Subversion Repositories HelenOS

Rev

Rev 216 | Rev 232 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 jermar 1
#
2
# Copyright (C) 2001-2004 Jakub Jermar
3
# All rights reserved.
4
#
5
# Redistribution and use in source and binary forms, with or without
6
# modification, are permitted provided that the following conditions
7
# are met:
8
#
9
# - Redistributions of source code must retain the above copyright
10
#   notice, this list of conditions and the following disclaimer.
11
# - Redistributions in binary form must reproduce the above copyright
12
#   notice, this list of conditions and the following disclaimer in the
13
#   documentation and/or other materials provided with the distribution.
14
# - The name of the author may not be used to endorse or promote products
15
#   derived from this software without specific prior written permission.
16
#
17
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
#
28
 
222 decky 29
#include <arch/boot/boot.h>
30
 
1 jermar 31
.section K_TEXT_START
32
.global kernel_image_start
33
 
34
.code16
35
#
36
# This is where we require any SPARTAN-kernel-compatible boot loader
37
# to pass control in real mode.
38
#
39
# Protected mode tables are statically initialised during compile
40
# time. So we can just load the respective table registers and
41
# switch to protected mode.
42
#
43
kernel_image_start:
174 jermar 44
	cli
1 jermar 45
	xorw %ax,%ax
46
	movw %ax,%ds
176 jermar 47
	movw %ax,%ss			# initialize stack segment register
48
	movl $0x7c00,%esp		# initialize stack pointer
49
 
50
	call memmap_arch_init
51
 
177 jermar 52
	lgdt gdtr			# initialize Global Descriptor Table register
53
	lidt idtr			# initialize Interrupt Descriptor Table register
54
 
1 jermar 55
	movl %cr0,%eax
56
	orl $0x1,%eax
177 jermar 57
	movl %eax,%cr0			# switch to protected mode
112 jermar 58
	jmpl $8,$meeting_point
222 decky 59
 
112 jermar 60
.code32
222 decky 61
.align 4
62
multiboot_header:
63
	.long MULTIBOOT_HEADER_MAGIC
64
	.long MULTIBOOT_HEADER_FLAGS
65
	.long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS)	# checksum
66
	.long multiboot_header
67
	.long unmapped_ktext_start
68
	.long 0
69
	.long 0
70
	.long multiboot_image_start
71
 
72
multiboot_image_start:
73
	movl $0x7c00, %esp		# initialize stack pointer
74
 
75
	lgdt gdtr
76
	lidt idtr
112 jermar 77
 
222 decky 78
meeting_point:
1 jermar 79
	movw $16,%ax
80
	movw %ax,%es
81
	movw %ax,%gs
82
	movw %ax,%fs
83
	movw %ax,%ds			# kernel data + stack
125 jermar 84
	movw %ax,%ss
1 jermar 85
 
177 jermar 86
	call map_kernel			# map kernel and turn paging on
1 jermar 87
 
110 jermar 88
	call main_bsp			# never returns
89
 
90
	cli
91
	hlt
92
 
93
.global map_kernel
94
map_kernel:
105 jermar 95
	#
96
	# Here we setup mapping for both the unmapped and mapped sections of the kernel.
97
	# For simplicity, we set only one 4M page for 0x00000000 and one for 0x80000000.
98
	#
99
	movl %cr4, %ecx
100
	orl $(1<<4), %ecx
101
	movl %ecx, %cr4				# turn PSE on
1 jermar 102
 
105 jermar 103
	movl $((1<<7)|(1<<0)), %eax
104
	movl %eax, page_directory		# mapping 0x00000000 => 0x00000000
1 jermar 105
 
105 jermar 106
	movl $(page_directory+(4096/2)), %edx
107
	movl %eax, (%edx)			# mapping 0x80000000 => 0x00000000
108
 
109
	leal page_directory, %eax
110
	movl %eax, %cr3
111
 
177 jermar 112
	# turn paging on
105 jermar 113
	movl %cr0, %ebx
114
	orl $(1<<31), %ebx
115
	movl %ebx, %cr0
110 jermar 116
	ret
105 jermar 117
 
118
 
119
.section K_DATA_START
120
 
121
.align 4096
122
page_directory:
123
	.space 4096, 0