/* Cell Scanning code for OsmocomBB */ /* (C) 2010 by Andreas Eversberg * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../../../gsmmap/geo.h" #define READ_WAIT 2, 0 #define RACH_WAIT 0, 900000 #define MIN_RXLEV_DBM -106 #define MAX_DIST 2000 enum { SCAN_STATE_PM, SCAN_STATE_SYNC, SCAN_STATE_READ, SCAN_STATE_RACH, }; /* ranges of bands */ static uint16_t basic_band_range[][2] = {{0, 124}, {512, 885}, {955, 1023}, {0, 0}}; uint16_t (*band_range)[][2] = &basic_band_range; #define INFO_FLG_PM 1 #define INFO_FLG_SYNC 2 #define INFO_FLG_SI1 4 #define INFO_FLG_SI2 8 #define INFO_FLG_SI2bis 16 #define INFO_FLG_SI2ter 32 #define INFO_FLG_SI3 64 #define INFO_FLG_SI4 128 static struct osmocom_ms *ms; static struct osmo_timer_list timer; static struct pm_info { uint16_t flags; int8_t rxlev_dbm; } pm[1024]; static int started = 0; static int state; static int8_t min_rxlev_dbm = MIN_RXLEV_DBM; static int sync_count; static int pm_index, pm_gps_valid; static double pm_gps_x, pm_gps_y, pm_gps_z; static int arfcn; static int rach_count; static FILE *logfp = NULL; extern char *logname; extern int RACH_MAX; static struct gsm48_sysinfo sysinfo; static struct log_si { uint16_t flags; uint8_t bsic; int8_t rxlev_dbm; uint16_t mcc, mnc, lac, cellid; uint8_t ta; double latitude, longitude; } log_si; struct rach_ref { uint8_t valid; uint8_t cr; uint8_t t1, t2, t3; } rach_ref; #define LOGFILE(fmt, args...) \ fprintf(logfp, fmt, ## args); #define LOGFLUSH() \ fflush(logfp); static void start_sync(void); static void start_rach(void); static void start_pm(void); static void log_gps(void) { if (!g.enable || !g.valid) return; LOGFILE("position %.8f %.8f\n", g.longitude, g.latitude); } static void log_time(void) { time_t now; if (g.enable && g.valid) now = g.gmt; else time(&now); LOGFILE("time %lu\n", now); } static void log_frame(char *tag, uint8_t *data) { int i; LOGFILE("%s", tag); for (i = 0; i < 23; i++) LOGFILE(" %02x", *data++); LOGFILE("\n"); } static void log_pm(void) { int count = 0, i; LOGFILE("[power]\n"); log_time(); log_gps(); for (i = 0; i <= 1023; i++) { if ((pm[i].flags & INFO_FLG_PM)) { if (!count) LOGFILE("arfcn %d", i); LOGFILE(" %d", pm[i].rxlev_dbm); count++; if (count == 12) { LOGFILE("\n"); count = 0; } } else { if (count) { LOGFILE("\n"); count = 0; } } } if (count) LOGFILE("\n"); LOGFILE("\n"); LOGFLUSH(); } static void log_sysinfo(void) { struct rx_meas_stat *meas = &ms->meas; struct gsm48_sysinfo *s = &sysinfo; int8_t rxlev_dbm; char ta_str[32] = ""; if (log_si.ta != 0xff) sprintf(ta_str, " TA=%d", log_si.ta); LOGP(DSUM, LOGL_INFO, "Cell: ARFCN=%d MCC=%s MNC=%s (%s, %s)%s\n", arfcn, gsm_print_mcc(s->mcc), gsm_print_mnc(s->mnc), gsm_get_mcc(s->mcc), gsm_get_mnc(s->mcc, s->mnc), ta_str); LOGFILE("[sysinfo]\n"); LOGFILE("arfcn %d\n", s->arfcn); log_time(); log_gps(); LOGFILE("bsic %d,%d\n", s->bsic >> 3, s->bsic & 7); rxlev_dbm = meas->rxlev / meas->frames - 110; LOGFILE("rxlev %d\n", rxlev_dbm); if (s->si1) log_frame("si1", s->si1_msg); if (s->si2) log_frame("si2", s->si2_msg); if (s->si2bis) log_frame("si2bis", s->si2b_msg); if (s->si2ter) log_frame("si2ter", s->si2t_msg); if (s->si3) log_frame("si3", s->si3_msg); if (s->si4) log_frame("si4", s->si4_msg); if (log_si.ta != 0xff) LOGFILE("ta %d\n", log_si.ta); LOGFILE("\n"); LOGFLUSH(); } static void timeout_cb(void *arg) { switch (state) { case SCAN_STATE_READ: LOGP(DRR, LOGL_INFO, "Timeout reading BCCH\n"); start_sync(); break; case SCAN_STATE_RACH: LOGP(DRR, LOGL_INFO, "Timeout on RACH\n"); rach_count++; start_rach(); break; } } static void stop_timer(void) { if (osmo_timer_pending(&timer)) osmo_timer_del(&timer); } static void start_timer(int sec, int micro) { stop_timer(); timer.cb = timeout_cb; timer.data = ms; osmo_timer_schedule(&timer, sec, micro); } static void start_rach(void) { struct gsm48_sysinfo *s = &sysinfo; uint8_t chan_req_val, chan_req_mask; struct msgb *nmsg; struct abis_rsl_cchan_hdr *ncch; if (rach_count == RACH_MAX) { log_sysinfo(); start_sync(); return; } state = SCAN_STATE_RACH; if (s->neci) { chan_req_mask = 0x0f; chan_req_val = 0x01; LOGP(DRR, LOGL_INFO, "CHANNEL REQUEST: %02x " "(OTHER with NECI)\n", chan_req_val); } else { chan_req_mask = 0x1f; chan_req_val = 0xe0; LOGP(DRR, LOGL_INFO, "CHANNEL REQUEST: %02x (OTHER no NECI)\n", chan_req_val); } rach_ref.valid = 0; rach_ref.cr = random(); rach_ref.cr &= chan_req_mask; rach_ref.cr |= chan_req_val; nmsg = msgb_alloc_headroom(RSL_ALLOC_SIZE+RSL_ALLOC_HEADROOM, RSL_ALLOC_HEADROOM, "GSM 04.06 RSL"); if (!nmsg) return; nmsg->l2h = nmsg->data; ncch = (struct abis_rsl_cchan_hdr *) msgb_put(nmsg, sizeof(*ncch) + 4 + 2 + 2); rsl_init_cchan_hdr(ncch, RSL_MT_CHAN_RQD); ncch->chan_nr = RSL_CHAN_RACH; ncch->data[0] = RSL_IE_REQ_REFERENCE; ncch->data[1] = rach_ref.cr; ncch->data[2] = (s->ccch_conf == 1) << 7; ncch->data[3] = 0; ncch->data[4] = RSL_IE_ACCESS_DELAY; ncch->data[5] = 0; /* no delay */ ncch->data[6] = RSL_IE_MS_POWER; ncch->data[7] = 0; /* full power */ start_timer(RACH_WAIT); lapdm_rslms_recvmsg(nmsg, &ms->lapdm_channel); } static void start_sync(void) { int rxlev_dbm = -128; int i, dist = 0; char dist_str[32] = ""; arfcn = 0xffff; for (i = 0; i <= 1023; i++) { if ((pm[i].flags & INFO_FLG_PM) && !(pm[i].flags & INFO_FLG_SYNC)) { if (pm[i].rxlev_dbm > rxlev_dbm) { rxlev_dbm = pm[i].rxlev_dbm; arfcn = i; } } } /* if GPS becomes valid, like after exitting a tunnel */ if (!pm_gps_valid && g.valid) { pm_gps_valid = 1; geo2space(&pm_gps_x, &pm_gps_y, &pm_gps_z, g.longitude, g.latitude); } if (pm_gps_valid && g.valid) { double x, y, z; geo2space(&x, &y, &z, g.longitude, g.latitude); dist = distinspace(pm_gps_x, pm_gps_y, pm_gps_z, x, y, z); sprintf(dist_str, " dist %d", (int)dist); } if (dist > MAX_DIST || arfcn == 0xffff || rxlev_dbm < min_rxlev_dbm) { memset(pm, 0, sizeof(pm)); pm_index = 0; sync_count = 0; start_pm(); return; } pm[arfcn].flags |= INFO_FLG_SYNC; LOGP(DSUM, LOGL_INFO, "Sync ARFCN %d (rxlev %d, %d syncs left)%s\n", arfcn, pm[arfcn].rxlev_dbm, sync_count--, dist_str); memset(&sysinfo, 0, sizeof(sysinfo)); sysinfo.arfcn = arfcn; state = SCAN_STATE_SYNC; l1ctl_tx_reset_req(ms, L1CTL_RES_T_FULL); l1ctl_tx_fbsb_req(ms, arfcn, L1CTL_FBSB_F_FB01SB, 100, 0, CCCH_MODE_NONE, dbm2rxlev(pm[arfcn].rxlev_dbm)); } static void start_pm(void) { uint16_t from, to; state = SCAN_STATE_PM; from = (*band_range)[pm_index][0]; to = (*band_range)[pm_index][1]; if (from == 0 && to == 0) { LOGP(DSUM, LOGL_INFO, "Measurement done\n"); pm_gps_valid = g.enable && g.valid; if (pm_gps_valid) geo2space(&pm_gps_x, &pm_gps_y, &pm_gps_z, g.longitude, g.latitude); log_pm(); start_sync(); return; } LOGP(DSUM, LOGL_INFO, "Measure from %d to %d\n", from, to); l1ctl_tx_reset_req(ms, L1CTL_RES_T_FULL); l1ctl_tx_pm_req_range(ms, from, to); } static int signal_cb(unsigned int subsys, unsigned int signal, void *handler_data, void *signal_data) { struct osmobb_meas_res *mr; struct osmobb_fbsb_res *fr; uint16_t index; if (subsys != SS_L1CTL) return 0; switch (signal) { case S_L1CTL_PM_RES: mr = signal_data; index = mr->band_arfcn & 0x3ff; pm[index].flags |= INFO_FLG_PM; pm[index].rxlev_dbm = mr->rx_lev - 110; if (pm[index].rxlev_dbm >= min_rxlev_dbm) sync_count++; // printf("rxlev %d = %d (sync_count %d)\n", index, pm[index].rxlev_dbm, sync_count); break; case S_L1CTL_PM_DONE: pm_index++; start_pm(); break; case S_L1CTL_FBSB_RESP: fr = signal_data; sysinfo.bsic = fr->bsic; state = SCAN_STATE_READ; memset(&ms->meas, 0, sizeof(ms->meas)); memset(&log_si, 0, sizeof(log_si)); log_si.flags |= INFO_FLG_SYNC; log_si.ta = 0xff; /* invalid */ start_timer(READ_WAIT); LOGP(DRR, LOGL_INFO, "Synchronized, start reading\n"); break; case S_L1CTL_FBSB_ERR: LOGP(DRR, LOGL_INFO, "Sync failed\n"); start_sync(); break; case S_L1CTL_RESET: if (started) break; started = 1; memset(pm, 0, sizeof(pm)); pm_index = 0; sync_count = 0; start_pm(); } return 0; } static int ta_result(uint8_t ta) { stop_timer(); if (ta == 0xff) LOGP(DSUM, LOGL_INFO, "Got assignment reject\n"); else { LOGP(DSUM, LOGL_DEBUG, "Got assignment TA = %d\n", ta); log_si.ta = ta; } log_sysinfo(); start_sync(); return 0; } /* match request reference agains request */ static int match_ra(struct osmocom_ms *ms, struct gsm48_req_ref *ref) { uint8_t ia_t1, ia_t2, ia_t3; /* filter confirmed RACH requests only */ if (rach_ref.valid && ref->ra == rach_ref.cr) { ia_t1 = ref->t1; ia_t2 = ref->t2; ia_t3 = (ref->t3_high << 3) | ref->t3_low; if (ia_t1 == rach_ref.t1 && ia_t2 == rach_ref.t2 && ia_t3 == rach_ref.t3) { LOGP(DRR, LOGL_INFO, "request %02x matches " "(fn=%d,%d,%d)\n", ref->ra, ia_t1, ia_t2, ia_t3); return 1; } else LOGP(DRR, LOGL_INFO, "request %02x matches but not " "frame number (IMM.ASS fn=%d,%d,%d != RACH " "fn=%d,%d,%d)\n", ref->ra, ia_t1, ia_t2, ia_t3, rach_ref.t1, rach_ref.t2, rach_ref.t3); } return 0; } /* 9.1.18 IMMEDIATE ASSIGNMENT is received */ static int imm_ass(struct osmocom_ms *ms, struct msgb *msg) { struct gsm48_imm_ass *ia = msgb_l3(msg); LOGP(DRR, LOGL_INFO, "IMMEDIATE ASSIGNMENT:\n"); if (state != SCAN_STATE_RACH) { LOGP(DRR, LOGL_INFO, "Not for us, no request.\n"); return 0; } /* request ref */ if (match_ra(ms, &ia->req_ref)) { return ta_result(ia->timing_advance); } LOGP(DRR, LOGL_INFO, "Request, but not for us.\n"); return 0; } /* 9.1.19 IMMEDIATE ASSIGNMENT EXTENDED is received */ static int imm_ass_ext(struct osmocom_ms *ms, struct msgb *msg) { struct gsm48_imm_ass_ext *ia = msgb_l3(msg); LOGP(DRR, LOGL_INFO, "IMMEDIATE ASSIGNMENT EXTENDED:\n"); if (state != SCAN_STATE_RACH) { LOGP(DRR, LOGL_INFO, "Not for us, no request.\n"); return 0; } /* request ref 1 */ if (match_ra(ms, &ia->req_ref1)) { return ta_result(ia->timing_advance1); } /* request ref 2 */ if (match_ra(ms, &ia->req_ref2)) { return ta_result(ia->timing_advance2); } LOGP(DRR, LOGL_INFO, "Request, but not for us.\n"); return 0; } /* 9.1.20 IMMEDIATE ASSIGNMENT REJECT is received */ static int imm_ass_rej(struct osmocom_ms *ms, struct msgb *msg) { struct gsm48_imm_ass_rej *ia = msgb_l3(msg); int i; struct gsm48_req_ref *req_ref; LOGP(DRR, LOGL_INFO, "IMMEDIATE ASSIGNMENT REJECT:\n"); if (state != SCAN_STATE_RACH) { LOGP(DRR, LOGL_INFO, "Not for us, no request.\n"); return 0; } for (i = 0; i < 4; i++) { /* request reference */ req_ref = (struct gsm48_req_ref *) (((uint8_t *)&ia->req_ref1) + i * 4); LOGP(DRR, LOGL_INFO, "IMMEDIATE ASSIGNMENT REJECT " "(ref 0x%02x)\n", req_ref->ra); if (match_ra(ms, req_ref)) { return ta_result(0xff); } } return 0; } /* receive CCCH at RR layer */ static int pch_agch(struct osmocom_ms *ms, struct msgb *msg) { struct gsm48_system_information_type_header *sih = msgb_l3(msg); switch (sih->system_information) { case GSM48_MT_RR_PAG_REQ_1: case GSM48_MT_RR_PAG_REQ_2: case GSM48_MT_RR_PAG_REQ_3: return 0; case GSM48_MT_RR_IMM_ASS: return imm_ass(ms, msg); case GSM48_MT_RR_IMM_ASS_EXT: return imm_ass_ext(ms, msg); case GSM48_MT_RR_IMM_ASS_REJ: return imm_ass_rej(ms, msg); default: return -EINVAL; } } /* check if sysinfo is complete, change to RACH state */ static int new_sysinfo(void) { struct gsm48_sysinfo *s = &sysinfo; /* restart timer */ start_timer(READ_WAIT); /* mandatory */ if (!s->si1 || !s->si2 || !s->si3 || !s->si4) { LOGP(DRR, LOGL_INFO, "not all mandatory SI received\n"); return 0; } /* extended band */ if (s->nb_ext_ind_si2 && !s->si2bis) { LOGP(DRR, LOGL_INFO, "extended ba, but si2bis not received\n"); return 0; } /* 2ter */ if (s->si2ter_ind && !s->si2ter) { LOGP(DRR, LOGL_INFO, "si2ter_ind, but si2ter not received\n"); return 0; } LOGP(DRR, LOGL_INFO, "Sysinfo complete\n"); stop_timer(); rach_count = 0; start_rach(); return 0; } /* receive BCCH at RR layer */ static int bcch(struct osmocom_ms *ms, struct msgb *msg) { struct gsm48_sysinfo *s = &sysinfo; struct gsm48_system_information_type_header *sih = msgb_l3(msg); uint8_t ccch_mode; if (msgb_l3len(msg) != 23) { LOGP(DRR, LOGL_NOTICE, "Invalid BCCH message length\n"); return -EINVAL; } switch (sih->system_information) { case GSM48_MT_RR_SYSINFO_1: if (!memcmp(sih, s->si1_msg, sizeof(s->si1_msg))) return 0; LOGP(DRR, LOGL_INFO, "New SYSTEM INFORMATION 1\n"); gsm48_decode_sysinfo1(s, (struct gsm48_system_information_type_1 *) sih, msgb_l3len(msg)); return new_sysinfo(); case GSM48_MT_RR_SYSINFO_2: if (!memcmp(sih, s->si2_msg, sizeof(s->si2_msg))) return 0; LOGP(DRR, LOGL_INFO, "New SYSTEM INFORMATION 2\n"); gsm48_decode_sysinfo2(s, (struct gsm48_system_information_type_2 *) sih, msgb_l3len(msg)); return new_sysinfo(); case GSM48_MT_RR_SYSINFO_2bis: if (!memcmp(sih, s->si2b_msg, sizeof(s->si2b_msg))) return 0; LOGP(DRR, LOGL_INFO, "New SYSTEM INFORMATION 2bis\n"); gsm48_decode_sysinfo2bis(s, (struct gsm48_system_information_type_2bis *) sih, msgb_l3len(msg)); return new_sysinfo(); case GSM48_MT_RR_SYSINFO_2ter: if (!memcmp(sih, s->si2t_msg, sizeof(s->si2t_msg))) return 0; LOGP(DRR, LOGL_INFO, "New SYSTEM INFORMATION 2ter\n"); gsm48_decode_sysinfo2ter(s, (struct gsm48_system_information_type_2ter *) sih, msgb_l3len(msg)); return new_sysinfo(); case GSM48_MT_RR_SYSINFO_3: if (!memcmp(sih, s->si3_msg, sizeof(s->si3_msg))) return 0; LOGP(DRR, LOGL_INFO, "New SYSTEM INFORMATION 3\n"); gsm48_decode_sysinfo3(s, (struct gsm48_system_information_type_3 *) sih, msgb_l3len(msg)); ccch_mode = (s->ccch_conf == 1) ? CCCH_MODE_COMBINED : CCCH_MODE_NON_COMBINED; LOGP(DRR, LOGL_INFO, "Changing CCCH_MODE to %d\n", ccch_mode); l1ctl_tx_ccch_mode_req(ms, ccch_mode); return new_sysinfo(); case GSM48_MT_RR_SYSINFO_4: if (!memcmp(sih, s->si4_msg, sizeof(s->si4_msg))) return 0; LOGP(DRR, LOGL_INFO, "New SYSTEM INFORMATION 4\n"); gsm48_decode_sysinfo4(s, (struct gsm48_system_information_type_4 *) sih, msgb_l3len(msg)); return new_sysinfo(); default: return -EINVAL; } } static int unit_data_ind(struct osmocom_ms *ms, struct msgb *msg) { struct abis_rsl_rll_hdr *rllh = msgb_l2(msg); struct tlv_parsed tv; uint8_t ch_type, ch_subch, ch_ts; DEBUGP(DRSL, "RSLms UNIT DATA IND chan_nr=0x%02x link_id=0x%02x\n", rllh->chan_nr, rllh->link_id); rsl_tlv_parse(&tv, rllh->data, msgb_l2len(msg)-sizeof(*rllh)); if (!TLVP_PRESENT(&tv, RSL_IE_L3_INFO)) { DEBUGP(DRSL, "UNIT_DATA_IND without L3 INFO ?!?\n"); return -EIO; } msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO); if (state != SCAN_STATE_READ && state != SCAN_STATE_RACH) { return -EINVAL; } rsl_dec_chan_nr(rllh->chan_nr, &ch_type, &ch_subch, &ch_ts); switch (ch_type) { case RSL_CHAN_PCH_AGCH: return pch_agch(ms, msg); case RSL_CHAN_BCCH: return bcch(ms, msg); #if 0 case RSL_CHAN_Bm_ACCHs: case RSL_CHAN_Lm_ACCHs: case RSL_CHAN_SDCCH4_ACCH: case RSL_CHAN_SDCCH8_ACCH: return rx_acch(ms, msg); #endif default: LOGP(DRSL, LOGL_NOTICE, "RSL with chan_nr 0x%02x unknown.\n", rllh->chan_nr); return -EINVAL; } } static int rcv_rll(struct osmocom_ms *ms, struct msgb *msg) { struct abis_rsl_rll_hdr *rllh = msgb_l2(msg); int msg_type = rllh->c.msg_type; if (msg_type == RSL_MT_UNIT_DATA_IND) { unit_data_ind(ms, msg); } else LOGP(DRSL, LOGL_NOTICE, "RSLms message unhandled\n"); msgb_free(msg); return 0; } int chan_conf(struct osmocom_ms *ms, struct msgb *msg) { struct abis_rsl_cchan_hdr *ch = msgb_l2(msg); struct gsm48_req_ref *ref = (struct gsm48_req_ref *) (ch->data + 1); if (msgb_l2len(msg) < sizeof(*ch) + sizeof(*ref)) { LOGP(DRR, LOGL_ERROR, "CHAN_CNF too slort\n"); return -EINVAL; } rach_ref.valid = 1; rach_ref.t1 = ref->t1; rach_ref.t2 = ref->t2; rach_ref.t3 = ref->t3_low | (ref->t3_high << 3); return 0; } static int rcv_cch(struct osmocom_ms *ms, struct msgb *msg) { struct abis_rsl_cchan_hdr *ch = msgb_l2(msg); int msg_type = ch->c.msg_type; int rc; LOGP(DRSL, LOGL_INFO, "Received '%s' from layer1\n", rsl_msg_name(msg_type)); if (state == SCAN_STATE_RACH && msg_type == RSL_MT_CHAN_CONF) { rc = chan_conf(ms, msg); msgb_free(msg); return rc; } LOGP(DRSL, LOGL_NOTICE, "RSLms message unhandled\n"); msgb_free(msg); return 0; } static int rcv_rsl(struct msgb *msg, struct lapdm_entity *le, void *l3ctx) { struct osmocom_ms *ms = l3ctx; struct abis_rsl_common_hdr *rslh = msgb_l2(msg); int rc = 0; switch (rslh->msg_discr & 0xfe) { case ABIS_RSL_MDISC_RLL: rc = rcv_rll(ms, msg); break; case ABIS_RSL_MDISC_COM_CHAN: rc = rcv_cch(ms, msg); break; default: LOGP(DRSL, LOGL_NOTICE, "unknown RSLms msg_discr 0x%02x\n", rslh->msg_discr); msgb_free(msg); rc = -EINVAL; break; } return rc; } int scan_init(struct osmocom_ms *_ms) { ms = _ms; osmo_signal_register_handler(SS_L1CTL, &signal_cb, NULL); memset(&timer, 0, sizeof(timer)); lapdm_channel_set_l3(&ms->lapdm_channel, &rcv_rsl, ms); g.enable = 1; osmo_gps_init(); if (osmo_gps_open()) g.enable = 0; if (!strcmp(logname, "-")) logfp = stdout; else logfp = fopen(logname, "a"); if (!logfp) { fprintf(stderr, "Failed to open logfile '%s'\n", logname); scan_exit(); return -errno; } LOGP(DSUM, LOGL_INFO, "Scanner initialized\n"); return 0; } int scan_exit(void) { LOGP(DSUM, LOGL_INFO, "Scanner exit\n"); if (g.valid) osmo_gps_close(); if (logfp) fclose(logfp); osmo_signal_unregister_handler(SS_L1CTL, &signal_cb, NULL); stop_timer(); return 0; }