u-boot/arch/powerpc/config.mk
Wolfgang Denk c08e5cf7c7 POWERPC: enable --gc-sections and -ffunction-sections -fdata-sections
The switch from archive libraries to partial linking has introduced a
number of problems, that are non-trivial to solve.  For example, it is
no longer possible to include individual object files in the linker
script as we did before for example in the case of boards with
embedded environment to fill up the gap caused by the need to align
the environment on flash erase block boundaries.

The best (but unfortunately not easiest) approach to address this
problem is to enable -ffunction-sections (and -fdata-sections) so
we can again (and even in much finer granularity) place certain code
where we want it.  When doing this step, it seems only consequent to
also add --gc-sections which has the added benefit of reducing the
memory footprint of the U-Boot image (both in flash and in RAM).

Unfortunately, this requires changes to a lot of linker scripts.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Kim Phillips <kim.phillips@freescale.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Stefan Roese <sr@denx.de>
2010-11-27 23:35:08 +01:00

56 lines
1.8 KiB
Makefile

#
# (C) Copyright 2000-2010
# 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
#
CROSS_COMPILE ?= ppc_8xx-
STANDALONE_LOAD_ADDR = 0x40000
PLATFORM_RELFLAGS += -mrelocatable -ffunction-sections -fdata-sections
PLATFORM_CPPFLAGS += -DCONFIG_PPC -D__powerpc__
PLATFORM_LDFLAGS += -n --gc-sections
ifdef CONFIG_SYS_LDSCRIPT
# need to strip off double quotes
LDSCRIPT := $(subst ",,$(CONFIG_SYS_LDSCRIPT))
else ifdef CONFIG_NAND_SPL
LDSCRIPT := $(SRCTREE)/$(CONFIG_BOARDDIR)/u-boot-nand.lds
else
ifneq ($(wildcard $(SRCTREE)/arch/powerpc/cpu/$(CPU)/u-boot.lds),)
LDSCRIPT := $(SRCTREE)/arch/powerpc/cpu/$(CPU)/u-boot.lds
endif
endif
#
# When cross-compiling on NetBSD, we have to define __PPC__ or else we
# will pick up a va_list declaration that is incompatible with the
# actual argument lists emitted by the compiler.
#
# [Tested on NetBSD/i386 1.5 + cross-powerpc-netbsd-1.3]
ifeq ($(CROSS_COMPILE),powerpc-netbsd-)
PLATFORM_CPPFLAGS+= -D__PPC__
endif
ifeq ($(CROSS_COMPILE),powerpc-openbsd-)
PLATFORM_CPPFLAGS+= -D__PPC__
endif