Change-Id: Ia9170bd3d04e76dbf9321ca7ea4be23b5e468d21 Signed-off-by: Stefan Reinauer <reinauer@google.com> Reviewed-on: http://review.coreboot.org/2033 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
		
			
				
	
	
		
			105 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			105 lines
		
	
	
		
			2.8 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.
 | 
						|
 */
 | 
						|
 | 
						|
	.code32
 | 
						|
	.global _entry, _leave
 | 
						|
	.text
 | 
						|
	.align 4
 | 
						|
 | 
						|
/*
 | 
						|
 * Our entry point - assume that the CPU is in 32 bit protected mode and
 | 
						|
 * all segments are in a flat model. That's our operating mode, so we won't
 | 
						|
 * change anything.
 | 
						|
 */
 | 
						|
_entry:
 | 
						|
	jmp _init
 | 
						|
 | 
						|
	.align 4
 | 
						|
 | 
						|
#define MB_MAGIC 0x1BADB002
 | 
						|
#define MB_FLAGS 0x00010003
 | 
						|
 | 
						|
mb_header:
 | 
						|
	.long MB_MAGIC
 | 
						|
	.long MB_FLAGS
 | 
						|
	.long -(MB_MAGIC + MB_FLAGS)
 | 
						|
	.long mb_header
 | 
						|
	.long _start
 | 
						|
	.long _edata
 | 
						|
	.long _end
 | 
						|
	.long _init
 | 
						|
 | 
						|
/*
 | 
						|
 * This function saves off the previous stack and switches us to our
 | 
						|
 * own execution environment.
 | 
						|
 */
 | 
						|
_init:
 | 
						|
	/* No interrupts, please. */
 | 
						|
	cli
 | 
						|
 | 
						|
	/* There is a bunch of stuff missing here to take arguments on the stack
 | 
						|
	 * See http://www.coreboot.org/Payload_API and exec.S.
 | 
						|
	 */
 | 
						|
	/* Store current stack pointer. */
 | 
						|
	movl %esp, %esi
 | 
						|
 | 
						|
	/* Store EAX and EBX */
 | 
						|
	movl %eax,loader_eax
 | 
						|
	movl %ebx,loader_ebx
 | 
						|
 | 
						|
	/* Clear the bss */
 | 
						|
	cld
 | 
						|
	movl $.bss, %edi
 | 
						|
	movl $_end, %ecx
 | 
						|
	subl %edi, %ecx
 | 
						|
	xor %ax, %ax
 | 
						|
	rep stosb
 | 
						|
 | 
						|
	/* Setup new stack. */
 | 
						|
	movl $_stack, %ebx
 | 
						|
 | 
						|
	movl %ebx, %esp
 | 
						|
 | 
						|
	/* Save old stack pointer. */
 | 
						|
	pushl %esi
 | 
						|
 | 
						|
	/* Let's rock. */
 | 
						|
	call start_main
 | 
						|
 | 
						|
	/* %eax has the return value - pass it on unmolested */
 | 
						|
_leave:
 | 
						|
	/* Get old stack pointer. */
 | 
						|
	popl %ebx
 | 
						|
 | 
						|
	/* Restore old stack. */
 | 
						|
	movl %ebx, %esp
 | 
						|
 | 
						|
	/* Return to the original context. */
 | 
						|
	ret
 |