1 files changed, 103 insertions, 0 deletions
diff --git a/src/osmo-bts-trx/gsm0503_parity.c b/src/osmo-bts-trx/gsm0503_parity.c
new file mode 100644
index 00000000..ba2e144a
--- /dev/null
+++ b/src/osmo-bts-trx/gsm0503_parity.c
@@ -0,0 +1,103 @@
+
+#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,
+};
+
+
+/*
+ * 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,
+};
+