[U-Boot-Users] [PATCH 1/2] [BUILD] Generate include/autoconf.mk from board config files

Wolfgang Denk wd at denx.de
Tue Dec 18 09:53:26 CET 2007

In message <20071121055107.19848.96219.stgit at trillian.cg.shawcable.net> you wrote:
> Use cpp and sed to postprocess config.h and import the defined values
> into include/autoconf.mk.  autoconf.mk is then included by config.mk to
> give 'make' access to the board configuration.
> Doing this enables conditional compilation at the Makefile level instead
> of by wrapping every .c file with #ifdef/#endif wrappers.

Unfortunately this breaks building with older (GCC-3.x) compilers.

> +$(OBJTREE)/include/autoconf.mk: $(obj)include/config.h
> +	@echo Generating include/autoconf.mk
> +	@# Generate the dependancies
> +	@$(CC) -M $(HOST_CFLAGS) $(CPPFLAGS) -MQ $@ include/common.h > $@.dep
Does not work with GCC-3.x:

+ ppc_8xx-gcc -M -g -Os -fPIC -ffixed-r14 -meabi -fno-strict-aliasing -D__KERNEL__ -DTEXT_BASE=0x40000000 -I/home/wd/git/u-boot/work/include -fno-builtin -ffreestanding -nostdinc -isystem /opt/eldk-3.1.1/usr/bin/../lib/gcc-lib/ppc-linux/3.3.3/include -pipe -DCONFIG_PPC -D__powerpc__ -DCONFIG_8xx -ffixed-r2 -ffixed-r29 -mstring -mcpu=860 -msoft-float -MQ /home/wd/git/u-boot/work/include/autoconf.mk include/common.h
ppc_8xx-gcc: compilation of header file requested
+ echo RC=1

[Tested with ELDK 3.1.1]

The effect is even more nasty, as  make  will  not  stop  afgter  the
error;  if  you  ignore  the  "compilation  of header file requested"
message, but continues  until  it  runs  into  problems  later  (when

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
C makes it easy for you to shoot yourself in the foot. C++ makes that
harder, but when you do, it blows away your whole leg.
                                                 -- Bjarne Stroustrup

More information about the U-Boot mailing list