unleashed-firmware/lib/nfc/helpers/nfc_util.c
gornekich d92b0a82cc
NFC refactoring (#3050)
"A long time ago in a galaxy far, far away...." we started NFC subsystem refactoring.

Starring:

- @gornekich - NFC refactoring project lead, architect, senior developer
- @gsurkov - architect, senior developer
- @RebornedBrain - senior developer

Supporting roles:

- @skotopes, @DrZlo13, @hedger - general architecture advisors, code review
- @Astrrra, @doomwastaken, @Hellitron, @ImagineVagon333 - quality assurance

Special thanks:

@bettse, @pcunning, @nxv, @noproto, @AloneLiberty and everyone else who has been helping us all this time and contributing valuable knowledges, ideas and source code.
2023-10-24 12:08:09 +09:00

70 lines
No EOL
2 KiB
C

#include "nfc_util.h"
#include <furi.h>
static const uint8_t nfc_util_odd_byte_parity[256] = {
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0,
1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1,
1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1,
0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0,
1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1,
0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0,
0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1,
0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1};
void nfc_util_num2bytes(uint64_t src, uint8_t len, uint8_t* dest) {
furi_assert(dest);
furi_assert(len <= 8);
while(len--) {
dest[len] = (uint8_t)src;
src >>= 8;
}
}
uint64_t nfc_util_bytes2num(const uint8_t* src, uint8_t len) {
furi_assert(src);
furi_assert(len <= 8);
uint64_t res = 0;
while(len--) {
res = (res << 8) | (*src);
src++;
}
return res;
}
uint8_t nfc_util_even_parity32(uint32_t data) {
// data ^= data >> 16;
// data ^= data >> 8;
// return !nfc_util_odd_byte_parity[data];
return (__builtin_parity(data) & 0xFF);
}
uint8_t nfc_util_odd_parity8(uint8_t data) {
return nfc_util_odd_byte_parity[data];
}
void nfc_util_odd_parity(const uint8_t* src, uint8_t* dst, uint8_t len) {
furi_assert(src);
furi_assert(dst);
uint8_t parity = 0;
uint8_t bit = 0;
while(len--) {
parity |= nfc_util_odd_parity8(*src) << (7 - bit); // parity is MSB first
bit++;
if(bit == 8) {
*dst = parity;
dst++;
parity = 0;
bit = 0;
}
src++;
}
if(bit) {
*dst = parity;
}
}