linux_old1/arch/arc/Makefile

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#
# Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
ifeq ($(CROSS_COMPILE),)
ifndef CONFIG_CPU_BIG_ENDIAN
CROSS_COMPILE := arc-linux-
else
CROSS_COMPILE := arceb-linux-
endif
endif
KBUILD_DEFCONFIG := nsim_700_defconfig
ARC: Explicitly add -mmedium-calls to CFLAGS GCC built for arc*-*-linux has "-mmedium-calls" implicitly enabled by default thus we don't see any problems during Linux kernel compilation. ----------------------------->8------------------------ arc-linux-gcc -mcpu=arc700 -Q --help=target | grep calls -mlong-calls [disabled] -mmedium-calls [enabled] ----------------------------->8------------------------ But if we try to use so-called Elf32 toolchain with GCC configured for arc*-*-elf* then we'd see the following failure: ----------------------------->8------------------------ init/do_mounts.o: In function 'init_rootfs': do_mounts.c:(.init.text+0x108): relocation truncated to fit: R_ARC_S21W_PCREL against symbol 'unregister_filesystem' defined in .text section in fs/filesystems.o arc-elf32-ld: final link failed: Symbol needs debug section which does not exist make: *** [vmlinux] Error 1 ----------------------------->8------------------------ That happens because neither "-mmedium-calls" nor "-mlong-calls" are enabled in Elf32 GCC: ----------------------------->8------------------------ arc-elf32-gcc -mcpu=arc700 -Q --help=target | grep calls -mlong-calls [disabled] -mmedium-calls [disabled] ----------------------------->8------------------------ Now to make it possible to use Elf32 toolchain for building Linux kernel we're explicitly add "-mmedium-calls" to CFLAGS. And since we add "-mmedium-calls" to the global CFLAGS there's no point in having per-file copies thus removing them. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2018-06-01 19:34:33 +08:00
cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
cflags-$(CONFIG_ISA_ARCOMPACT) += -mA7
cflags-$(CONFIG_ISA_ARCV2) += -mcpu=archs
is_700 = $(shell $(CC) -dM -E - < /dev/null | grep -q "ARC700" && echo 1 || echo 0)
ifdef CONFIG_ISA_ARCOMPACT
ifeq ($(is_700), 0)
$(error Toolchain not configured for ARCompact builds)
endif
endif
ifdef CONFIG_ISA_ARCV2
ifeq ($(is_700), 1)
$(error Toolchain not configured for ARCv2 builds)
endif
endif
ifdef CONFIG_ARC_CURR_IN_REG
# For a global register defintion, make sure it gets passed to every file
# We had a customer reported bug where some code built in kernel was NOT using
# any kernel headers, and missing the r25 global register
# Can't do unconditionally because of recursive include issues
# due to <linux/thread_info.h>
LINUXINCLUDE += -include ${src}/arch/arc/include/asm/current.h
endif
upto_gcc44 := $(call cc-ifversion, -le, 0404, y)
atleast_gcc44 := $(call cc-ifversion, -ge, 0404, y)
cflags-$(atleast_gcc44) += -fsection-anchors
cflags-$(CONFIG_ARC_HAS_LLSC) += -mlock
cflags-$(CONFIG_ARC_HAS_SWAPE) += -mswape
ifdef CONFIG_ISA_ARCV2
ifndef CONFIG_ARC_HAS_LL64
cflags-y += -mno-ll64
endif
ifndef CONFIG_ARC_HAS_DIV_REM
cflags-y += -mno-div-rem
endif
endif
cfi := $(call as-instr,.cfi_startproc\n.cfi_endproc,-DARC_DW2_UNWIND_AS_CFI)
cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables $(cfi)
ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
# Generic build system uses -O2, we want -O3
# Note: No need to add to cflags-y as that happens anyways
Kbuild: enable -Wmaybe-uninitialized warning for "make W=1" Traditionally, we have always had warnings about uninitialized variables enabled, as this is part of -Wall, and generally a good idea [1], but it also always produced false positives, mainly because this is a variation of the halting problem and provably impossible to get right in all cases [2]. Various people have identified cases that are particularly bad for false positives, and in commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os"), I turned off the warning for any build that was done with CC_OPTIMIZE_FOR_SIZE. This drastically reduced the number of false positive warnings in the default build but unfortunately had the side effect of turning the warning off completely in 'allmodconfig' builds, which in turn led to a lot of warnings (both actual bugs, and remaining false positives) to go in unnoticed. With commit 877417e6ffb9 ("Kbuild: change CC_OPTIMIZE_FOR_SIZE definition") enabled the warning again for allmodconfig builds in v4.7 and in v4.8-rc1, I had finally managed to address all warnings I get in an ARM allmodconfig build and most other maybe-uninitialized warnings for ARM randconfig builds. However, commit 6e8d666e9253 ("Disable "maybe-uninitialized" warning globally") was merged at the same time and disabled it completely for all configurations, because of false-positive warnings on x86 that I had not addressed until then. This caused a lot of actual bugs to get merged into mainline, and I sent several dozen patches for these during the v4.9 development cycle. Most of these are actual bugs, some are for correct code that is safe because it is only called under external constraints that make it impossible to run into the case that gcc sees, and in a few cases gcc is just stupid and finds something that can obviously never happen. I have now done a few thousand randconfig builds on x86 and collected all patches that I needed to address every single warning I got (I can provide the combined patch for the other warnings if anyone is interested), so I hope we can get the warning back and let people catch the actual bugs earlier. This reverts the change to disable the warning completely and for now brings it back at the "make W=1" level, so we can get it merged into mainline without introducing false positives. A follow-up patch enables it on all levels unless some configuration option turns it off because of false-positives. Link: https://rusty.ozlabs.org/?p=232 [1] Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11 00:44:44 +08:00
#
# Disable the false maybe-uninitialized warings gcc spits out at -O3
ARCH_CFLAGS += -O3 $(call cc-disable-warning,maybe-uninitialized,)
endif
# small data is default for elf32 tool-chain. If not usable, disable it
# This also allows repurposing GP as scratch reg to gcc reg allocator
disable_small_data := y
cflags-$(disable_small_data) += -mno-sdata -fcall-used-gp
cflags-$(CONFIG_CPU_BIG_ENDIAN) += -mbig-endian
ldflags-$(CONFIG_CPU_BIG_ENDIAN) += -EB
# STAR 9000518362: (fixed with binutils shipping with gcc 4.8)
# arc-linux-uclibc-ld (buildroot) or arceb-elf32-ld (EZChip) don't accept
# --build-id w/o "-marclinux". Default arc-elf32-ld is OK
ldflags-$(upto_gcc44) += -marclinux
LIBGCC := $(shell $(CC) $(cflags-y) --print-libgcc-file-name)
# Modules with short calls might break for calls into builtin-kernel
KBUILD_CFLAGS_MODULE += -mlong-calls -mno-millicode
# Finally dump eveything into kernel build system
KBUILD_CFLAGS += $(cflags-y)
KBUILD_AFLAGS += $(KBUILD_CFLAGS)
LDFLAGS += $(ldflags-y)
head-y := arch/arc/kernel/head.o
# See arch/arc/Kbuild for content of core part of the kernel
core-y += arch/arc/
# w/o this dtb won't embed into kernel binary
core-y += arch/arc/boot/dts/
core-y += arch/arc/plat-sim/
core-$(CONFIG_ARC_PLAT_TB10X) += arch/arc/plat-tb10x/
core-$(CONFIG_ARC_PLAT_AXS10X) += arch/arc/plat-axs10x/
core-$(CONFIG_ARC_PLAT_EZNPS) += arch/arc/plat-eznps/
core-$(CONFIG_ARC_SOC_HSDK) += arch/arc/plat-hsdk/
ifdef CONFIG_ARC_PLAT_EZNPS
KBUILD_CPPFLAGS += -I$(srctree)/arch/arc/plat-eznps/include
endif
drivers-$(CONFIG_OPROFILE) += arch/arc/oprofile/
libs-y += arch/arc/lib/ $(LIBGCC)
boot := arch/arc/boot
#default target for make without any arguments.
KBUILD_IMAGE := $(boot)/bootpImage
all: bootpImage
bootpImage: vmlinux
boot_targets += uImage uImage.bin uImage.gz
$(boot_targets): vmlinux
$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
%.dtb %.dtb.S %.dtb.o: scripts
$(Q)$(MAKE) $(build)=$(boot)/dts $(boot)/dts/$@
dtbs: scripts
$(Q)$(MAKE) $(build)=$(boot)/dts
archclean:
$(Q)$(MAKE) $(clean)=$(boot)