| /*- |
| * 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. |
| * |
| * $FreeBSD$ |
| */ |
| |
| /* |
| * Quick and dirty trampoline to get into 64 bit (long) mode and running |
| * with paging enabled so that we enter the kernel at its linked address. |
| */ |
| #define MSR_EFER 0xc0000080 |
| #define EFER_LME 0x00000100 |
| #define CR4_PAE 0x00000020 |
| #define CR4_PSE 0x00000010 |
| #define CR0_PG 0x80000000 |
| |
| /* GRRR. Deal with BTX that links us for a non-zero location */ |
| #define VPBASE 0xa000 |
| #define VTOP(x) ((x) + VPBASE) |
| |
| .data |
| |
| .p2align 12,0x40 |
| |
| .globl PT4 |
| PT4: |
| .space 0x1000 |
| .globl PT3 |
| PT3: |
| .space 0x1000 |
| .globl PT2 |
| PT2: |
| .space 0x1000 |
| |
| gdtdesc: |
| .word gdtend - gdt |
| .long VTOP(gdt) # low |
| .long 0 # high |
| |
| gdt: |
| .long 0 # null descriptor |
| .long 0 |
| .long 0x00000000 # %cs |
| .long 0x00209800 |
| .long 0x00000000 # %ds |
| .long 0x00008000 |
| gdtend: |
| |
| .text |
| .code32 |
| |
| .globl amd64_tramp |
| amd64_tramp: |
| /* Be sure that interrupts are disabled */ |
| cli |
| |
| /* Turn on EFER.LME */ |
| movl $MSR_EFER, %ecx |
| rdmsr |
| orl $EFER_LME, %eax |
| wrmsr |
| |
| /* Turn on PAE */ |
| movl %cr4, %eax |
| orl $CR4_PAE, %eax |
| movl %eax, %cr4 |
| |
| /* Set %cr3 for PT4 */ |
| movl $VTOP(PT4), %eax |
| movl %eax, %cr3 |
| |
| /* 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 */ |
| movl $VTOP(gdtdesc), %eax |
| movl VTOP(entry_hi), %esi |
| movl VTOP(entry_lo), %edi |
| lgdt (%eax) |
| ljmp $0x8, $VTOP(longmode) |
| |
| .code64 |
| longmode: |
| /* We're still running V=P, jump to entry point */ |
| movl %esi, %eax |
| salq $32, %rax |
| orq %rdi, %rax |
| pushq %rax |
| ret |