forked from esp8266/Arduino
-
Notifications
You must be signed in to change notification settings - Fork 0
/
eboot_command.c
65 lines (55 loc) · 1.6 KB
/
eboot_command.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
#include "eboot_command.h"
uint32_t crc_update(uint32_t crc, const uint8_t *data, size_t length)
{
uint32_t i;
bool bit;
uint8_t c;
while (length--) {
c = *data++;
for (i = 0x80; i > 0; i >>= 1) {
bit = crc & 0x80000000;
if (c & i) {
bit = !bit;
}
crc <<= 1;
if (bit) {
crc ^= 0x04c11db7;
}
}
}
return crc;
}
uint32_t eboot_command_calculate_crc32(const struct eboot_command* cmd)
{
return crc_update(0xffffffff, (const uint8_t*) cmd,
offsetof(struct eboot_command, crc32));
}
int eboot_command_read(struct eboot_command* cmd)
{
const uint32_t dw_count = sizeof(struct eboot_command) / sizeof(uint32_t);
uint32_t* dst = (uint32_t *) cmd;
for (uint32_t i = 0; i < dw_count; ++i) {
dst[i] = RTC_MEM[i];
}
uint32_t crc32 = eboot_command_calculate_crc32(cmd);
if (cmd->magic & EBOOT_MAGIC_MASK != EBOOT_MAGIC ||
cmd->crc32 != crc32) {
return 1;
}
return 0;
}
void eboot_command_write(struct eboot_command* cmd)
{
cmd->magic = EBOOT_MAGIC;
cmd->crc32 = eboot_command_calculate_crc32(cmd);
const uint32_t dw_count = sizeof(struct eboot_command) / sizeof(uint32_t);
const uint32_t* src = (const uint32_t *) cmd;
for (uint32_t i = 0; i < dw_count; ++i) {
RTC_MEM[i] = src[i];
}
}
void eboot_command_clear()
{
RTC_MEM[offsetof(struct eboot_command, magic) / sizeof(uint32_t)] = 0;
RTC_MEM[offsetof(struct eboot_command, crc32) / sizeof(uint32_t)] = 0;
}