  M68KAS = $(CROSS_COMPILE_M68K)as
+  M68KCC = $(CROSS_COMPILE_M68K)gcc
   M68KLD = $(CROSS_COMPILE_M68K)ld
 endif
 
 quiet_cmd_build_wanxlfw = BLD FW  $@
       cmd_build_wanxlfw = \
-	$(CPP) -D__ASSEMBLY__ -Wp,-MD,$(depfile) -I$(srctree)/include/uapi $< | $(M68KAS) -m68360 -o $(obj)/wanxlfw.o; \
+	$(M68KCC) -D__ASSEMBLY__ -Wp,-MD,$(depfile) -I$(srctree)/include/uapi -c -o $(obj)/wanxlfw.o $<; \
 	$(M68KLD) --oformat binary -Ttext 0x1000 $(obj)/wanxlfw.o -o $(obj)/wanxlfw.bin; \
 	hexdump -ve '"\n" 16/1 "0x%02X,"' $(obj)/wanxlfw.bin | sed 's/0x  ,//g;1s/^/static const u8 firmware[]={/;$$s/,$$/\n};\n/' >$(obj)/wanxlfw.inc; \
 	rm -f $(obj)/wanxlfw.bin $(obj)/wanxlfw.o
-- 
2.17.1

[PATCH v2 3/4] net: wan: wanxl: refactor the firmware rebuild rule

[Masahiro Yamada]

Split the big recipe into 3 stages, compile, link, and hexdump.

After this commit, the build log with CONFIG_WANXL_BUILD_FIRMWARE
will look like this:

  M68KAS  drivers/net/wan/wanxlfw.o
  M68KLD  drivers/net/wan/wanxlfw.bin
  BLDFW   drivers/net/wan/wanxlfw.inc
  CC [M]  drivers/net/wan/wanxl.o

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

Changes in v2: None

 drivers/net/wan/Makefile | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile
index cf7a0a65aae8..380271a011e4 100644
--- a/drivers/net/wan/Makefile
+++ b/drivers/net/wan/Makefile
@@ -47,14 +47,23 @@ else
   M68KLD = $(CROSS_COMPILE_M68K)ld
 endif
 
-quiet_cmd_build_wanxlfw = BLD FW  $@
-      cmd_build_wanxlfw = \
-	$(M68KCC) -D__ASSEMBLY__ -Wp,-MD,$(depfile) -I$(srctree)/include/uapi -c -o $(obj)/wanxlfw.o $<; \
-	$(M68KLD) --oformat binary -Ttext 0x1000 $(obj)/wanxlfw.o -o $(obj)/wanxlfw.bin; \
-	hexdump -ve '"\n" 16/1 "0x%02X,"' $(obj)/wanxlfw.bin | sed 's/0x  ,//g;1s/^/static const u8 firmware[]={/;$$s/,$$/\n};\n/' >$(obj)/wanxlfw.inc; \
-	rm -f $(obj)/wanxlfw.bin $(obj)/wanxlfw.o
-
-$(obj)/wanxlfw.inc:	$(src)/wanxlfw.S
-	$(call if_changed_dep,build_wanxlfw)
-targets += wanxlfw.inc
+quiet_cmd_build_wanxlfw = BLDFW   $@
+      cmd_build_wanxlfw = hexdump -ve '"\n" 16/1 "0x%02X,"' $< | \
+	sed 's/0x  ,//g;1s/^/static const u8 firmware[]={/;$$s/,$$/\n};\n/' > $@
+
+$(obj)/wanxlfw.inc: $(obj)/wanxlfw.bin FORCE
+	$(call if_changed,build_wanxlfw)
+
+quiet_cmd_m68kld_bin_o = M68KLD  $@
+      cmd_m68kld_bin_o = $(M68KLD) --oformat binary -Ttext 0x1000 $< -o $@
+
+$(obj)/wanxlfw.bin: $(obj)/wanxlfw.o FORCE
+	$(call if_changed,m68kld_bin_o)
+
+quiet_cmd_m68kas_o_S = M68KAS  $@
+      cmd_m68kas_o_S = $(M68KCC) -D__ASSEMBLY__ -Wp,-MD,$(depfile) -I$(srctree)/include/uapi -c -o $@ $<
+
+$(obj)/wanxlfw.o: $(src)/wanxlfw.S FORCE
+	$(call if_changed_dep,m68kas_o_S)
 endif
+targets += wanxlfw.inc wanxlfw.bin wanxlfw.o
-- 
2.17.1

[PATCH v2 4/4] kbuild: remove AS variable

[Masahiro Yamada]

As commit 5ef872636ca7 ("kbuild: get rid of misleading $(AS) from
documents") noted, we rarely use $(AS) directly in the kernel build.

Now that the only/last user of $(AS) in drivers/net/wan/Makefile was
converted to $(CC), $(AS) is no longer used in the build process.

You can still pass in AS=clang, which is just a switch to turn on
the LLVM integrated assembler.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
---

Changes in v2:
  - Fix breakage of CC=clang build

 Makefile | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index fcec84681e4e..2e12fa1cc8f3 100644
--- a/Makefile
+++ b/Makefile
@@ -405,7 +405,6 @@ KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 
 # Make variables (CC, etc...)
-AS		= $(CROSS_COMPILE)as
 LD		= $(CROSS_COMPILE)ld
 CC		= $(CROSS_COMPILE)gcc
 CPP		= $(CC) -E
@@ -535,7 +534,7 @@ endif
 ifneq ($(GCC_TOOLCHAIN),)
 CLANG_FLAGS	+= --gcc-toolchain=$(GCC_TOOLCHAIN)
 endif
-ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
+ifeq ($(if $(AS),$(shell $(AS) --version 2>&1 | head -n 1 | grep clang)),)
 CLANG_FLAGS	+= -no-integrated-as
 endif
 CLANG_FLAGS	+= -Werror=unknown-warning-option
-- 
2.17.1

Re: [PATCH v2 4/4] kbuild: remove AS variable

[Masahiro Yamada]

On Thu, Mar 26, 2020 at 2:58 PM Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> As commit 5ef872636ca7 ("kbuild: get rid of misleading $(AS) from
> documents") noted, we rarely use $(AS) directly in the kernel build.
>
> Now that the only/last user of $(AS) in drivers/net/wan/Makefile was
> converted to $(CC), $(AS) is no longer used in the build process.
>
> You can still pass in AS=clang, which is just a switch to turn on
> the LLVM integrated assembler.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>


I forgot to remove the export.




@@ -472,7 +471,7 @@ KBUILD_LDFLAGS :=
 GCC_PLUGINS_CFLAGS :=
 CLANG_FLAGS :=

-export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS
CROSS_COMPILE AS LD CC
+export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS
CROSS_COMPILE LD CC
 export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE READELF PAHOLE LEX
YACC AWK INSTALLKERNEL
 export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE





> ---
>
> Changes in v2:
>   - Fix breakage of CC=clang build
>
>  Makefile | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/Makefile b/Makefile
> index fcec84681e4e..2e12fa1cc8f3 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -405,7 +405,6 @@ KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
>  KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
>
>  # Make variables (CC, etc...)
> -AS             = $(CROSS_COMPILE)as
>  LD             = $(CROSS_COMPILE)ld
>  CC             = $(CROSS_COMPILE)gcc
>  CPP            = $(CC) -E
> @@ -535,7 +534,7 @@ endif
>  ifneq ($(GCC_TOOLCHAIN),)
>  CLANG_FLAGS    += --gcc-toolchain=$(GCC_TOOLCHAIN)
>  endif
> -ifeq ($(shell $(AS) --version 2>&1 | head -n 1 | grep clang),)
> +ifeq ($(if $(AS),$(shell $(AS) --version 2>&1 | head -n 1 | grep clang)),)
>  CLANG_FLAGS    += -no-integrated-as
>  endif
>  CLANG_FLAGS    += -Werror=unknown-warning-option
> --
> 2.17.1
>
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-- 
Best Regards
Masahiro Yamada