From 5a45da02cf040ae7eacc9da10f6e8e369a220863 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Sat, 25 May 2013 14:03:25 +0530 Subject: [PATCH] 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 --- arch/arc/Makefile | 24 ++++++++++++++++-------- arch/arc/configs/fpga_defconfig | 2 +- arch/arc/configs/nsimosci_defconfig | 2 +- arch/arc/configs/tb10x_defconfig | 2 +- arch/arc/kernel/vmlinux.lds.S | 24 ++++++++++++++++-------- 5 files changed, 35 insertions(+), 19 deletions(-) diff --git a/arch/arc/Makefile b/arch/arc/Makefile index fbc1b84e31f9..8c0b1aa56f7e 100644 --- a/arch/arc/Makefile +++ b/arch/arc/Makefile @@ -9,7 +9,7 @@ UTS_MACHINE := arc ifeq ($(CROSS_COMPILE),) -CROSS_COMPILE := arc-elf32- +CROSS_COMPILE := arc-linux-uclibc- endif KBUILD_DEFCONFIG := fpga_defconfig @@ -25,7 +25,11 @@ ifdef CONFIG_ARC_CURR_IN_REG LINUXINCLUDE += -include ${src}/arch/arc/include/asm/current.h endif -atleast_gcc44 := $(call cc-ifversion, -gt, 0402, y) +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-$(CONFIG_ARC_HAS_LLSC) += -mlock @@ -33,6 +37,11 @@ cflags-$(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 @@ -46,11 +55,10 @@ cflags-$(disable_small_data) += -mno-sdata -fcall-used-gp cflags-$(CONFIG_CPU_BIG_ENDIAN) += -mbig-endian ldflags-$(CONFIG_CPU_BIG_ENDIAN) += -EB -# STAR 9000518362: +# STAR 9000518362: (fixed with binutils shipping with gcc 4.8) # arc-linux-uclibc-ld (buildroot) or arceb-elf32-ld (EZChip) don't accept -# --build-id w/o "-marclinux". -# Default arc-elf32-ld is OK -ldflags-y += -marclinux +# --build-id w/o "-marclinux". Default arc-elf32-ld is OK +ldflags-$(upto_gcc44) += -marclinux ARC_LIBGCC := -mA7 cflags-$(CONFIG_ARC_HAS_HW_MPY) += -multcost=16 @@ -64,8 +72,8 @@ ifndef CONFIG_ARC_HAS_HW_MPY # With gcc 4.4.7, -mno-mpy is enough to make any other related adjustments, # e.g. increased cost of MPY. With gcc 4.2.1 this had to be explicitly hinted - ARC_LIBGCC := -marc600 - ifneq ($(atleast_gcc44),y) + ifeq ($(upto_gcc42),y) + ARC_LIBGCC := -marc600 cflags-y += -multcost=30 endif endif diff --git a/arch/arc/configs/fpga_defconfig b/arch/arc/configs/fpga_defconfig index 95350be6ef6f..c109af320274 100644 --- a/arch/arc/configs/fpga_defconfig +++ b/arch/arc/configs/fpga_defconfig @@ -1,4 +1,4 @@ -CONFIG_CROSS_COMPILE="arc-elf32-" +CONFIG_CROSS_COMPILE="arc-linux-uclibc-" # CONFIG_LOCALVERSION_AUTO is not set CONFIG_DEFAULT_HOSTNAME="ARCLinux" # CONFIG_SWAP is not set diff --git a/arch/arc/configs/nsimosci_defconfig b/arch/arc/configs/nsimosci_defconfig index 446c96c24eff..451af30914f6 100644 --- a/arch/arc/configs/nsimosci_defconfig +++ b/arch/arc/configs/nsimosci_defconfig @@ -1,4 +1,4 @@ -CONFIG_CROSS_COMPILE="arc-elf32-" +CONFIG_CROSS_COMPILE="arc-linux-uclibc-" # CONFIG_LOCALVERSION_AUTO is not set CONFIG_DEFAULT_HOSTNAME="ARCLinux" # CONFIG_SWAP is not set diff --git a/arch/arc/configs/tb10x_defconfig b/arch/arc/configs/tb10x_defconfig index 4fa5cd9f2202..6be6492442d6 100644 --- a/arch/arc/configs/tb10x_defconfig +++ b/arch/arc/configs/tb10x_defconfig @@ -1,4 +1,4 @@ -CONFIG_CROSS_COMPILE="arc-elf32-" +CONFIG_CROSS_COMPILE="arc-linux-uclibc-" # CONFIG_LOCALVERSION_AUTO is not set CONFIG_DEFAULT_HOSTNAME="tb10x" CONFIG_SYSVIPC=y diff --git a/arch/arc/kernel/vmlinux.lds.S b/arch/arc/kernel/vmlinux.lds.S index d3c92f52d444..2555f5886af6 100644 --- a/arch/arc/kernel/vmlinux.lds.S +++ b/arch/arc/kernel/vmlinux.lds.S @@ -125,6 +125,11 @@ SECTIONS *(.debug_frame) __end_unwind = .; } + /* + * gcc 4.8 generates this for -fasynchonous-unwind-tables, + * while we still use the .debug_frame based unwinder + */ + /DISCARD/ : { *(.eh_frame) } #else /DISCARD/ : { *(.debug_frame) } #endif @@ -142,15 +147,18 @@ SECTIONS *(.arcextmap.*) } +#ifndef CONFIG_DEBUG_INFO /* open-coded because we need .debug_frame seperately for unwinding */ - .debug_aranges 0 : { *(.debug_aranges) } - .debug_pubnames 0 : { *(.debug_pubnames) } - .debug_info 0 : { *(.debug_info) } - .debug_abbrev 0 : { *(.debug_abbrev) } - .debug_line 0 : { *(.debug_line) } - .debug_str 0 : { *(.debug_str) } - .debug_loc 0 : { *(.debug_loc) } - .debug_macinfo 0 : { *(.debug_macinfo) } + /DISCARD/ : { *(.debug_aranges) } + /DISCARD/ : { *(.debug_pubnames) } + /DISCARD/ : { *(.debug_info) } + /DISCARD/ : { *(.debug_abbrev) } + /DISCARD/ : { *(.debug_line) } + /DISCARD/ : { *(.debug_str) } + /DISCARD/ : { *(.debug_loc) } + /DISCARD/ : { *(.debug_macinfo) } + /DISCARD/ : { *(.debug_ranges) } +#endif #ifdef CONFIG_ARC_HAS_DCCM . = CONFIG_ARC_DCCM_BASE; -- 2.45.2