u-boot/arch/x86/cpu/i386/setjmp.S
Heinrich Schuchardt fc872ee84c x86: fix longjmp() implementation
If longjmp(jmp_buf env, int val) is called with val = 0, the setjmp()
macro must return 1.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2022-10-29 07:36:33 -06:00

65 lines
1.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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
*/
#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 */
movl 8(%esp), %eax /* Return value */
#endif
movl (%edx), %ebx
movl 4(%edx), %esp
movl 8(%edx), %ebp
movl 12(%edx), %esi
movl 16(%edx), %edi
test %eax, %eax
jnz nz
inc %eax
nz:
jmp *20(%edx)
.size longjmp, .-longjmp