diff options
Diffstat (limited to 'src/lisp/ao_lisp_make_const.c')
| -rw-r--r-- | src/lisp/ao_lisp_make_const.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/lisp/ao_lisp_make_const.c b/src/lisp/ao_lisp_make_const.c index 0a8c9d07..6a29f402 100644 --- a/src/lisp/ao_lisp_make_const.c +++ b/src/lisp/ao_lisp_make_const.c @@ -86,6 +86,33 @@ is_atom(int offset) return 0; } +#define AO_FEC_CRC_INIT 0xffff + +static inline uint16_t +ao_fec_crc_byte(uint8_t byte, uint16_t crc) +{ + uint8_t bit; + + for (bit = 0; bit < 8; bit++) { + if (((crc & 0x8000) >> 8) ^ (byte & 0x80)) + crc = (crc << 1) ^ 0x8005; + else + crc = (crc << 1); + byte <<= 1; + } + return crc; +} + +uint16_t +ao_fec_crc(const uint8_t *bytes, uint8_t len) +{ + uint16_t crc = AO_FEC_CRC_INIT; + + while (len--) + crc = ao_fec_crc_byte(*bytes++, crc); + return crc; +} + int main(int argc, char **argv) { @@ -126,6 +153,7 @@ main(int argc, char **argv) printf("extern const uint8_t ao_lisp_const[AO_LISP_POOL_CONST] __attribute__((aligned(4)));\n"); printf("#define ao_builtin_atoms 0x%04x\n", ao_lisp_atom_poly(ao_lisp_atoms)); printf("#define ao_builtin_frame 0x%04x\n", ao_lisp_frame_poly(ao_lisp_frame_global)); + printf("#define ao_lisp_const_checksum ((uint16_t) 0x%04x)\n", ao_fec_crc(ao_lisp_const, ao_lisp_top)); for (a = ao_lisp_atoms; a; a = ao_lisp_poly_atom(a->next)) { char *n = a->name, c; |