grub/loader/i386/bsd_trampoline.S
2009-05-03 10:14:19 +00:00

124 lines
3.4 KiB
ArmAsm

/*
* GRUB -- GRand Unified Bootloader
* Copyright (c) 2003 Peter Wemm <peter@FreeBSD.org>
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
/* Based on the code from FreeBSD originally distributed under the
following terms: */
/*-
* Copyright (c) 2003 Peter Wemm <peter@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#define MSR_EFER 0xc0000080
#define EFER_LME 0x00000100
#define CR4_PAE 0x00000020
#define CR4_PSE 0x00000010
#define CR0_PG 0x80000000
#include <grub/symbol.h>
.p2align 2
.code32
VARIABLE(grub_bsd64_trampoline_start)
/* Discard `grub_unix_real_boot' return address. */
popl %eax
/* entry */
popl %edi
/* entry_hi */
popl %esi
cli
/* Turn on EFER.LME. */
movl $MSR_EFER, %ecx
rdmsr
orl $EFER_LME, %eax
wrmsr
/* Turn on PAE. */
movl %cr4, %eax
orl $(CR4_PAE | CR4_PSE), %eax
movl %eax, %cr4
/* Set %cr3 for PT4. */
popl %eax
movl %eax, %cr3
/* Push a dummy return address. */
pushl %eax
/* Turn on paging (implicitly sets EFER.LMA). */
movl %cr0, %eax
orl $CR0_PG, %eax
movl %eax, %cr0
/* Now we're in compatability mode. set %cs for long mode. */
/* lgdt */
.byte 0x0f
.byte 0x01
.byte 0x15
VARIABLE (grub_bsd64_trampoline_gdt)
.long 0x0
/* ljmp */
.byte 0xea
VARIABLE (grub_bsd64_trampoline_selfjump)
.long 0x0
.word 0x08
.code64
bsd64_longmode:
/* We're still running V=P, jump to entry point. */
movl %esi, %eax
salq $32, %rax
orq %rdi, %rax
pushq %rax
ret
VARIABLE(grub_bsd64_trampoline_end)