x86: Add implementations of setjmp() and longjmp()

Bring in these functions from Linux v4.4. They will be needed for EFI loader
support.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2016-10-17 20:29:07 -06:00 committed by Bin Meng
parent 2b445e4d31
commit f822403f01
3 changed files with 86 additions and 1 deletions

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@ -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)

61
arch/x86/cpu/setjmp.S Normal file
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@ -0,0 +1,61 @@
/*
* 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
*/
#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 (%edx), %ebx
movl 4(%edx), %esp
movl 8(%edx), %ebp
movl 12(%edx), %esi
movl 16(%edx), %edi
jmp *20(%edx)
.size longjmp, .-longjmp

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@ -0,0 +1,24 @@
/*
* 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
*/
#ifndef __setjmp_h
#define __setjmp_h
struct jmp_buf_data {
unsigned int __ebx;
unsigned int __esp;
unsigned int __ebp;
unsigned int __esi;
unsigned int __edi;
unsigned int __eip;
};
int setjmp(struct jmp_buf_data *jmp_buf);
void longjmp(struct jmp_buf_data *jmp_buf, int val);
#endif