Rev 285 | Rev 300 | 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> |
285 | decky | 30 | #include <arch/boot/memmapasm.h> |
222 | decky | 31 | |
1 | jermar | 32 | .section K_TEXT_START |
33 | .global kernel_image_start |
||
34 | |||
267 | decky | 35 | KTEXT=8 |
36 | KDATA=16 |
||
37 | |||
1 | jermar | 38 | .code16 |
39 | # |
||
40 | # This is where we require any SPARTAN-kernel-compatible boot loader |
||
41 | # to pass control in real mode. |
||
42 | # |
||
43 | # Protected mode tables are statically initialised during compile |
||
44 | # time. So we can just load the respective table registers and |
||
45 | # switch to protected mode. |
||
46 | # |
||
47 | kernel_image_start: |
||
174 | jermar | 48 | cli |
235 | decky | 49 | xorw %ax, %ax |
50 | movw %ax, %ds |
||
267 | decky | 51 | movw %ax, %ss # initialize stack segment register |
52 | movl $BOOTSTRAP_OFFSET - 0x400, %esp # initialize stack pointer |
||
176 | jermar | 53 | |
54 | call memmap_arch_init |
||
55 | |||
279 | decky | 56 | lgdt real_bootstrap_gdtr # initialize Global Descriptor Table register |
177 | jermar | 57 | |
235 | decky | 58 | movl %cr0, %eax |
59 | orl $0x1, %eax |
||
267 | decky | 60 | movl %eax, %cr0 # switch to protected mode |
235 | decky | 61 | |
267 | decky | 62 | jmpl $KTEXT, $boot_image_start |
235 | decky | 63 | |
112 | jermar | 64 | .code32 |
222 | decky | 65 | .align 4 |
66 | multiboot_header: |
||
67 | .long MULTIBOOT_HEADER_MAGIC |
||
68 | .long MULTIBOOT_HEADER_FLAGS |
||
69 | .long -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEADER_FLAGS) # checksum |
||
235 | decky | 70 | .long multiboot_header + BOOT_OFFSET |
71 | .long unmapped_ktext_start + BOOT_OFFSET |
||
222 | decky | 72 | .long 0 |
73 | .long 0 |
||
235 | decky | 74 | .long multiboot_image_start + BOOT_OFFSET |
222 | decky | 75 | |
235 | decky | 76 | boot_image_start: |
267 | decky | 77 | movw $KDATA, %ax |
235 | decky | 78 | movw %ax, %es |
79 | movw %ax, %gs |
||
80 | movw %ax, %fs |
||
81 | movw %ax, %ds # kernel data + stack |
||
82 | movw %ax, %ss |
||
83 | |||
84 | movb $0xd1, %al # enable A20 using the keyboard controller |
||
85 | outb %al, $0x64 |
||
86 | movb $0xdf, %al |
||
87 | outb %al, $0x60 |
||
88 | |||
267 | decky | 89 | movl $BOOTSTRAP_OFFSET, %esi |
90 | movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %edi |
||
235 | decky | 91 | movl $_hardcoded_kernel_size, %ecx |
92 | cld |
||
93 | rep movsb |
||
94 | |||
285 | decky | 95 | call map_kernel # map kernel and turn paging on |
96 | |||
279 | decky | 97 | call main_bsp # never returns |
98 | |||
99 | cli |
||
100 | hlt |
||
235 | decky | 101 | |
222 | decky | 102 | multiboot_image_start: |
279 | decky | 103 | movl $BOOTSTRAP_OFFSET - 0x400, %esp # initialize stack pointer |
222 | decky | 104 | |
279 | decky | 105 | lgdt protected_bootstrap_gdtr - 0x80000000 # initialize Global Descriptor Table register |
112 | jermar | 106 | |
280 | decky | 107 | movw $KDATA, %cx |
108 | movw %cx, %es |
||
109 | movw %cx, %gs |
||
110 | movw %cx, %fs |
||
111 | movw %cx, %ds # kernel data + stack |
||
112 | movw %cx, %ss |
||
235 | decky | 113 | |
279 | decky | 114 | jmpl $KTEXT, $multiboot_meeting_point + BOOT_OFFSET |
271 | decky | 115 | multiboot_meeting_point: |
116 | |||
285 | decky | 117 | pushl %ebx # save parameters from GRUB |
280 | decky | 118 | pushl %eax |
119 | |||
285 | decky | 120 | movl $BOOTSTRAP_OFFSET + BOOT_OFFSET, %esi |
121 | movl $BOOTSTRAP_OFFSET, %edi |
||
122 | movl $_hardcoded_unmapped_size, %ecx |
||
123 | cld |
||
124 | rep movsb |
||
125 | |||
279 | decky | 126 | call map_kernel # map kernel and turn paging on |
235 | decky | 127 | |
280 | decky | 128 | popl %eax |
129 | popl %ebx |
||
285 | decky | 130 | cmpl $MULTIBOOT_LOADER_MAGIC, %eax # compare GRUB signature |
280 | decky | 131 | je valid_boot |
132 | |||
285 | decky | 133 | xorl %ecx, %ecx # no memory size or map available |
134 | movl %ecx, e801memorysize |
||
135 | movl %ecx, e820counter |
||
136 | |||
280 | decky | 137 | jmp invalid_boot |
285 | decky | 138 | |
280 | decky | 139 | valid_boot: |
140 | |||
285 | decky | 141 | movl (%ebx), %eax # ebx = physical address of struct multiboot_info |
280 | decky | 142 | |
285 | decky | 143 | bt $0, %eax # mbi->flags[0] (mem_lower, mem_upper valid) |
144 | jc mem_valid |
||
145 | |||
146 | xorl %ecx, %ecx |
||
147 | jmp mem_invalid |
||
148 | |||
149 | mem_valid: |
||
150 | movl 4(%ebx), %ecx # mbi->mem_lower |
||
151 | addl 8(%ebx), %ecx # mbi->mem_upper |
||
280 | decky | 152 | |
285 | decky | 153 | mem_invalid: |
280 | decky | 154 | movl %ecx, e801memorysize |
155 | |||
285 | decky | 156 | bt $6, %eax # mbi->flags[6] (mmap_length, mmap_addr valid) |
157 | jc mmap_valid |
||
158 | |||
159 | xorl %edx, %edx |
||
160 | jmp mmap_invalid |
||
161 | |||
162 | mmap_valid: |
||
163 | movl 44(%ebx), %ecx # mbi->mmap_length |
||
164 | movl 48(%ebx), %esi # mbi->mmap_addr |
||
165 | movl $e820table, %edi |
||
166 | xorl %edx, %edx |
||
280 | decky | 167 | |
285 | decky | 168 | mmap_loop: |
169 | cmpl $0, %ecx |
||
170 | jle mmap_end |
||
171 | |||
172 | movl 4(%esi), %eax # mmap->base_addr_low |
||
173 | movl %eax, (%edi) |
||
174 | |||
175 | movl 8(%esi), %eax # mmap->base_addr_high |
||
176 | movl %eax, 4(%edi) |
||
177 | |||
178 | movl 12(%esi), %eax # mmap->length_low |
||
179 | movl %eax, 8(%edi) |
||
180 | |||
181 | movl 16(%esi), %eax # mmap->length_high |
||
182 | movl %eax, 12(%edi) |
||
183 | |||
184 | movl 20(%esi), %eax # mmap->type |
||
185 | movl %eax, 16(%edi) |
||
186 | |||
187 | movl (%esi), %eax # mmap->size |
||
188 | addl $0x4, %eax |
||
189 | addl %eax, %esi |
||
190 | subl %eax, %ecx |
||
191 | addl $MEMMAP_E820_RECORD_SIZE, %edi |
||
192 | incl %edx |
||
193 | jmp mmap_loop |
||
194 | |||
195 | mmap_end: |
||
196 | |||
197 | mmap_invalid: |
||
198 | movl %edx, e820counter |
||
199 | |||
280 | decky | 200 | invalid_boot: |
201 | |||
279 | decky | 202 | call main_bsp - BOOT_OFFSET # never returns |
110 | jermar | 203 | |
204 | cli |
||
205 | hlt |
||
206 | |||
207 | .global map_kernel |
||
208 | map_kernel: |
||
105 | jermar | 209 | # |
210 | # Here we setup mapping for both the unmapped and mapped sections of the kernel. |
||
211 | # For simplicity, we set only one 4M page for 0x00000000 and one for 0x80000000. |
||
212 | # |
||
213 | movl %cr4, %ecx |
||
214 | orl $(1<<4), %ecx |
||
215 | movl %ecx, %cr4 # turn PSE on |
||
1 | jermar | 216 | |
105 | jermar | 217 | movl $((1<<7)|(1<<0)), %eax |
218 | movl %eax, page_directory # mapping 0x00000000 => 0x00000000 |
||
1 | jermar | 219 | |
298 | decky | 220 | movl $(page_directory+2048), %edx |
105 | jermar | 221 | movl %eax, (%edx) # mapping 0x80000000 => 0x00000000 |
222 | |||
223 | leal page_directory, %eax |
||
224 | movl %eax, %cr3 |
||
225 | |||
177 | jermar | 226 | # turn paging on |
105 | jermar | 227 | movl %cr0, %ebx |
228 | orl $(1<<31), %ebx |
||
229 | movl %ebx, %cr0 |
||
110 | jermar | 230 | ret |
105 | jermar | 231 | |
232 | |||
233 | .section K_DATA_START |
||
234 | |||
235 | .align 4096 |
||
236 | page_directory: |
||
237 | .space 4096, 0 |