xref: /freebsd/stand/efi/loader/arch/amd64/amd64_tramp.S (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1/*-
2 * Copyright (c) 2013 The FreeBSD Foundation
3 *
4 * This software was developed by Benno Rice under sponsorship from
5 * the FreeBSD Foundation.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD$
28 */
29
30#include <machine/asmacros.h>
31
32#define ASM_FILE
33#include "multiboot2.h"
34
35	.text
36	.globl	amd64_tramp
37
38/*
39 * void amd64_tramp(uint64_t stack, void *copy_finish, uint64_t kernend,
40 *		    uint64_t modulep, uint64_t pagetable, uint64_t entry)
41 */
42amd64_tramp:
43	cli			/* Make sure we don't get interrupted. */
44	movq	%rdi,%rsp	/* Switch to our temporary stack. */
45
46	movq	%rdx,%r12	/* Stash the kernel values for later. */
47	movq	%rcx,%r13
48	movq	%r8,%r14
49	movq	%r9,%r15
50
51	callq	*%rsi		/* Call copy_finish so we're all ready to go. */
52
53	pushq	%r12		/* Push kernend. */
54	salq	$32,%r13	/* Shift modulep and push it. */
55	pushq	%r13
56	pushq	%r15		/* Push the entry address. */
57	movq	%r14,%cr3	/* Switch page tables. */
58	ret			/* "Return" to kernel entry. */
59
60	ALIGN_TEXT
61amd64_tramp_end:
62
63/* void multiboot2_exec(uint64_t entry, uint64_t multiboot_info, uint64_t stack) */
64	.globl	multiboot2_exec
65multiboot2_exec:
66	movq	%rdx,%rsp
67	pushq	%rdi
68	movq	%rsi,%rbx
69	movq	$MULTIBOOT2_BOOTLOADER_MAGIC,%rax
70	ret
71
72	.data
73	.globl	amd64_tramp_size
74amd64_tramp_size:
75	.long	amd64_tramp_end-amd64_tramp
76