xref: /freebsd/stand/efi/loader/arch/i386/amd64_tramp.S (revision f8ca5d45c3c1829759ecd87cb95d53e5ab7d0811)
1*f8ca5d45SAhmad Khalifa/*-
2*f8ca5d45SAhmad Khalifa * Copyright (c) 2013 The FreeBSD Foundation
3*f8ca5d45SAhmad Khalifa * Copyright (c) 2023 Ahmad Khalifa <ahmadkhalifa570@gmail.com>
4*f8ca5d45SAhmad Khalifa *
5*f8ca5d45SAhmad Khalifa * This software was developed by Benno Rice under sponsorship from
6*f8ca5d45SAhmad Khalifa * the FreeBSD Foundation.
7*f8ca5d45SAhmad Khalifa * Redistribution and use in source and binary forms, with or without
8*f8ca5d45SAhmad Khalifa * modification, are permitted provided that the following conditions
9*f8ca5d45SAhmad Khalifa * are met:
10*f8ca5d45SAhmad Khalifa * 1. Redistributions of source code must retain the above copyright
11*f8ca5d45SAhmad Khalifa *    notice, this list of conditions and the following disclaimer.
12*f8ca5d45SAhmad Khalifa * 2. Redistributions in binary form must reproduce the above copyright
13*f8ca5d45SAhmad Khalifa *    notice, this list of conditions and the following disclaimer in the
14*f8ca5d45SAhmad Khalifa *    documentation and/or other materials provided with the distribution.
15*f8ca5d45SAhmad Khalifa *
16*f8ca5d45SAhmad Khalifa * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17*f8ca5d45SAhmad Khalifa * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18*f8ca5d45SAhmad Khalifa * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19*f8ca5d45SAhmad Khalifa * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20*f8ca5d45SAhmad Khalifa * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21*f8ca5d45SAhmad Khalifa * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22*f8ca5d45SAhmad Khalifa * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23*f8ca5d45SAhmad Khalifa * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24*f8ca5d45SAhmad Khalifa * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25*f8ca5d45SAhmad Khalifa * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26*f8ca5d45SAhmad Khalifa * SUCH DAMAGE.
27*f8ca5d45SAhmad Khalifa */
28*f8ca5d45SAhmad Khalifa
29*f8ca5d45SAhmad Khalifa#include <machine/asmacros.h>
30*f8ca5d45SAhmad Khalifa
31*f8ca5d45SAhmad Khalifa	.text
32*f8ca5d45SAhmad Khalifa	.globl	amd64_tramp
33*f8ca5d45SAhmad Khalifa
34*f8ca5d45SAhmad Khalifa/*
35*f8ca5d45SAhmad Khalifa * void amd64_tramp(uint32_t stack, void *copy_finish, uint32_t kernend,
36*f8ca5d45SAhmad Khalifa * 		    uint32_t modulep, uint32_t pagetable, uint32_t gdtr, uint64_t entry)
37*f8ca5d45SAhmad Khalifa */
38*f8ca5d45SAhmad Khalifaamd64_tramp:
39*f8ca5d45SAhmad Khalifa	cli	/* Make sure we don't get interrupted. */
40*f8ca5d45SAhmad Khalifa
41*f8ca5d45SAhmad Khalifa	calll *8(%esp)	/* Call copy_finish so we're all ready to go. */
42*f8ca5d45SAhmad Khalifa
43*f8ca5d45SAhmad Khalifa	movl %cr0, %eax	/* Paging may be enabled, disable it. */
44*f8ca5d45SAhmad Khalifa	andl $0x7FFFFFFF, %eax
45*f8ca5d45SAhmad Khalifa	movl %eax, %cr0
46*f8ca5d45SAhmad Khalifa
47*f8ca5d45SAhmad Khalifa	movl %cr4, %eax	/* PAE may be disabled, enable it. */
48*f8ca5d45SAhmad Khalifa	orl $0x20, %eax
49*f8ca5d45SAhmad Khalifa	movl %eax, %cr4
50*f8ca5d45SAhmad Khalifa
51*f8ca5d45SAhmad Khalifa	movl 20(%esp), %eax	/* Swap page tables. */
52*f8ca5d45SAhmad Khalifa	movl %eax, %cr3
53*f8ca5d45SAhmad Khalifa
54*f8ca5d45SAhmad Khalifa	movl $0xC0000080, %ecx	/* Enable long mode. */
55*f8ca5d45SAhmad Khalifa	rdmsr
56*f8ca5d45SAhmad Khalifa	orl $0x100, %eax
57*f8ca5d45SAhmad Khalifa	wrmsr
58*f8ca5d45SAhmad Khalifa
59*f8ca5d45SAhmad Khalifa	movl 12(%esp), %edi	/* Stash the kernel and GDT values for later. */
60*f8ca5d45SAhmad Khalifa	movl 16(%esp), %esi
61*f8ca5d45SAhmad Khalifa	movl 24(%esp), %ebx
62*f8ca5d45SAhmad Khalifa	movl 28(%esp), %edx
63*f8ca5d45SAhmad Khalifa	movl 32(%esp), %ebp
64*f8ca5d45SAhmad Khalifa
65*f8ca5d45SAhmad Khalifa	movl 4(%esp), %esp	/* Switch to our temporary stack. */
66*f8ca5d45SAhmad Khalifa
67*f8ca5d45SAhmad Khalifa	movl %cr0, %eax	/* Enable paging and enter compatibility mode. */
68*f8ca5d45SAhmad Khalifa	orl $0x80000000, %eax
69*f8ca5d45SAhmad Khalifa	movl %eax, %cr0
70*f8ca5d45SAhmad Khalifa
71*f8ca5d45SAhmad Khalifa	lgdtl (%ebx)	/* Load GDT. */
72*f8ca5d45SAhmad Khalifa
73*f8ca5d45SAhmad Khalifa	pushl %edi	/* Push kernend. */
74*f8ca5d45SAhmad Khalifa	pushl %esi	/* Push modulep. */
75*f8ca5d45SAhmad Khalifa	pushl $0x0
76*f8ca5d45SAhmad Khalifa	pushl %ebp	/* Push 64-bit entry address. */
77*f8ca5d45SAhmad Khalifa	pushl %edx
78*f8ca5d45SAhmad Khalifa
79*f8ca5d45SAhmad Khalifa	calll 0f	/* Find the address of ".longmode". */
80*f8ca5d45SAhmad Khalifa0:	popl %eax
81*f8ca5d45SAhmad Khalifa	addl $(.longmode-0b), %eax
82*f8ca5d45SAhmad Khalifa
83*f8ca5d45SAhmad Khalifa	pushl $0x8	/* Push CS. */
84*f8ca5d45SAhmad Khalifa	pushl %eax	/* Push the address. */
85*f8ca5d45SAhmad Khalifa	lretl	/* "Return" to 64-bit code. */
86*f8ca5d45SAhmad Khalifa
87*f8ca5d45SAhmad Khalifa	.code64
88*f8ca5d45SAhmad Khalifa
89*f8ca5d45SAhmad Khalifa.longmode:
90*f8ca5d45SAhmad Khalifa	retq	/* "Return" to kernel entry. */
91*f8ca5d45SAhmad Khalifa
92*f8ca5d45SAhmad Khalifa	.code32
93*f8ca5d45SAhmad Khalifa
94*f8ca5d45SAhmad Khalifa	ALIGN_TEXT
95*f8ca5d45SAhmad Khalifaamd64_tramp_end:
96*f8ca5d45SAhmad Khalifa
97*f8ca5d45SAhmad Khalifa	.data
98*f8ca5d45SAhmad Khalifa	.globl	amd64_tramp_size
99*f8ca5d45SAhmad Khalifaamd64_tramp_size:
100*f8ca5d45SAhmad Khalifa	.long	amd64_tramp_end-amd64_tramp
101