xref: /openbmc/u-boot/arch/x86/lib/crt0_x86_64_efi.S (revision 3ebd892f)
1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * crt0-efi-x86_64.S - x86_64 EFI startup code.
4 * Copyright (C) 1999 Hewlett-Packard Co.
5 * Contributed by David Mosberger <davidm@hpl.hp.com>.
6 * Copyright (C) 2005 Intel Corporation
7 * Contributed by Fenghua Yu <fenghua.yu@intel.com>.
8 *
9 * All rights reserved.
10 */
11	.text
12	.align 4
13
14	.globl _start
15_start:
16	subq $8, %rsp
17
18	pushq %rcx
19	pushq %rdx
20
21	mov %rcx, %r8
22	mov %rdx, %r9
23
24	lea image_base(%rip), %rcx
25	lea _DYNAMIC(%rip), %rdx
26
27	call _relocate
28
29	popq %rdx
30	popq %rcx
31
32	testq %rax, %rax
33	jnz .exit
34
35	call efi_main
36.exit:
37	addq $8, %rsp
38
39	ret
40
41	/*
42	 * hand-craft a dummy .reloc section so EFI knows it's a relocatable
43	 * executable:
44	 */
45	.data
46dummy:	.long	0
47
48#define IMAGE_REL_ABSOLUTE	0
49	.section .reloc, "a"
50label1:
51	.long	dummy-label1				/* Page RVA */
52	.long	10					/* Block Size (2*4+2) */
53	.word	(IMAGE_REL_ABSOLUTE << 12) +  0		/* reloc for dummy */
54