coreboot-kgpe-d16/payloads/libpayload/i386/exec.S

100 lines
2.7 KiB
ArmAsm

/*
* This file is part of the libpayload project.
*
* Copyright (C) 2008 Advanced Micro Devices, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* calling syntax: i386_do_exec(long addr, int argc, char **argv, int *ret) */
/* This implements the payload API detailed here:
* http://www.coreboot.org/Payload_API
*/
.align 4
.text
.global i386_do_exec
.type i386_do_exec,@function
i386_do_exec:
pushl %ebp
movl %esp, %ebp
pushl %eax
/* Put the run address in %eax */
movl 8(%ebp), %eax
/* Save off the rest of the registers */
pushl %esi
pushl %ecx
pushl %ebp
/* Push the argc and argv pointers on to the stack */
movl 12(%ebp), %esi
movl 16(%ebp), %ecx
pushl %esi
pushl %ecx
/* Move a "magic" number on the stack - the other
* payload will use this as a clue that the argc
* and argv are sane
*/
movl $12345678, %ecx
pushl %ecx
/* Jump to the code */
call *%eax
/* %eax has the return value */
/* Skip over the argc/argv stuff still on the stack */
addl $12, %esp
/* Get back %ebp */
popl %ebp
/* Get the pointer to the return value
* and save the return value in it
*/
movl 20(%ebp), %ecx
movl %eax, (%eax)
/* Get the rest of the saved registers */
popl %ecx
popl %esi
popl %eax
/* Restore the stack pointer */
movl %ebp,%esp
popl %ebp
ret