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#

# Copyright (C) 2001-2004 Ondrej Palkovsky

# All rights reserved.

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions

# are met:

#

# - Redistributions of source code must retain the above copyright

#   notice, this list of conditions and the following disclaimer.

# - 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.

# - The name of the author may not be used to endorse or promote products

#   derived from this software without specific prior written permission.

#

# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.

#

#define __ASM__

#include <arch/mm/page.h>	

#include <arch/mm/ptl.h>

#include <arch/pm.h>

#include <arch/cpu.h>

#define START_STACK     0x7c00	

#define START_STACK_64  0xffffffff80007c00

#

# This is where we require any SPARTAN-kernel-compatible boot loader

# to pass control in real mode.

#

# Protected mode tables are statically initialised during compile

# time. So we can just load the respective table registers and

# switch to protected mode.

#

.section K_TEXT_START

.code16

.global kernel_image_start

kernel_image_start:

	cli

	xorw %ax,%ax

	movw %ax,%ds

	movw %ax,%ss            # initialize stack segment register

	movl $(START_STACK),%esp	# initialize stack pointer

	call memmap_arch_init

	movl $0x80000000, %eax  

	cpuid

	cmp $0x80000000, %eax 	# any function > 80000000h?

	jbe no_long_mode

	movl $0x80000001, %eax	# Extended function code 80000001

	cpuid

	bt $29, %edx 		# Test if long mode is supported.

	jnc no_long_mode

	# Load gdtr, idtr

	lgdt gdtr_inst

	# Load idtr, but it contains mess - we should not get interrupt

	# anyway

	lidt idtr_inst

	movl %cr0,%eax

	orl $0x1,%eax

	movl %eax,%cr0			# switch to protected mode

	jmpl $gdtselector(KTEXT32_DES), $now_in_prot

no_long_mode:

1:

	jmp 1b

# Protected 16-bit. We want to reuse the code-seg descriptor,

# the Default operand size must not be 1 when entering long mode	

now_in_prot:  

	# Set up stack & data descriptors

	movw $gdtselector(KDATA_DES), %ax

	movw %ax, %ds

	movw %ax, %fs

	movw %ax, %gs

	movw %ax, %ss

	# Enable 64-bit page transaltion entries - CR4.PAE = 1.

	# Paging is not enabled until after long mode is enabled

	movl %cr4, %eax

	btsl $5, %eax

	movl %eax, %cr4

	# Set up paging tables

	leal ptl_0, %eax

	movl %eax, %cr3

	# Enable long mode

	movl $EFER_MSR_NUM, %ecx   # EFER MSR number

	rdmsr                   # Read EFER

	btsl $AMD_LME_FLAG, %eax            # Set LME=1

	wrmsr                   # Write EFER

	# Enable paging to activate long mode (set CR0.PG=1)

	movl %cr0, %eax

	btsl $31, %eax

	movl %eax, %cr0

	# At this point we are in compatibility mode

	jmpl $gdtselector(KTEXT_DES), $start64

.code64

start64:

	movq $(START_STACK_64), %rsp

	call main_bsp   # never returns

1:

	jmp 1b

.section K_DATA_START

.align 4096

# Identical mapping of first 16MB and the same of -2GB -> 0	

.global ptl_2

ptl_2:	

	.quad 0x0 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0x200000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0x400000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0x600000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0x800000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0xa00000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0xc00000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

	.quad 0xe00000 | (PTL_WRITABLE | PTL_PRESENT | PTL_2MB_PAGE)

.align 4096

.global ptl_1

ptl_1:

	.quad ptl_2 + (PTL_WRITABLE | PTL_PRESENT)

	.fill 509,8,0

	.quad ptl_2 + (PTL_WRITABLE | PTL_PRESENT)

	.fill 2,8,0

.align 4096

.global ptl_0

ptl_0:

	.quad ptl_1 + (PTL_WRITABLE | PTL_PRESENT)

	.fill 510,8,0

	.quad ptl_1 + (PTL_WRITABLE | PTL_PRESENT)

.global gdtr_inst				

gdtr_inst:

	.word gdtselector(GDT_ITEMS)

	.long KA2PA(gdt)

.global idtr_inst

idtr_inst:

	.word idtselector(IDT_ITEMS)

	.long KA2PA(idt)