From f49513f666ed25d24bdf3a02a1fdb5d18ae081c0 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Sat, 16 Jul 2016 00:16:11 +0200 Subject: BaseTools/tools_def: switch GCC/X64 to the PIE small model The ordinary small code model for x86_64 cannot be used in UEFI, since it assumes the executable is loaded in the first 2 GB of memory. Therefore, we use the large model instead, which can execute anywhere, but uses absolute 64-bit wide quantities for all symbol references, which is costly in terms of code size. So switch to the PIE small code model, this uses 32-bit relative references where possible, but does not make any assumptions about the load address (i.e., all absolute symbol references are 64-bits wide). Note that, due to the 'protected' visibility pragma introduced in an earlier patch, there is no need for the EDK2 build system to deal with GOT related ELF relocation types. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel Reviewed-by: Jordan Justen Tested-by: Laszlo Ersek Tested-By: Liming Gao Reviewed-by: Liming Gao --- BaseTools/Conf/tools_def.template | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template index 32fc1270bd..847b9f729f 100644 --- a/BaseTools/Conf/tools_def.template +++ b/BaseTools/Conf/tools_def.template @@ -4355,7 +4355,7 @@ DEFINE GCC_AARCH64_RC_FLAGS = -I binary -O elf64-littleaarch64 -B aarch64 DEFINE GCC44_ALL_CC_FLAGS = -g -fshort-wchar -fno-strict-aliasing -Wall -Werror -Wno-array-bounds -ffunction-sections -fdata-sections -c -include AutoGen.h -fno-common -DSTRING_ARRAY_NAME=$(BASE_NAME)Strings DEFINE GCC44_IA32_CC_FLAGS = DEF(GCC44_ALL_CC_FLAGS) -m32 -march=i586 -malign-double -fno-stack-protector -D EFI32 -fno-asynchronous-unwind-tables -DEFINE GCC44_X64_CC_FLAGS = DEF(GCC44_ALL_CC_FLAGS) -m64 -fno-stack-protector "-DEFIAPI=__attribute__((ms_abi))" -Os -maccumulate-outgoing-args -mno-red-zone -Wno-address -mcmodel=large -fno-asynchronous-unwind-tables +DEFINE GCC44_X64_CC_FLAGS = DEF(GCC44_ALL_CC_FLAGS) -m64 -fno-stack-protector "-DEFIAPI=__attribute__((ms_abi))" -Os -maccumulate-outgoing-args -mno-red-zone -Wno-address -mcmodel=small -fpie -fno-asynchronous-unwind-tables DEFINE GCC44_IA32_X64_DLINK_COMMON = -nostdlib -n -q --gc-sections -z common-page-size=0x20 DEFINE GCC44_IA32_X64_ASLDLINK_FLAGS = DEF(GCC44_IA32_X64_DLINK_COMMON) --entry ReferenceAcpiTable -u ReferenceAcpiTable DEFINE GCC44_IA32_X64_DLINK_FLAGS = DEF(GCC44_IA32_X64_DLINK_COMMON) --entry $(IMAGE_ENTRY_POINT) -u $(IMAGE_ENTRY_POINT) -Map $(DEST_DIR_DEBUG)/$(BASE_NAME).map -- cgit v1.2.3