xref: /freebsd/stand/efi/loader/arch/amd64/start.S (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1/*-
2 * Copyright (C) 1999 Hewlett-Packard Co.
3 *     Contributed by David Mosberger <davidm@hpl.hp.com>.
4 * Copyright (C) 2005 Intel Co.
5 *     Contributed by Fenghua Yu <fenghua.yu@intel.com>.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of Hewlett-Packard Co. nor the names of its
17 *    contributors may be used to endorse or promote products derived
18 *    from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
29 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34/*
35 * crt0-efi-x86_64.S - x86_64 EFI startup code.
36 */
37
38	.text
39	.align 4
40
41	.globl _start
42_start:
43	subq $8, %rsp
44	pushq %rcx
45	pushq %rdx
46
470:
48	lea ImageBase(%rip), %rdi
49	lea _DYNAMIC(%rip), %rsi
50
51	popq %rcx
52	popq %rdx
53	pushq %rcx
54	pushq %rdx
55	call self_reloc
56
57	popq %rdi
58	popq %rsi
59
60	call efi_main
61	addq $8, %rsp
62
63.exit:
64	ret
65
66	/*
67	 * hand-craft a dummy .reloc section so EFI knows it's a relocatable
68	 * executable:
69	 */
70
71	.data
72	.section .reloc, "a"
73	.long   0
74	.long   10
75	.word   0
76