[PATCH v2] powerpc/boot: pass CONFIG options in a simpler and more robust way

From: Masahiro Yamada
Date: Mon May 13 2019 - 10:19:29 EST


Commit 5e9dcb6188a4 ("powerpc/boot: Expose Kconfig symbols to wrapper")
was wrong, but commit e41b93a6be57 ("powerpc/boot: Fix build failures
with -j 1") was also wrong.

The correct dependency is:

$(obj)/serial.o: $(obj)/autoconf.h

However, I do not see the reason why we need to copy autoconf.h to
arch/power/boot/. Nor do I see consistency in the way of passing
CONFIG options.

decompress.c references CONFIG_KERNEL_GZIP and CONFIG_KERNEL_XZ, which
are passed via the command line.

serial.c includes autoconf.h to reference a couple of CONFIG options,
but this is fragile because we often forget to include "autoconf.h"
from source files.

In fact, it is already broken.

ppc_asm.h references CONFIG_PPC_8xx, but utils.S is not given any way
to access CONFIG options. So, CONFIG_PPC_8xx is never defined here.

Pass $(LINUXINCLUDE) to make sure CONFIG options are accessible from
all .c and .S files in arch/powerpc/boot/.

I also removed the -traditional flag to make include/linux/kconfig.h
work. This flag makes the preprocessor imitate the behavior of the
pre-standard C compiler, but I do not understand why it is necessary.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2:
- reword commit log

arch/powerpc/boot/.gitignore | 2 --
arch/powerpc/boot/Makefile | 14 +++-----------
arch/powerpc/boot/serial.c | 1 -
3 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/boot/.gitignore b/arch/powerpc/boot/.gitignore
index 32034a0c..6610665 100644
--- a/arch/powerpc/boot/.gitignore
+++ b/arch/powerpc/boot/.gitignore
@@ -44,5 +44,3 @@ fdt_sw.c
fdt_wip.c
libfdt.h
libfdt_internal.h
-autoconf.h
-
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 73d1f35..b8a82be 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -20,9 +20,6 @@

all: $(obj)/zImage

-compress-$(CONFIG_KERNEL_GZIP) := CONFIG_KERNEL_GZIP
-compress-$(CONFIG_KERNEL_XZ) := CONFIG_KERNEL_XZ
-
ifdef CROSS32_COMPILE
BOOTCC := $(CROSS32_COMPILE)gcc
BOOTAR := $(CROSS32_COMPILE)ar
@@ -34,7 +31,7 @@ endif
BOOTCFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \
-pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
- -D$(compress-y)
+ $(LINUXINCLUDE)

ifdef CONFIG_PPC64_BOOT_WRAPPER
BOOTCFLAGS += -m64
@@ -51,7 +48,7 @@ BOOTCFLAGS += -mlittle-endian
BOOTCFLAGS += $(call cc-option,-mabi=elfv2)
endif

-BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
+BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -nostdinc

BOOTARFLAGS := -cr$(KBUILD_ARFLAGS)

@@ -202,14 +199,9 @@ $(obj)/empty.c:
$(obj)/zImage.coff.lds $(obj)/zImage.ps3.lds : $(obj)/%: $(srctree)/$(src)/%.S
$(Q)cp $< $@

-$(srctree)/$(src)/serial.c: $(obj)/autoconf.h
-
-$(obj)/autoconf.h: $(obj)/%: $(objtree)/include/generated/%
- $(Q)cp $< $@
-
clean-files := $(zlib-) $(zlibheader-) $(zliblinuxheader-) \
$(zlib-decomp-) $(libfdt) $(libfdtheader) \
- autoconf.h empty.c zImage.coff.lds zImage.ps3.lds zImage.lds
+ empty.c zImage.coff.lds zImage.ps3.lds zImage.lds

quiet_cmd_bootcc = BOOTCC $@
cmd_bootcc = $(BOOTCC) -Wp,-MD,$(depfile) $(BOOTCFLAGS) -c -o $@ $<
diff --git a/arch/powerpc/boot/serial.c b/arch/powerpc/boot/serial.c
index b0491b8..9457863 100644
--- a/arch/powerpc/boot/serial.c
+++ b/arch/powerpc/boot/serial.c
@@ -18,7 +18,6 @@
#include "stdio.h"
#include "io.h"
#include "ops.h"
-#include "autoconf.h"

static int serial_open(void)
{
--
2.7.4