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Diffstat (limited to 'lib/decoding/osmocom/coding/gsm0503_parity.c')
-rw-r--r-- | lib/decoding/osmocom/coding/gsm0503_parity.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/lib/decoding/osmocom/coding/gsm0503_parity.c b/lib/decoding/osmocom/coding/gsm0503_parity.c new file mode 100644 index 0000000..50977f7 --- /dev/null +++ b/lib/decoding/osmocom/coding/gsm0503_parity.c @@ -0,0 +1,132 @@ +/* + * (C) 2013 by Andreas Eversberg <jolly@eversberg.eu> + * (C) 2016 by Tom Tsou <tom.tsou@ettus.com> + * + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <stdint.h> + +#include <osmocom/core/crcgen.h> +#include "gsm0503_parity.h" + +/* + * GSM (SACCH) parity (FIRE code) + * + * g(x) = (x^23 + 1)(x^17 + x^3 + 1) + * = x^40 + x^26 + x^23 + x^17 + x^3 + a1 + */ +const struct osmo_crc64gen_code gsm0503_fire_crc40 = { + .bits = 40, + .poly = 0x0004820009ULL, + .init = 0x0000000000ULL, + .remainder = 0xffffffffffULL, +}; + +/* + * GSM PDTCH CS-2, CS-3, CS-4 parity + * + * g(x) = x^16 + x^12 + x^5 + 1 + */ +const struct osmo_crc16gen_code gsm0503_cs234_crc16 = { + .bits = 16, + .poly = 0x1021, + .init = 0x0000, + .remainder = 0xffff, +}; + +/* + * EDGE MCS header parity + * + */ +const struct osmo_crc8gen_code gsm0503_mcs_crc8_hdr = { + .bits = 8, + .poly = 0x49, + .init = 0x00, + .remainder = 0xff, +}; + +/* + * EDGE MCS data parity + * + */ +const struct osmo_crc16gen_code gsm0503_mcs_crc12 = { + .bits = 12, + .poly = 0x0d31, + .init = 0x0000, + .remainder = 0x0fff, +}; + +/* + * GSM RACH parity + * + * g(x) = x^6 + x^5 + x^3 + x^2 + x^1 + 1 + */ +const struct osmo_crc8gen_code gsm0503_rach_crc6 = { + .bits = 6, + .poly = 0x2f, + .init = 0x00, + .remainder = 0x3f, +}; + +/* + * GSM SCH parity + * + * g(x) = x^10 + x^8 + x^6 + x^5 + x^4 + x^2 + 1 + */ +const struct osmo_crc16gen_code gsm0503_sch_crc10 = { + .bits = 10, + .poly = 0x175, + .init = 0x000, + .remainder = 0x3ff, +}; + +/* + * GSM TCH FR/HR/EFR parity + * + * g(x) = x^3 + x + 1 + */ +const struct osmo_crc8gen_code gsm0503_tch_fr_crc3 = { + .bits = 3, + .poly = 0x3, + .init = 0x0, + .remainder = 0x7, +}; + +/* + * GSM TCH EFR parity + * + * g(x) = x^8 + x^4 + x^3 + x^2 + 1 + */ +const struct osmo_crc8gen_code gsm0503_tch_efr_crc8 = { + .bits = 8, + .poly = 0x1d, + .init = 0x00, + .remainder = 0x00, +}; + +/* + * GSM AMR parity + * + * g(x) = x^6 + x^5 + x^3 + x^2 + x^1 + 1 + */ +const struct osmo_crc8gen_code gsm0503_amr_crc6 = { + .bits = 6, + .poly = 0x2f, + .init = 0x00, + .remainder = 0x3f, +}; |