linux/arch/arc/Makefile
Vineet Gupta 5a45da02cf ARC: Adjustments for gcc 4.8
* DWARF unwinder related
  + Force DWARF2 compliant .debug_frame (gcc 4.8 defaults to DWARF4
    which kernel unwinder can't grok).
  + Discard the additional .eh_frame generated
  + Discard the dwarf4 debug info generated by -gdwarf-2 for normal
    no debug case

* 4.8 already uses arc600 multilibs for -mno-mpy

* switch to using uclibc compiler (to get -mmedium-calls and -mno-sdata)
  and also since buildroot can only use 1 toolchain

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2013-06-27 14:35:32 +05:30

140 lines
4.3 KiB
Makefile

#
# 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.
#
UTS_MACHINE := arc
ifeq ($(CROSS_COMPILE),)
CROSS_COMPILE := arc-linux-uclibc-
endif
KBUILD_DEFCONFIG := fpga_defconfig
cflags-y += -mA7 -fno-common -pipe -fno-builtin -D__linux__
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_gcc42 := $(call cc-ifversion, -le, 0402, y)
upto_gcc44 := $(call cc-ifversion, -le, 0404, y)
atleast_gcc44 := $(call cc-ifversion, -ge, 0404, y)
atleast_gcc48 := $(call cc-ifversion, -ge, 0408, y)
cflags-$(atleast_gcc44) += -fsection-anchors
cflags-$(CONFIG_ARC_HAS_LLSC) += -mlock
cflags-$(CONFIG_ARC_HAS_SWAPE) += -mswape
cflags-$(CONFIG_ARC_HAS_RTSC) += -mrtsc
cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables
# By default gcc 4.8 generates dwarf4 which kernel unwinder can't grok
ifeq ($(atleast_gcc48),y)
cflags-$(CONFIG_ARC_DW2_UNWIND) += -gdwarf-2
endif
ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
# Generic build system uses -O2, we want -O3
cflags-y += -O3
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
ARC_LIBGCC := -mA7
cflags-$(CONFIG_ARC_HAS_HW_MPY) += -multcost=16
ifndef CONFIG_ARC_HAS_HW_MPY
cflags-y += -mno-mpy
# newlib for ARC700 assumes MPY to be always present, which is generally true
# However, if someone really doesn't want MPY, we need to use the 600 ver
# which coupled with -mno-mpy will use mpy emulation
# With gcc 4.4.7, -mno-mpy is enough to make any other related adjustments,
# e.g. increased cost of MPY. With gcc 4.2.1 this had to be explicitly hinted
ifeq ($(upto_gcc42),y)
ARC_LIBGCC := -marc600
cflags-y += -multcost=30
endif
endif
LIBGCC := $(shell $(CC) $(ARC_LIBGCC) $(cflags-y) --print-libgcc-file-name)
# Modules with short calls might break for calls into builtin-kernel
KBUILD_CFLAGS_MODULE += -mlong-calls
# Finally dump eveything into kernel build system
KBUILD_CFLAGS += $(cflags-y)
KBUILD_AFLAGS += $(KBUILD_CFLAGS)
LDFLAGS += $(ldflags-y)
head-y := arch/arc/kernel/head.o
# See arch/arc/Kbuild for content of core part of the kernel
core-y += arch/arc/
# w/o this dtb won't embed into kernel binary
core-y += arch/arc/boot/dts/
core-$(CONFIG_ARC_PLAT_FPGA_LEGACY) += arch/arc/plat-arcfpga/
core-$(CONFIG_ARC_PLAT_TB10X) += arch/arc/plat-tb10x/
drivers-$(CONFIG_OPROFILE) += arch/arc/oprofile/
libs-y += arch/arc/lib/ $(LIBGCC)
boot := arch/arc/boot
#default target for make without any arguements.
KBUILD_IMAGE := bootpImage
all: $(KBUILD_IMAGE)
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 dtbs
archclean:
$(Q)$(MAKE) $(clean)=$(boot)
# Hacks to enable final link due to absence of link-time branch relexation
# and gcc choosing optimal(shorter) branches at -O3
#
# vineetg Feb 2010: -mlong-calls switched off for overall kernel build
# However lib/decompress_inflate.o (.init.text) calls
# zlib_inflate_workspacesize (.text) causing relocation errors.
# Thus forcing all exten calls in this file to be long calls
export CFLAGS_decompress_inflate.o = -mmedium-calls
export CFLAGS_initramfs.o = -mmedium-calls
ifdef CONFIG_SMP
export CFLAGS_core.o = -mmedium-calls
endif