u-boot/arch/powerpc/lib/Makefile
Kyle Moffett 01baa05643 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 <Kyle.D.Moffett@boeing.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Kim Phillips <kim.phillips@freescale.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Kumar Gala <kumar.gala@freescale.com>
Cc: Stefan Roese <sr@denx.de>
2011-12-07 23:04:32 +01:00

96 lines
2.6 KiB
Makefile

#
# (C) Copyright 2000-2006
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#
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
SOBJS-y += ppcstring.o
SOBJS-y += ticks.o
SOBJS-y += reloc.o
COBJS-$(CONFIG_BAT_RW) += bat_rw.o
COBJS-y += board.o
COBJS-y += bootm.o
COBJS-$(CONFIG_BOOTCOUNT_LIMIT) += bootcount.o
COBJS-y += cache.o
COBJS-y += extable.o
COBJS-y += interrupts.o
COBJS-$(CONFIG_CMD_KGDB) += kgdb.o
COBJS-y += time.o
# Workaround for local bus unaligned access problems
# on MPC512x and MPC5200
ifdef CONFIG_MPC512X
$(obj)ppcstring.o: AFLAGS += -Dmemcpy=__memcpy
COBJS-y += memcpy_mpc5200.o
endif
ifdef CONFIG_MPC5200
$(obj)ppcstring.o: AFLAGS += -Dmemcpy=__memcpy
COBJS-y += memcpy_mpc5200.o
endif
COBJS += $(sort $(COBJS-y))
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 \
echo "ERROR: Your compiler doesn't generate .fixup sections!";\
echo " Upgrade to a recent toolchain."; \
exit 1; \
fi;
$(call cmd_link_o_target, $(OBJS))
$(LIBGCC): $(obj).depend $(LGOBJS)
$(call cmd_link_o_target, $(LGOBJS))
#########################################################################
# defines $(obj).depend target
include $(SRCTREE)/rules.mk
sinclude $(obj).depend
#########################################################################