xref: /freebsd/stand/efi/loader/arch/amd64/amd64_tramp.S (revision 5e3190f700637fcfc1a52daeaa4a031fdd2557c7)
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
28#include <machine/asmacros.h>
29
30#define ASM_FILE
31#include "multiboot2.h"
32
33	.text
34	.globl	amd64_tramp
35
36/*
37 * void amd64_tramp(uint64_t stack, void *copy_finish, uint64_t kernend,
38 *		    uint64_t modulep, uint64_t pagetable, uint64_t entry)
39 */
40amd64_tramp:
41	cli			/* Make sure we don't get interrupted. */
42	movq	%rdi,%rsp	/* Switch to our temporary stack. */
43
44	movq	%rdx,%r12	/* Stash the kernel values for later. */
45	movq	%rcx,%r13
46	movq	%r8,%r14
47	movq	%r9,%r15
48
49	callq	*%rsi		/* Call copy_finish so we're all ready to go. */
50
51	pushq	%r12		/* Push kernend. */
52	salq	$32,%r13	/* Shift modulep and push it. */
53	pushq	%r13
54	pushq	%r15		/* Push the entry address. */
55	movq	%r14,%cr3	/* Switch page tables. */
56	ret			/* "Return" to kernel entry. */
57
58	ALIGN_TEXT
59amd64_tramp_end:
60
61/* void multiboot2_exec(uint64_t entry, uint64_t multiboot_info, uint64_t stack) */
62	.globl	multiboot2_exec
63multiboot2_exec:
64	movq	%rdx,%rsp
65	pushq	%rdi
66	movq	%rsi,%rbx
67	movq	$MULTIBOOT2_BOOTLOADER_MAGIC,%rax
68	ret
69
70	.data
71	.globl	amd64_tramp_size
72amd64_tramp_size:
73	.long	amd64_tramp_end-amd64_tramp
74