[paging] Keep a copy of the Control Channel Description in the bts struct

- Initialize Control Channel Description of SI3 
- Patch the table
- Setting ATT now is easy
- Paging can now extract all required information... to determine
  the right paging group.

3 files changed, 27 insertions, 1 deletions

diff --git a/include/openbsc/gsm_04_08.h b/include/openbsc/gsm_04_08.h
index e44b061e2..8033942e3 100644
--- a/include/openbsc/gsm_04_08.h
+++ b/include/openbsc/gsm_04_08.h
@@ -2,6 +2,7 @@
 #define _GSM_04_08_H
 
 /* GSM TS 04.08  definitions */
+struct gsm_lchan;
 
 /* Chapter 10.5.2.5 */
 struct gsm48_chan_desc {
@@ -86,6 +87,17 @@ struct gsm48_rach_control {
 	u_int8_t t3;
 } __attribute__ ((packed));
 
+/* Section 10.5.2.11 Control Channel Description , Figure 10.5.33 */
+struct gsm48_control_channel_descr {
+	u_int8_t ccch_conf :3,
+		bs_ag_blks_res :3,
+		att :1,
+		spare1 :1;
+	u_int8_t bs_pa_mfrms : 3,
+		spare2 :5;
+	u_int8_t t3212;
+} __attribute__ ((packed));
+
 /* Section 9.2.9 CM service request */
 struct gsm48_service_request {
 	u_int8_t cm_service_type : 4,
@@ -118,7 +130,7 @@ struct gsm48_system_information_type_3 {
 	struct gsm48_system_information_type_header header;
 	u_int16_t cell_identity;
 	struct gsm48_loc_area_id lai;
-	u_int8_t control_channel_description[3];
+	struct gsm48_control_channel_descr control_channel_desc;
 	u_int8_t cell_options;
 	u_int8_t cell_selection[2];
 	struct gsm48_rach_control rach_control;
diff --git a/include/openbsc/gsm_data.h b/include/openbsc/gsm_data.h
index 2173c51c5..621f11604 100644
--- a/include/openbsc/gsm_data.h
+++ b/include/openbsc/gsm_data.h
@@ -4,6 +4,7 @@
 #include <sys/types.h>
 
 #include <openbsc/timer.h>
+#include <openbsc/gsm_04_08.h>
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
 
@@ -191,6 +192,8 @@ struct gsm_bts {
 	/* number of this BTS on given E1 link */
 	u_int8_t bts_nr;
 
+	struct gsm48_control_channel_descr chan_desc;
+
 	/* CCCH is on C0 */
 	struct gsm_bts_trx *c0;
 	/* transceivers */
diff --git a/src/bsc_hack.c b/src/bsc_hack.c
index db8a68345..8d02d8939 100644
--- a/src/bsc_hack.c
+++ b/src/bsc_hack.c
@@ -642,6 +642,9 @@ static void patch_tables(struct gsm_bts *bts)
 	type_4->data[2] &= 0xf0;
 	type_4->data[2] |= arfcn_high;
 	type_4->data[3] = arfcn_low;
+
+	/* patch Control Channel Description 10.5.2.11 */
+	type_3->control_channel_desc = bts->chan_desc;
 }
 
 
@@ -681,6 +684,14 @@ static int bootstrap_network(void)
 	bts = &gsmnet->bts[0];
 	bts->location_area_code = 1;
 	bts->trx[0].arfcn = ARFCN;
+
+	/* Control Channel Description */
+	memset(&bts->chan_desc, 0, sizeof(struct gsm48_control_channel_descr));
+	bts->chan_desc.att = 0;
+	bts->chan_desc.ccch_conf = RSL_BCCH_CCCH_CONF_1_C;
+	bts->chan_desc.bs_pa_mfrms = RSL_BS_PA_MFRMS_5;
+	bts->chan_desc.t3212 = 0;
+
 	patch_tables(bts);
 
 	paging_bts = page_allocate(bts);