-
Notifications
You must be signed in to change notification settings - Fork 21
/
linuxbios.c
165 lines (152 loc) · 3.79 KB
/
linuxbios.c
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
#include "linuxbios_tables.h"
#include "test.h"
static unsigned long ip_compute_csum(void *addr, unsigned long length)
{
uint16_t *ptr;
unsigned long sum;
unsigned long len;
unsigned long laddr;
/* compute an ip style checksum */
laddr = (unsigned long )addr;
sum = 0;
if (laddr & 1) {
uint16_t buffer;
unsigned char *ptr;
/* copy the first byte into a 2 byte buffer.
* This way automatically handles the endian question
* of which byte (low or high) the last byte goes in.
*/
buffer = 0;
ptr = addr;
memmove(&buffer, ptr, 1);
sum += buffer;
if (sum > 0xFFFF)
sum -= 0xFFFF;
length -= 1;
addr = ptr +1;
}
len = length >> 1;
ptr = addr;
while (len--) {
sum += *(ptr++);
if (sum > 0xFFFF)
sum -= 0xFFFF;
}
addr = ptr;
if (length & 1) {
uint16_t buffer;
unsigned char *ptr;
/* copy the last byte into a 2 byte buffer.
* This way automatically handles the endian question
* of which byte (low or high) the last byte goes in.
*/
buffer = 0;
ptr = addr;
memmove(&buffer, ptr, 1);
sum += buffer;
if (sum > 0xFFFF)
sum -= 0xFFFF;
}
return (~sum) & 0xFFFF;
}
#define for_each_lbrec(head, rec) \
for(rec = (struct lb_record *)(((char *)head) + sizeof(*head)); \
(((char *)rec) < (((char *)head) + sizeof(*head) + head->table_bytes)) && \
(rec->size >= 1) && \
((((char *)rec) + rec->size) <= (((char *)head) + sizeof(*head) + head->table_bytes)); \
rec = (struct lb_record *)(((char *)rec) + rec->size))
static int count_lb_records(struct lb_header *head)
{
struct lb_record *rec;
int count;
count = 0;
for_each_lbrec(head, rec) {
count++;
}
return count;
}
static struct lb_header * __find_lb_table(unsigned long start, unsigned long end)
{
unsigned long addr;
/* For now be stupid.... */
for(addr = start; addr < end; addr += 16) {
struct lb_header *head = (struct lb_header *)addr;
struct lb_record *recs = (struct lb_record *)(addr + sizeof(*head));
if (memcmp(head->signature, "LBIO", 4) != 0)
continue;
if (head->header_bytes != sizeof(*head))
continue;
if (ip_compute_csum((unsigned char *)head, sizeof(*head)) != 0)
continue;
if (ip_compute_csum((unsigned char *)recs, head->table_bytes)
!= head->table_checksum)
continue;
if (count_lb_records(head) != head->table_entries)
continue;
return head;
};
return 0;
}
static struct lb_header * find_lb_table(void)
{
struct lb_header *head;
head = 0;
if (!head) {
/* First try at address 0 */
head = __find_lb_table(0x00000, 0x1000);
}
if (!head) {
/* Then try at address 0xf0000 */
head = __find_lb_table(0xf0000, 0x100000);
}
return head;
}
int query_linuxbios(void)
{
struct lb_header *head;
struct lb_record *rec;
struct lb_memory *mem;
struct lb_forward *forward;
int i, entries;
head = find_lb_table();
if (!head) {
return 0;
}
/* coreboot also can forward the table to the high tables area. */
rec = (struct lb_record *)(((char *)head) + sizeof(*head));
if (rec->tag == LB_TAG_FORWARD) {
forward = (struct lb_forward *)rec;
head = (struct lb_header *)(unsigned long)(forward->forward);
if (!head) { return 0; }
}
mem = 0;
for_each_lbrec(head, rec) {
if (rec->tag == LB_TAG_MEMORY) {
mem = (struct lb_memory *)rec;
break;
}
}
if (!mem) {
return 1;
}
entries = (mem->size - sizeof(*mem))/sizeof(mem->map[0]);
if (entries == 0)
return 1;
mem_info.e820_nr = 0;
for(i = 0; i < entries; i++) {
unsigned long long start;
unsigned long long size;
unsigned long type;
if (i >= E820MAX) {
break;
}
start = mem->map[i].start;
size = mem->map[i].size;
type = (mem->map[i].type == LB_MEM_RAM)?E820_RAM: E820_RESERVED;
mem_info.e820[mem_info.e820_nr].addr = start;
mem_info.e820[mem_info.e820_nr].size = size;
mem_info.e820[mem_info.e820_nr].type = type;
mem_info.e820_nr++;
}
return 1;
}