xref: /freebsd/stand/efi/loader/arch/amd64/amd64_tramp.S (revision 924226fba12cc9a228c73b956e1b7fa24c60b055)
1/*-
2 * Copyright (c) 2013 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Benno Rice under sponsorship from
6 * the FreeBSD Foundation.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <machine/asmacros.h>
32
33#define ASM_FILE
34#include "multiboot2.h"
35
36	.text
37	.globl	amd64_tramp
38
39/*
40 * void amd64_tramp(uint64_t stack, void *copy_finish, uint64_t kernend,
41 *		    uint64_t modulep, uint64_t pagetable, uint64_t entry)
42 */
43amd64_tramp:
44	cli			/* Make sure we don't get interrupted. */
45	movq	%rdi,%rsp	/* Switch to our temporary stack. */
46
47	movq	%rdx,%r12	/* Stash the kernel values for later. */
48	movq	%rcx,%r13
49	movq	%r8,%r14
50	movq	%r9,%r15
51
52	callq	*%rsi		/* Call copy_finish so we're all ready to go. */
53
54	pushq	%r12		/* Push kernend. */
55	salq	$32,%r13	/* Shift modulep and push it. */
56	pushq	%r13
57	pushq	%r15		/* Push the entry address. */
58	movq	%r14,%cr3	/* Switch page tables. */
59	ret			/* "Return" to kernel entry. */
60
61	ALIGN_TEXT
62amd64_tramp_end:
63
64/* void multiboot2_exec(uint64_t entry, uint64_t multiboot_info, uint64_t stack) */
65	.globl	multiboot2_exec
66multiboot2_exec:
67	movq	%rdx,%rsp
68	pushq	%rdi
69	movq	%rsi,%rbx
70	movq	$MULTIBOOT2_BOOTLOADER_MAGIC,%rax
71	ret
72
73	.data
74	.globl	amd64_tramp_size
75amd64_tramp_size:
76	.long	amd64_tramp_end-amd64_tramp
77