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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
/*
* Copyright (c) 2025 Ian Marco Moffett and the Osmora Team.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPKERNE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LKERNS 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
* PKERNSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/param.h>
#include <kern/panic.h>
#include <os/trace.h>
#include <vm/phys.h>
#include <vm/vm.h>
#include <lib/limine.h>
#include <lib/string.h>
#include <lib/stdbool.h>
#define dtrace(fmt, ...) trace("phys: " fmt, ##__VA_ARGS__)
#define MEM_GIB 0x40000000
#define MEM_MIB 0x100000
/* Aliases for portability */
#define MEM_USABLE (LIMINE_MEMMAP_USABLE)
#define MEM_RESERVED (LIMINE_MEMMAP_RESERVED)
#define MEM_ACPI_RECLAIMABLE (LIMINE_MEMMAP_ACPI_RECLAIMABLE)
#define MEM_ACPI_NVS (LIMINE_MEMMAP_ACPI_NVS)
#define MEM_BAD (LIMINE_MEMMAP_BAD_MEMORY)
#define MEM_BOOTLOADER (LIMINE_MEMMAP_BOOTLOADER_RECLAIMABLE)
#define MEM_KERNEL (LIMINE_MEMMAP_KERNEL_AND_MODULES)
#define MEM_FRAMEBUFFER (LIMINE_MEMMAP_FRAMEBUFFER)
#define MEM_ENTRY(INDEX) (memmap_resp->entries[(INDEX)])
#define MEM_ENTRY_COUNT (memmap_resp->entry_count)
typedef struct limine_memmap_entry mementry_t;
/* Bitmap */
static uint8_t *bitmap = NULL;
/* Memory statistics */
static size_t total_mem = 0;
static size_t free_mem = 0;
static size_t reserved_mem = 0;
static size_t bitmap_size = 0;
static uintptr_t highest_usable = 0;
/*
* Request a memor map from the bootloader
*/
static struct limine_memmap_response *memmap_resp;
static volatile struct limine_memmap_request memmap_req = {
.id = LIMINE_MEMMAP_REQUEST,
.revision = 0
};
/*
* Print memory size related stats
*/
static void
vm_printstat(const char *name, size_t size)
{
if (size >= MEM_GIB) {
dtrace("%s %d GiB\n", name, size / MEM_GIB);
} else {
dtrace("%s %d MiB\n", name, size / MEM_MIB);
}
}
/*
* Set a range in a bitmap as allocated or free
*/
static void
bitmap_set_range(uintptr_t start, uintptr_t end, bool alloc)
{
/* Clamp the range */
start = ALIGN_DOWN(start, PAGESIZE);
end = ALIGN_UP(end, PAGESIZE);
for (uintptr_t p = start; p < end; p += PAGESIZE) {
if (alloc) {
setbit(bitmap, p / PAGESIZE);
} else {
clrbit(bitmap, p / PAGESIZE);
}
}
}
/*
* Populate bitmap entries based on what is free and
* what is not
*/
static void
vm_fill_bitmap(void)
{
uintptr_t start, end;
size_t entries_set = 0;
mementry_t *entry;
for (size_t i = 0; i < MEM_ENTRY_COUNT; ++i) {
entry = MEM_ENTRY(i);
/* Drop unusable entries */
if (entry->type != MEM_USABLE) {
continue;
}
start = entry->base;
end = entry->base + entry->length;
bitmap_set_range(start, end, false);
++entries_set;
}
dtrace("populated %d entries\n", entries_set);
}
/*
* Find a physical memory hole big enough to fit the
* bitmap
*/
static void
vm_alloc_bitmap(void)
{
mementry_t *entry;
for (size_t i = 0; i < MEM_ENTRY_COUNT; ++i) {
entry = MEM_ENTRY(i);
/* Drop unusable entries */
if (entry->type != MEM_USABLE) {
continue;
}
/* Does the bitmap fit here? */
if (entry->length >= bitmap_size) {
bitmap = PHYS_TO_VIRT(entry->base);
entry->length -= bitmap_size;
entry->base += bitmap_size;
break;
}
}
if (__unlikely(bitmap == NULL)) {
panic("vm: unable to allocate framedb\n");
}
/* Populate the bitmap */
memset(bitmap, 0xFF, bitmap_size);
vm_fill_bitmap();
}
/*
* Probe for usable memory
*/
static void
vm_probe(void)
{
mementry_t *entry;
for (size_t i = 0; i < MEM_ENTRY_COUNT; ++i) {
entry = MEM_ENTRY(i);
if (entry->type != MEM_USABLE) {
total_mem += entry->length;
reserved_mem += entry->length;
continue;
}
total_mem += entry->length;
free_mem += entry->length;
if ((entry->base + entry->length) > highest_usable) {
highest_usable = entry->base + entry->length;
}
}
/* Print some stats */
vm_printstat("memory installed", total_mem);
vm_printstat("memory usable", free_mem);
vm_printstat("memory reserved", reserved_mem);
dtrace("usable top @ %p\n", highest_usable);
/* Compute the bitmap size */
bitmap_size = highest_usable / PAGESIZE;
bitmap_size /= 8;
dtrace("framedb len : %d bytes\n", bitmap_size);
vm_alloc_bitmap();
}
void
vm_phys_init(void)
{
memmap_resp = memmap_req.response;
if (__unlikely(memmap_resp == NULL)) {
panic("vm: unable to get memory map\n");
}
dtrace("checking memory resources...\n");
vm_probe();
}
|
