1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
#include <types.h>
#include <multiboot2.h>
#include <graphics.h>
#include <paging.h>
#include <libk/stdio.h>
#include <libk/string.h>
#include <libk/list.h>
#include <heap.h>
#include <kernel_vma.h>
/* https://www.gnu.org/software/grub/manual/multiboot2/html_node/Boot-information-format.html */
mb2_tag_module* ext2_module;
void init_fb(mb2_tag_fb* tag_fb)
{
main_fb.addr = tag_fb->framebuffer_addr;
main_fb.width = tag_fb->framebuffer_width;
main_fb.height = tag_fb->framebuffer_height;
main_fb.pitch = tag_fb->framebuffer_pitch;
main_fb.bpp = tag_fb->framebuffer_bpp;
// identity map framebuffer address
map_addr(main_fb.addr, main_fb.addr, FLAG_PRESENT + FLAG_WRITABLE);
map_addr(main_fb.addr + PAGE_SIZE, main_fb.addr + PAGE_SIZE, FLAG_PRESENT + FLAG_WRITABLE);
}
void init_mmap(mb2_tag_mmap* tag_mmap)
{
list_t* mmap = NULL;
// get data and store it into list
for (size_t i = sizeof(mb2_tag_mmap); i < tag_mmap->size; i += sizeof(mb2_tag_mmap_entry)) {
mb2_tag_mmap_entry* mmap_entry;
mmap_entry = (mb2_tag_mmap_entry*)kalloc(sizeof(mb2_tag_mmap_entry));
memcpy(mmap_entry, (char*)tag_mmap + i, sizeof(mb2_tag_mmap_entry));
add_to_list_head(&mmap, mmap_entry);
}
// print data from list
for (list_t* tmp = mmap; tmp != NULL; tmp = tmp->next) {
mb2_tag_mmap_entry* mmap_entry;
mmap_entry = tmp->data;
// printf("base_addr: 0x%x, length: 0x%x, type: %d\n", mmap_entry->base_addr, mmap_entry->length, mmap_entry->type);
mmap_entry = mmap_entry;
}
// free data
for (list_t* tmp = mmap; tmp != NULL; tmp = tmp->next) {
kfree(tmp->data);
}
// free list
free_list(&mmap);
}
void init_module(mb2_tag_module* tag_module)
{
// name is utf-8 encoded string!
uint32_t name_size = tag_module->size - sizeof(tag_module) + sizeof(char*);
tag_module->name = (char*)kalloc(name_size);
memcpy(tag_module->name, tag_module + tag_module->size - name_size, name_size);
kfree(tag_module->name);
}
void read_mb2(mb2_tag_header* multiboot_bootinfo, uint32_t multiboot_magic)
{
if (multiboot_magic != MB2_MAGIC) {
// not loaded by multiboot2 bootloader
__asm__ volatile ("hlt;");
}
// we will store framebuffer information here
static mb2_tag_fb* tag_fb;
static mb2_tag_mmap* tag_mmap;
// skip first 8 bytes (total_size + reserved)
mb2_tag_header* tag_header = (mb2_tag_header*)((char*)multiboot_bootinfo + 8 + KERNEL_VMA);
while (tag_header->type != MB2_TAG_END) {
// process tag_type
switch(tag_header->type) {
case MB2_TAG_FB:
tag_fb = (mb2_tag_fb*)tag_header;
break;
case MB2_TAG_MMAP:
tag_mmap = (mb2_tag_mmap*)tag_header;
break;
case MB2_TAG_MODULE:
ext2_module = (mb2_tag_module*)tag_header;
break;
default:
break;
}
// next mb2_tag
tag_header += tag_header->size / 8 + ((tag_header->size % 8) > 0);
}
init_fb(tag_fb);
init_mmap(tag_mmap);
init_module(ext2_module);
}
|
