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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
#include <comus/memory.h>
#include <comus/asm.h>
#include <comus/mboot.h>
#include <comus/efi.h>
#include <comus/limits.h>
#include <lib.h>
#include "memory.h"
#include "paging.h"
#include "virtalloc.h"
#include "physalloc.h"
// kernel memory context
mem_ctx_t kernel_mem_ctx;
static struct mem_ctx_s _kernel_mem_ctx;
// kernel page tables
extern volatile char kernel_pml4[];
// user space memory contexts
static struct mem_ctx_s user_mem_ctx[N_PROCS];
static struct mem_ctx_s *user_mem_ctx_next = NULL;
void *kmapaddr(void *phys, void *virt, size_t len, unsigned int flags)
{
return mem_mapaddr(kernel_mem_ctx, phys, virt, len, flags);
}
void kunmapaddr(void *virt)
{
mem_unmapaddr(kernel_mem_ctx, virt);
}
void *kalloc_page(void)
{
return mem_alloc_page(kernel_mem_ctx, F_PRESENT | F_WRITEABLE, false);
}
void *kalloc_pages(size_t count)
{
return mem_alloc_pages(kernel_mem_ctx, count, F_PRESENT | F_WRITEABLE,
false);
}
void kfree_pages(void *ptr)
{
mem_free_pages(kernel_mem_ctx, ptr);
}
int kload_page(void *virt)
{
return mem_load_page(kernel_mem_ctx, virt);
}
mem_ctx_t mem_ctx_alloc(void)
{
mem_ctx_t ctx = user_mem_ctx_next;
if (ctx == NULL)
return NULL;
if ((ctx->pml4 = pml4_alloc()) == NULL)
return NULL;
virtaddr_init(&ctx->virtctx);
user_mem_ctx_next = ctx->prev;
if (ctx->prev)
ctx->prev->next = NULL;
ctx->prev = NULL;
return ctx;
}
mem_ctx_t mem_ctx_clone(mem_ctx_t ctx, bool cow)
{
(void)ctx;
(void)cow;
panic("not yet implemented");
}
void mem_ctx_free(mem_ctx_t ctx)
{
pml4_free(ctx->pml4);
virtaddr_cleanup(&ctx->virtctx);
if (user_mem_ctx_next == NULL) {
user_mem_ctx_next = ctx;
} else {
user_mem_ctx_next->next = ctx;
ctx->prev = user_mem_ctx_next;
user_mem_ctx_next = ctx;
}
}
void mem_ctx_switch(mem_ctx_t ctx)
{
__asm__ volatile("mov %0, %%cr3" ::"r"(ctx->pml4) : "memory");
}
void memory_init(void)
{
struct memory_map mmap;
if (mboot_get_mmap(&mmap))
if (efi_get_mmap(&mmap))
panic("failed to load memory map");
kernel_mem_ctx = &_kernel_mem_ctx;
kernel_mem_ctx->pml4 = kernel_pml4;
cli();
paging_init();
virtaddr_init(&kernel_mem_ctx->virtctx);
physalloc_init(&mmap);
sti();
// identiy map EFI functions
for (size_t i = 0; i < mmap.entry_count; i++) {
struct memory_segment *seg = &mmap.entries[i];
if (seg->type != SEG_TYPE_EFI)
continue;
kmapaddr((void *)seg->addr, (void *)seg->addr, seg->len, F_WRITEABLE);
}
// setup user mem ctx linked list
for (size_t i = 0; i < N_PROCS; i++) {
struct mem_ctx_s *ctx = &user_mem_ctx[i];
ctx->next = NULL;
ctx->prev = NULL;
if (user_mem_ctx_next == NULL) {
user_mem_ctx_next = ctx;
continue;
}
user_mem_ctx_next->next = ctx;
ctx->prev = user_mem_ctx_next;
user_mem_ctx_next = ctx;
}
}
|
