[U-Boot] [PATCH v2 1/2] x86: Use default stack boundary alignment
At present U-Boot x86 build is using -mpreferred-stack-boundary=2 which is 4 bytes stack boundary alignment. With 64-bit U-Boot, the minimal required stack boundary alignment is 16 bytes.
If -mpreferred-stack-boundary is not specified, the default is 4 (16 bytes). Switch to use the default one.
Signed-off-by: Bin Meng bmeng.cn@gmail.com ---
Changes in v2: None
arch/x86/config.mk | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 74b87ce..043425e 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -10,8 +10,7 @@ CONFIG_STANDALONE_LOAD_ADDR ?= 0x40000 PLATFORM_CPPFLAGS += -fno-strict-aliasing PLATFORM_CPPFLAGS += -fomit-frame-pointer PF_CPPFLAGS_X86 := $(call cc-option, -fno-toplevel-reorder, \ - $(call cc-option, -fno-unit-at-a-time)) \ - $(call cc-option, -mpreferred-stack-boundary=2) + $(call cc-option, -fno-unit-at-a-time))
PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_X86) PLATFORM_CPPFLAGS += -fno-dwarf2-cfi-asm
64-bit U-Boot image is a combination of 32-bit U-Boot (SPL) plus 64-bit U-Boot (proper). For the U-Boot proper, it has be compiled to 64-bit object codes. Attempting to use a toolchain to compile 64-bit U-Boot for qemu-x86_64, like kernel.org 4.9 i386-linux-gcc, fails with the following errors:
arch/x86/cpu/intel_common/microcode.c:79:2: error: PIC register clobbered by 'ebx' in 'asm'
The issue is because toolchain is preconfigured to generate code for the 32-bit architecture (i386), and currently '-m64' is missing in the makefile fragment. Using kernel.org 4.9 x86_64-linux-gcc works out of the box, since it is preconfigured to generate 64-bit codes.
When compiling U-Boot SPL, '-m32' is passed to the toolchain, no mater 32-bit (i386-linux-) or 64-bit (x86_64-linux) the toolchain is preconfigured to generate.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
---
Changes in v2: - reword the commit message
arch/x86/config.mk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 043425e..8835dcf 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -26,7 +26,7 @@ endif ifeq ($(IS_32BIT),y) PLATFORM_CPPFLAGS += -march=i386 -m32 else -PLATFORM_CPPFLAGS += $(if $(CONFIG_SPL_BUILD),,-fpic) -fno-common +PLATFORM_CPPFLAGS += $(if $(CONFIG_SPL_BUILD),,-fpic) -fno-common -m64 endif
PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden
On 27 July 2017 at 07:12, Bin Meng bmeng.cn@gmail.com wrote:
64-bit U-Boot image is a combination of 32-bit U-Boot (SPL) plus 64-bit U-Boot (proper). For the U-Boot proper, it has be compiled to 64-bit object codes. Attempting to use a toolchain to compile 64-bit U-Boot for qemu-x86_64, like kernel.org 4.9 i386-linux-gcc, fails with the following errors:
arch/x86/cpu/intel_common/microcode.c:79:2: error: PIC register clobbered by 'ebx' in 'asm'
The issue is because toolchain is preconfigured to generate code for the 32-bit architecture (i386), and currently '-m64' is missing in the makefile fragment. Using kernel.org 4.9 x86_64-linux-gcc works out of the box, since it is preconfigured to generate 64-bit codes.
When compiling U-Boot SPL, '-m32' is passed to the toolchain, no mater 32-bit (i386-linux-) or 64-bit (x86_64-linux) the toolchain is preconfigured to generate.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
Changes in v2:
- reword the commit message
arch/x86/config.mk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass sjg@chromium.org
On Tue, Aug 1, 2017 at 5:11 PM, Simon Glass sjg@chromium.org wrote:
On 27 July 2017 at 07:12, Bin Meng bmeng.cn@gmail.com wrote:
64-bit U-Boot image is a combination of 32-bit U-Boot (SPL) plus 64-bit U-Boot (proper). For the U-Boot proper, it has be compiled to 64-bit object codes. Attempting to use a toolchain to compile 64-bit U-Boot for qemu-x86_64, like kernel.org 4.9 i386-linux-gcc, fails with the following errors:
arch/x86/cpu/intel_common/microcode.c:79:2: error: PIC register clobbered by 'ebx' in 'asm'
The issue is because toolchain is preconfigured to generate code for the 32-bit architecture (i386), and currently '-m64' is missing in the makefile fragment. Using kernel.org 4.9 x86_64-linux-gcc works out of the box, since it is preconfigured to generate 64-bit codes.
When compiling U-Boot SPL, '-m32' is passed to the toolchain, no mater 32-bit (i386-linux-) or 64-bit (x86_64-linux) the toolchain is preconfigured to generate.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
Changes in v2:
- reword the commit message
arch/x86/config.mk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Glass sjg@chromium.org
applied to u-boot-x86, thanks!
On 27 July 2017 at 07:12, Bin Meng bmeng.cn@gmail.com wrote:
At present U-Boot x86 build is using -mpreferred-stack-boundary=2 which is 4 bytes stack boundary alignment. With 64-bit U-Boot, the minimal required stack boundary alignment is 16 bytes.
If -mpreferred-stack-boundary is not specified, the default is 4 (16 bytes). Switch to use the default one.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
Changes in v2: None
arch/x86/config.mk | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
Reviewed-by: Simon Glass sjg@chromium.org
On Tue, Aug 1, 2017 at 5:11 PM, Simon Glass sjg@chromium.org wrote:
On 27 July 2017 at 07:12, Bin Meng bmeng.cn@gmail.com wrote:
At present U-Boot x86 build is using -mpreferred-stack-boundary=2 which is 4 bytes stack boundary alignment. With 64-bit U-Boot, the minimal required stack boundary alignment is 16 bytes.
If -mpreferred-stack-boundary is not specified, the default is 4 (16 bytes). Switch to use the default one.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
Changes in v2: None
arch/x86/config.mk | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
Reviewed-by: Simon Glass sjg@chromium.org
applied to u-boot-x86, thanks!
participants (2)
-
Bin Meng -
Simon Glass