ezri/qmk_firmware
1
0
Fork 0
Code Issues Pull Requests Actions 2 Packages Projects Releases Wiki Activity

fl16: Validate serial number with CRC32B checksum

Browse Source 
Signed-off-by: Daniel Schaefer <dhs@frame.work>
This commit is contained in:
Daniel Schaefer 2023-08-07 15:36:54 +08:00
parent 8093dfeb18
commit ca08e9373a
1 changed files with 38 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
keyboards/framework/dyn_serial.c
View File

@ -18,26 +18,53 @@ USB_Descriptor_String_t PROGMEM SerialNumberString = {
char ascii_serialnum[SERIALNUM_LEN+1];
void *dyn_serial_number_string(void) {
// TODO: Fix this
// Need to remove the logic here because it overlaps with VIA settings
return &SerialNumberString;
struct __attribute__((__packed__)) serialnum_raw {
uint8_t sn_rev;
uint8_t serialnum[SERIALNUM_LEN];
uint8_t crc32[4];
};
// Exit early, if it was previously read and converted
if (ascii_serialnum[0] != '\0' || ascii_serialnum[0] == 0xFF) {
uint32_t crc32b(uint8_t *message, size_t msg_len) {
uint8_t byte;
uint32_t crc;
uint32_t mask;
crc = 0xFFFFFFFF;
for (size_t i = 0; i < msg_len; i++) {
byte = message[i];
crc = crc ^ byte;
for (int j = 0; j < 8; j++) {
mask = -(crc & 1);
crc = (crc >> 1) ^ (0xEDB88320 & mask);
}
}
return ~crc;
}
void *dyn_serial_number_string(void) {
// Read ASCII serial number from memory-mapped flash
void *serialnum_ptr = (void*) (FLASH_OFFSET + LAST_4K_BLOCK);
struct serialnum_raw *serialnum_raw = serialnum_ptr;
// Only rev 1 supported
if (serialnum_raw->sn_rev != 1) {
return &SerialNumberString;
}
// Read ASCII serial number from memory-mapped flash
char *serialnum_ptr = (char*) (FLASH_OFFSET + LAST_4K_BLOCK);
memcpy(ascii_serialnum, serialnum_ptr, SERIALNUM_LEN);
uint32_t crc32 = crc32b(serialnum_ptr, SERIALNUM_LEN+1);
// Make sure it's little-endian
uint32_t crc32_read = (serialnum_raw->crc32[3] << 24) +
(serialnum_raw->crc32[2] << 16) +
(serialnum_raw->crc32[1] << 8) +
serialnum_raw->crc32[0];
// Just keep fallback serialnumber if the flash is erased
if (ascii_serialnum[0] == 0xFF) {
// CRC invalid, fall back to defult serial number
if (crc32_read != crc32) {
return &SerialNumberString;
}
// Convert to UCS-2, which is equivalent to UTF-16, if the input is ASCII
memcpy(ascii_serialnum, serialnum_raw->serialnum, SERIALNUM_LEN);
for (int i = 0; i < SERIALNUM_LEN; i++) {
if (ascii_serialnum[i] > 128) {
dprintf("Serial number character %d is not valid ASCII.", ascii_serialnum[i]);