Syslinux - Jun 2017 - [PATCH v2 0/4] Allow cross-building of syslinux

Hi together,

this is the second version of my cross-compilation patch serie. I'm sending
it in the hope to get an honest review, and possibly see the patches integrated
upstream.

Those patches allow to build syslinux using a toolchain different from the host
one by explicitely using the host toolchain for the utilities that are required
at build-time / on the build machine.

I am using the XX_FOR_BUILD environment variables for that, which is a common
practice for projects using autoconf.

Those patches are originally written for the buildroot project, and you can
browse them anytime on the project repository [0]. Until a release come out that
render them useless of course.

Best Regards,
Ben.

[0] https://git.busybox.net/buildroot/tree/boot/syslinux

Beno?t Allard (4):
  memdisk: Force ld output format to 32-bits
  utils: Use the host toolchain to build.
  lzo: Use the host toolchain for prepcore
  efi/wrapper: build it with the host toolchain.

 efi/Makefile     |  2 +-
 lzo/Makefile     |  7 +++++--
 memdisk/Makefile |  2 +-
 utils/Makefile   | 12 ++++++------
 4 files changed, 13 insertions(+), 10 deletions(-)

-- 
2.1.4

On toolchains where the default output is x86_64, we need to be
consistent with the other .o files

Signed-off-by: Beno?t Allard <benoit.allard at greenbone.net>
---
 memdisk/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/memdisk/Makefile b/memdisk/Makefile
index 42e56e0..ccd5738 100644
--- a/memdisk/Makefile
+++ b/memdisk/Makefile
@@ -78,7 +78,7 @@ memdisk16.o: memdisk16.asm
 	$(NASM) -f bin $(NASMOPT) $(NFLAGS) $(NINCLUDE) -o $@ -l $*.lst $<
 
 memdisk_%.o: memdisk_%.bin
-	$(LD) -r -b binary -o $@ $<
+	$(LD) --oformat elf32-i386 -r -b binary -o $@ $<
 
 memdisk16.elf: $(OBJS16)
 	$(LD) -Ttext 0 -o $@ $^
-- 
2.1.4

The utilities are meant to run on the host machine, hence must be built using
the host toolchain.

Signed-off-by: Beno?t Allard <benoit.allard at greenbone.net>
---
 utils/Makefile | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/utils/Makefile b/utils/Makefile
index dfe6259..ac91aaa 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -17,8 +17,8 @@
 VPATH = $(SRC)
 include $(MAKEDIR)/syslinux.mk
 
-CFLAGS   = $(GCCWARN) -Os -fomit-frame-pointer -D_FILE_OFFSET_BITS=64 -I$(SRC)
-LDFLAGS  = -O2
+CFLAGS   = $(CFLAGS_FOR_BUILD) $(GCCWARN) -Os -fomit-frame-pointer
-D_FILE_OFFSET_BITS=64 -I$(SRC)
+LDFLAGS  = $(LDFLAGS_FOR_BUILD) -O2
 
 C_TARGETS	 = isohybrid gethostip memdiskfind
 SCRIPT_TARGETS	 = mkdiskimage
@@ -35,7 +35,7 @@ ISOHDPFX = $(addprefix $(OBJ)/,../mbr/isohdpfx.bin
../mbr/isohdpfx_f.bin \
 all: $(TARGETS)
 
 %.o: %.c
-	$(CC) $(UMAKEDEPS) $(CFLAGS) -c -o $@ $<
+	$(CC_FOR_BUILD) $(UMAKEDEPS) $(CFLAGS) -c -o $@ $<
 
 mkdiskimage: mkdiskimage.in ../mbr/mbr.bin bin2hex.pl
 	$(PERL) $(SRC)/bin2hex.pl < $(OBJ)/../mbr/mbr.bin | cat
$(SRC)/mkdiskimage.in - > $@
@@ -51,13 +51,13 @@ isohdpfx.c: $(ISOHDPFX) isohdpfxarray.pl
 	$(PERL) $(SRC)/isohdpfxarray.pl $(ISOHDPFX) > $@
 
 isohybrid: isohybrid.o isohdpfx.o
-	$(CC) $(LDFLAGS) -o $@ $^ -luuid
+	$(CC_FOR_BUILD) $(LDFLAGS) -o $@ $^ -luuid
 
 gethostip: gethostip.o
-	$(CC) $(LDFLAGS) -o $@ $^
+	$(CC_FOR_BUILD) $(LDFLAGS) -o $@ $^
 
 memdiskfind: memdiskfind.o
-	$(CC) $(LDFLAGS) -o $@ $^
+	$(CC_FOR_BUILD) $(LDFLAGS) -o $@ $^
 
 tidy dist:
 	rm -f *.o .*.d isohdpfx.c
-- 
2.1.4

Signed-off-by: Beno?t Allard <benoit.allard at greenbone.net>
---
 lzo/Makefile | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lzo/Makefile b/lzo/Makefile
index 29f1fa6..c016e5a 100644
--- a/lzo/Makefile
+++ b/lzo/Makefile
@@ -11,10 +11,13 @@
 ## -----------------------------------------------------------------------
 
 VPATH = $(SRC)
-include $(MAKEDIR)/build.mk
+include $(MAKEDIR)/syslinux.mk
 
 INCLUDES += -I$(SRC)/include
 
+%.o: %.c
+	$(CC_FOR_BUILD) $(UMAKEDEPS) $(CFLAGS_FOR_BUILD) $(INCLUDES) -c -o $@ $<
+
 LIBOBJS = $(patsubst %.c,%.o,$(subst $(SRC)/,,$(sort $(wildcard
$(SRC)/src/*.c))))
 LIB     = lzo.a
 BINS    = prepcore
@@ -30,7 +33,7 @@ $(LIB) : $(LIBOBJS)
 	$(RANLIB) $@
 
 prepcore : prepcore.o $(LIB)
-	$(CC) $(LDFLAGS) -o $@ $^ $(LIBS)
+	$(CC_FOR_BUILD) $(LDFLAGS_FOR_BUILD) -o $@ $^ $(LIBS)
 
 tidy dist clean spotless:
 	rm -f $(BINS)
-- 
2.1.4

Signed-off-by: Beno?t Allard <benoit.allard at greenbone.net>
---
 efi/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/efi/Makefile b/efi/Makefile
index d3788d9..a17258a 100644
--- a/efi/Makefile
+++ b/efi/Makefile
@@ -78,7 +78,7 @@ syslinux.so: $(OBJS) $(CORE_OBJS) $(LIB_OBJS)
 #	cp $^ $@
 
 wrapper: wrapper.c
-	$(CC) $^ -o $@
+	$(CC_FOR_BUILD) $^ -o $@
 
 #
 # Build the wrapper app and wrap our .so to produce a .efi
-- 
2.1.4