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![Wolfgang Denk](/assets/img/avatar_default.png)
For some time there have been repeated reports about build problems with some ARM (cross) tool chains. Especially issues about (in)compatibility with the tool chain provided runtime support library libgcc.a caused to add and support a private implementation of such runtime support code in U-Boot. A closer look at the code indicated that some of these issues are actually home-made. This patch attempts to clean up some of the most obvious problems and make building of U-Boot with different tool chains easier: - Even though all ARM systems basicy used the same compiler options to select a specific ABI from the tool chain, the code for this was distributed over all cpu/*/config.mk files. We move this one level up into lib_arm/config.mk instead. - So far, we only checked if "-mapcs-32" was supported by the tool chain; if yes, this was used, if not, "-mabi=apcs-gnu" was selected, no matter if the tool chain actually understood this option. There was no support for EABI conformant tool chains. This patch implements the following logic: 1) If the tool chain supports "-mabi=aapcs-linux -mno-thumb-interwork" we use these options (EABI conformant tool chain). 2) Otherwise, we check first if "-mapcs-32" is supported, and then check for "-mabi=apcs-gnu" If one test succeeds, we use the first found option. 3) In case 2), we also test if "-mno-thumb-interwork", and use this if the test succeeds. [For "-mabi=aapcs-linux" we set "-mno-thumb-interwork" mandatorily.] This way we use a similar logic for the compile options as the Linux kernel does. - Some EABI conformant tool chains cause external references to utility functions like raise(); such functions are provided in the new file lib_arm/eabi_compat.c Note that lib_arm/config.mk gets parsed several times, so we must make sure to add eabi_compat.o only once to the linker list. Signed-off-by: Wolfgang Denk <wd@denx.de> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Dirk Behme <dirk.behme@googlemail.com> Cc: Magnus Lilja <lilja.magnus@gmail.com> Cc: Tom Rix <Tom.Rix@windriver.com> Cc: Prafulla Wadaskar <prafulla@marvell.com> Acked-by: Sergey Kubushyn <ksi@koi8.net> Tested-by: Magnus Lilja <lilja.magnus@gmail.com> Tested-by: Andrzej Wolski <awolski@poczta.fm> Tested-by: Gaye Abdoulaye Walsimou <walsimou@walsimou.com> Tested-by: Tom Rix <Tom.Rix@windriver.com> Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
57 lines
1.9 KiB
Makefile
57 lines
1.9 KiB
Makefile
#
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# (C) Copyright 2000-2002
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# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
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#
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# See file CREDITS for list of people who contributed to this
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# project.
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#
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# This program is free software; you can redistribute it and/or
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# modify it under the terms of the GNU General Public License as
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# published by the Free Software Foundation; either version 2 of
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# the License, or (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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# MA 02111-1307 USA
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#
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CROSS_COMPILE ?= arm-linux-
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PLATFORM_CPPFLAGS += -DCONFIG_ARM -D__ARM__
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# Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:
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PLATFORM_CPPFLAGS += $(call cc-option,-marm,)
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# Try if EABI is supported, else fall back to old API,
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# i. e. for example:
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# - with ELDK 4.2 (EABI supported), use:
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# -mabi=aapcs-linux -mno-thumb-interwork
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# - with ELDK 4.1 (gcc 4.x, no EABI), use:
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# -mabi=apcs-gnu -mno-thumb-interwork
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# - with ELDK 3.1 (gcc 3.x), use:
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# -mapcs-32 -mno-thumb-interwork
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PLATFORM_CPPFLAGS += $(call cc-option,\
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-mabi=aapcs-linux -mno-thumb-interwork,\
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$(call cc-option,\
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-mapcs-32,\
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$(call cc-option,\
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-mabi=apcs-gnu,\
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)\
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) $(call cc-option,-mno-thumb-interwork,)\
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)
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# For EABI, make sure to provide raise()
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ifneq (,$(findstring -mabi=aapcs-linux,$(PLATFORM_CPPFLAGS)))
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# This file is parsed several times; make sure to add only once.
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ifeq (,$(findstring lib_arm/eabi_compat.o,$(PLATFORM_LIBS)))
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PLATFORM_LIBS += $(OBJTREE)/lib_arm/eabi_compat.o
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endif
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endif
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LDSCRIPT := $(SRCTREE)/cpu/$(CPU)/u-boot.lds
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