From 01baa05643001638b6d7d6a26123ce04f6c7154c Mon Sep 17 00:00:00 2001 From: Kyle Moffett Date: Wed, 23 Feb 2011 06:40:38 +0000 Subject: powerpc: Minimal private libgcc to build on Debian Standard Debian powerpc and powerpcspe systems only include hard-float libgcc in their native compilers, which causes scary build warnings when building U-Boot. Debian and other PowerPC-supporting distributions used to provide libgcc and other libraries in a "nof" (soft-float) form in the "multilib" packages. As they were completely unused by the distribution and therefore tended to be very buggy it was decided to save some time on the part of the maintainers and build-servers by removing them. Admittedly, right now the linker warnings do not indicate any problems, as the included routines do not use any floating point at all. The concern is that if floating-point code were ever added it might cause hard-float code to be unexpectedly included in U-Boot without generating a hard error. This would cause unexplained crashes or indeterminate results at runtime. The easiest way to resolve this is to borrow the routines that U-Boot needs from the Linux kernel, which has the same issue. Specifically, the routines are: _ashldi3(), _ashrdi3(), and _lshrdi3(). They were borrowed from arch/powerpc/kernel/misc_32.S as of v2.6.38-rc5, commit 85e2efbb1db9a18d218006706d6e4fbeb0216213, and are GPLv2+. The Makefile framework was copied from the U-Boot ARM port. Signed-off-by: Kyle Moffett Cc: Wolfgang Denk Cc: Kim Phillips Cc: Andy Fleming Cc: Kumar Gala Cc: Stefan Roese --- arch/powerpc/lib/Makefile | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/lib/Makefile') diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile index 724d8ee..cdd62a2 100644 --- a/arch/powerpc/lib/Makefile +++ b/arch/powerpc/lib/Makefile @@ -23,6 +23,19 @@ include $(TOPDIR)/config.mk +## Build a couple of necessary functions into a private libgcc +LIBGCC = $(obj)libgcc.o +GLSOBJS += _ashldi3.o +GLSOBJS += _ashrdi3.o +GLSOBJS += _lshrdi3.o +LGOBJS := $(addprefix $(obj),$(GLSOBJS)) \ + $(addprefix $(obj),$(GLCOBJS)) + +## But only build it if the user asked for it +ifdef USE_PRIVATE_LIBGCC +TARGETS += $(LIBGCC) +endif + LIB = $(obj)lib$(ARCH).o SOBJS-y += ppccache.o @@ -53,9 +66,14 @@ endif COBJS += $(sort $(COBJS-y)) -SRCS := $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c) +SRCS := $(GLSOBJS:.o=.S) $(GLCOBJS:.o=.c) \ + $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c) OBJS := $(addprefix $(obj),$(SOBJS-y) $(COBJS-y)) +TARGETS += $(LIB) + +all: $(TARGETS) + $(LIB): $(obj).depend $(OBJS) @if ! $(CROSS_COMPILE)readelf -S $(OBJS) | grep -q '\.fixup.*PROGBITS';\ then \ @@ -65,6 +83,9 @@ $(LIB): $(obj).depend $(OBJS) fi; $(call cmd_link_o_target, $(OBJS)) +$(LIBGCC): $(obj).depend $(LGOBJS) + $(call cmd_link_o_target, $(LGOBJS)) + ######################################################################### # defines $(obj).depend target -- cgit v1.1