; $Id$

;; @file

; Bootsector that switches the CPU info PAE mode.

;

;

; Copyright (C) 2007-2014 Oracle Corporation

;

; This file is part of VirtualBox Open Source Edition (OSE), as

; available from http://www.virtualbox.org. This file is free software;

; you can redistribute it and/or modify it under the terms of the GNU

; General Public License (GPL) as published by the Free Software

; Foundation, in version 2 as it comes in the "COPYING" file of the

; VirtualBox OSE distribution. VirtualBox OSE is distributed in the

; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.

;

; The contents of this file may alternatively be used under the terms

; of the Common Development and Distribution License Version 1.0

; (CDDL) only, as it comes in the "COPYING.CDDL" file of the

; VirtualBox OSE distribution, in which case the provisions of the

; CDDL are applicable instead of those of the GPL.

;

; You may elect to license modified versions of this file under the

; terms and conditions of either the GPL or the CDDL or both.

;

%include "iprt/asmdefs.mac"

%include "iprt/x86.mac"

;; The boot sector load address.

%define BS_ADDR 0x7c00

%define PDP_ADDR 0x9000

%define PD_ADDR 0xa000

BITS 16

start:

; Start with a jump just to follow the convention.

jmp short the_code

nop

times 3ah db 0

the_code:

cli

xor edx, edx

mov ds, dx ; Use 0 based addresses

;

; Create a paging hierarchy

;

mov cx, 4

xor esi, esi ; physical address

mov ebx, PDP_ADDR

mov edi, PD_ADDR

pdptr_loop:

; The page directory pointer entry.

mov dword [ebx], edi

or word [bx], X86_PDPE_P

mov dword [ebx + 4], edx

; The page directory.

pd_loop:

mov dword [edi], esi

or word [di], X86_PDE4M_P | X86_PDE4M_RW | X86_PDE4M_PS

mov dword [edi + 4], 0

add esi, 0x00200000 ; 2MB

add di, 8

test di, 0fffh

jnz pd_loop

add bx, 8

loop pdptr_loop

;

; Switch to protected mode.

;

lgdt [(gdtr - start) + BS_ADDR]

lidt [(idtr_null - start) + BS_ADDR]

mov eax, PDP_ADDR

mov cr3, eax

mov eax, cr4

or eax, X86_CR4_PAE | X86_CR4_PSE

mov cr4, eax

mov eax, cr0

or eax, X86_CR0_PE | X86_CR0_PG

mov cr0, eax

jmp far 0x0008:((code32_start - start) + BS_ADDR) ; 8=32-bit CS

BITS 32

code32_start:

mov ax, 0x10

mov ds, ax

mov es, ax

mov fs, ax

mov gs, ax

mov ax, 0x18

mov es, ax

mov esp, 0x80000

; eye catchers

mov eax, 0xCafeBabe

mov ebx, eax

mov ecx, eax

mov edx, eax

mov edi, eax

mov esi, eax

mov ebp, eax

;

; Boch shutdown request.

;

mov bl, 64

mov dx, 08900h

retry:

mov ecx, 8

mov esi, (szShutdown - start) + BS_ADDR

rep outsb

dec bl

jnz retry

; Shutdown failed!

hlt_again:

hlt

cli

jmp hlt_again

;

; The GDT.

;

align 8, db 0

gdt:

dw 0, 0, 0, 0 ; null selector

dw 0xffff, 0, 0x9b00, 0x00cf ; 32 bit flat code segment (0x08)

dw 0xffff, 0, 0x9300, 0x00cf ; 32 bit flat data segment (0x10)

dw 0xffff, 0, 0x9300, 0x00cf ; 32 bit flat stack segment (0x18)

gdtr:

dw 8*4-1 ; limit 15:00

dw (gdt - start) + BS_ADDR ; base 15:00

db 0 ; base 23:16

db 0 ; unused

idtr_null:

dw 0 ; limit 15:00

dw (gdt - start) + BS_ADDR ; base 15:00

db 0 ; base 23:16

db 0 ; unused

szShutdown:

db 'Shutdown', 0

;

; Padd the remainder of the sector with zeros and

; end it with the dos signature.

;

padding:

times 510 - (padding - start) db 0

db 055h, 0aah