On 26.09.16 09:00, Bin Meng wrote:
Hi Simon,
On Mon, Sep 26, 2016 at 5:27 AM, Simon Glass sjg@chromium.org wrote:
Bring in these functions from Linux v4.4. They will be needed for EFI loader support.
Signed-off-by: Simon Glass sjg@chromium.org
Changes in v2:
- Drop irrelevant comment
- Add a comment about .size
- Drop unnecessary .text directive
- Make longjmp() always cause setjmp() to return 1
arch/x86/cpu/Makefile | 2 +- arch/x86/cpu/setjmp.S | 66 +++++++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/setjmp.h | 24 ++++++++++++++++ 3 files changed, 91 insertions(+), 1 deletion(-) create mode 100644 arch/x86/cpu/setjmp.S create mode 100644 arch/x86/include/asm/setjmp.h
diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile index 2667e0b..f5b8c9e 100644 --- a/arch/x86/cpu/Makefile +++ b/arch/x86/cpu/Makefile @@ -10,7 +10,7 @@
extra-y = start.o obj-$(CONFIG_X86_RESET_VECTOR) += resetvec.o start16.o -obj-y += interrupts.o cpu.o cpu_x86.o call64.o +obj-y += interrupts.o cpu.o cpu_x86.o call64.o setjmp.o
AFLAGS_REMOVE_call32.o := -mregparm=3 \ $(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32) diff --git a/arch/x86/cpu/setjmp.S b/arch/x86/cpu/setjmp.S new file mode 100644 index 0000000..7443274 --- /dev/null +++ b/arch/x86/cpu/setjmp.S @@ -0,0 +1,66 @@ +/*
- Written by H. Peter Anvin hpa@zytor.com
- Brought in from Linux v4.4 and modified for U-Boot
- From Linux arch/um/sys-i386/setjmp.S
- SPDX-License-Identifier: GPL-2.0
- */
+#include <asm/global_data.h> +#include <asm/msr-index.h> +#include <asm/processor-flags.h>
I believe the above 3 includes are not needed.
+#define _REGPARM
+/*
- The jmp_buf is assumed to contain the following, in order:
%ebx
%esp
%ebp
%esi
%edi
<return address>- */
.text.align 4.globl setjmp.type setjmp, @function+setjmp: +#ifdef _REGPARM
movl %eax, %edx+#else
movl 4(%esp), %edx+#endif
popl %ecx /* Return address, and adjust the stack */xorl %eax, %eax /* Return value */movl %ebx, (%edx)movl %esp, 4(%edx) /* Post-return %esp! */pushl %ecx /* Make the call/return stack happy */movl %ebp, 8(%edx)movl %esi, 12(%edx)movl %edi, 16(%edx)movl %ecx, 20(%edx) /* Return address */ret/* Provide function size if needed */.size setjmp, .-setjmp.align 4.globl longjmp.type longjmp, @function+longjmp: +#ifdef _REGPARM
xchgl %eax, %edx+#else
movl 4(%esp), %edx /* jmp_ptr address */+#endif
movl 1, %eaxThis should be $1.
But I still think the setjmp/longjump codes in efi_loader is wrong. We should have longjump() to pass the return value to setjmp().
Why? Where's the difference?
Alex