Move MIB to MAC

The MasterInformationBlock is handled at the DU and sent to the CU in
the F1 Setup Response. Hence, move it down to the MAC. Furthermore:

- Change type because MIB_PDU_t is 4G type
- Simplify schedule_nr_mib()

doc/SW_archi.md

@@ -211,7 +211,7 @@ The scheduler also calls "run_pdcp()", as this is not a autonomous thread, it ne
 After calling run_pdcp, it updates "rlc" time data but it doesn't actually process rlc 
 it sends a iiti message to activate the thread for RRC, the answer will be asynchronous in ????  
 
-Calls schedule_nr_mib() that calls mac_rrc_nr_data_req() to fill MIB,  
+Calls schedule_nr_mib() that fills MIB,
 
 Calls schedule_nr_prach() which schedules the (fixed) PRACH region one frame in
 advance.

openair1/SIMULATION/NR_PHY/ulsim.c

@@ -652,7 +652,6 @@ int main(int argc, char *argv[])
   gNB->if_inst->NR_PHY_config_req = nr_phy_config_request;
   // common configuration
   nr_mac_config_scc(RC.nrmac[0], conf.pdsch_AntennaPorts, n_tx, 0, 6);
-  nr_mac_config_mib(RC.nrmac[0], mib);
   // UE dedicated configuration
   nr_mac_add_test_ue(RC.nrmac[0], secondaryCellGroup->spCellConfig->reconfigurationWithSync->newUE_Identity, secondaryCellGroup);
   frame_parms->nb_antennas_tx = 1;

openair2/GNB_APP/gnb_config.c

@@ -1960,9 +1960,10 @@ int RC_config_trigger_F1Setup()
         req->cell[0].info.plmn.mnc_digit_length,
         req->cell[0].info.nr_cellid);
 
-  gNB_RRC_INST *rrc = RC.nrrrc[0];
-  DevAssert(rrc);
-  const NR_ServingCellConfigCommon_t *scc = RC.nrmac[0]->common_channels[0].ServingCellConfigCommon;
+
+  gNB_MAC_INST *mac = RC.nrmac[0];
+  DevAssert(mac);
+  const NR_ServingCellConfigCommon_t *scc = mac->common_channels[0].ServingCellConfigCommon;
   DevAssert(scc != NULL);
   req->cell[0].info.nr_pci = *scc->physCellId;
   LOG_W(GNB_APP, "no slices transported via F1 Setup Request!\n");
@@ -1992,16 +1993,18 @@ int RC_config_trigger_F1Setup()
 
   req->cell[0].info.measurement_timing_information = "0";
 
-  DevAssert(rrc->carrier.mib != NULL);
+  DevAssert(mac->common_channels[0].mib != NULL);
   int buf_len = 3; // this is what we assume in monolithic
   req->cell[0].sys_info = calloc(1, sizeof(*req->cell[0].sys_info));
   AssertFatal(req->cell[0].sys_info != NULL, "out of memory\n");
   f1ap_gnb_du_system_info_t *sys_info = req->cell[0].sys_info;
   sys_info->mib = calloc(buf_len, sizeof(*sys_info->mib));
   DevAssert(sys_info->mib != NULL);
-  sys_info->mib_length = encode_MIB_NR(rrc->carrier.mib, 0, sys_info->mib, buf_len);
+  sys_info->mib_length = encode_MIB_NR(mac->common_channels[0].mib, 0, sys_info->mib, buf_len);
   DevAssert(sys_info->mib_length == buf_len);
 
+  gNB_RRC_INST *rrc = RC.nrrrc[0];
+  DevAssert(rrc);
   NR_BCCH_DL_SCH_Message_t *bcch_message = NULL;
   asn_codec_ctx_t st = {100 * 1000};
   asn_dec_rval_t dec_rval = uper_decode_complete(&st,
@@ -2026,7 +2029,6 @@ int RC_config_trigger_F1Setup()
   if (LOG_DEBUGFLAG(DEBUG_ASN1))
     xer_fprint(stdout, &asn_DEF_NR_SIB1, (void *)bcch_message->message.choice.c1->choice.systemInformationBlockType1);
 
-  gNB_MAC_INST *mac = RC.nrmac[0];
   mac->mac_rrc.f1_setup_request(req);
   mac->f1_config.setup_req = req;
 

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.c

@@ -4105,7 +4105,7 @@ uint32_t get_Y(const NR_SearchSpace_t *ss, int slot, rnti_t rnti) {
 
 void get_type0_PDCCH_CSS_config_parameters(NR_Type0_PDCCH_CSS_config_t *type0_PDCCH_CSS_config,
                                            frame_t frameP,
-                                           NR_MIB_t *mib,
+                                           const NR_MIB_t *mib,
                                            uint8_t num_slot_per_frame,
                                            uint8_t ssb_subcarrier_offset,
                                            uint16_t ssb_start_symbol,

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.h

@@ -207,7 +207,7 @@ uint32_t nr_compute_tbslbrm(uint16_t table,
 
 void get_type0_PDCCH_CSS_config_parameters(NR_Type0_PDCCH_CSS_config_t *type0_PDCCH_CSS_config,
                                            frame_t frameP,
-                                           NR_MIB_t *mib,
+                                           const NR_MIB_t *mib,
                                            uint8_t num_slot_per_frame,
                                            uint8_t ssb_subcarrier_offset,
                                            uint16_t ssb_start_symbol,

openair2/LAYER2/NR_MAC_gNB/config.c

@@ -560,18 +560,6 @@ void nr_mac_config_scc(gNB_MAC_INST *nrmac,
   NR_SCHED_UNLOCK(&nrmac->sched_lock);
 }
 
-void nr_mac_config_mib(gNB_MAC_INST *nrmac, NR_BCCH_BCH_Message_t *mib)
-{
-  DevAssert(nrmac != NULL);
-  DevAssert(mib != NULL);
-  NR_SCHED_LOCK(&nrmac->sched_lock);
-  NR_COMMON_channels_t *cc = &nrmac->common_channels[0];
-
-  AssertFatal(cc->mib == NULL, "logic bug: updated MIB multiple times\n");
-  cc->mib = mib;
-  NR_SCHED_UNLOCK(&nrmac->sched_lock);
-}
-
 void nr_mac_config_sib1(gNB_MAC_INST *nrmac, NR_BCCH_DL_SCH_Message_t *sib1)
 {
   DevAssert(nrmac != NULL);

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c

@@ -105,19 +105,26 @@ static void fill_ssb_vrb_map(NR_COMMON_channels_t *cc, int rbStart, int ssb_subc
     vrb_map[rbStart + rb] = SL_to_bitmap(symStart % NR_SYMBOLS_PER_SLOT, 4);
 }
 
+static int encode_mib(NR_BCCH_BCH_Message_t *mib, frame_t frame, uint8_t *buffer, int buf_size)
+{
+  int encode_size = 3;
+  AssertFatal(buf_size >= encode_size, "buffer of size %d too small, need 3 bytes\n", buf_size);
+  int encoded = encode_MIB_NR(mib, frame, buffer, encode_size);
+  DevAssert(encoded == encode_size);
+  return encode_size;
+}
+
 void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t slotP, nfapi_nr_dl_tti_request_t *DL_req)
 {
   gNB_MAC_INST *gNB = RC.nrmac[module_idP];
   /* already mutex protected: held in gNB_dlsch_ulsch_scheduler() */
-  NR_COMMON_channels_t *cc;
   nfapi_nr_dl_tti_request_body_t *dl_req;
-  NR_MIB_t *mib = RC.nrrrc[module_idP]->carrier.mib->message.choice.mib;
   uint8_t num_tdd_period,num_ssb;
-  int mib_sdu_length;
   int CC_id;
 
   for (CC_id = 0; CC_id < MAX_NUM_CCs; CC_id++) {
-    cc = &gNB->common_channels[CC_id];
+    NR_COMMON_channels_t *cc= &gNB->common_channels[CC_id];
+    const NR_MIB_t *mib = cc->mib->message.choice.mib;
     NR_ServingCellConfigCommon_t *scc = cc->ServingCellConfigCommon;
     const int slots_per_frame = nr_slots_per_frame[*scc->ssbSubcarrierSpacing];
     dl_req = &DL_req->dl_tti_request_body;
@@ -125,8 +132,7 @@ void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t slotP,
     // get MIB every 8 frames
     if(((slotP == 0) && (frameP & 7) == 0) ||
        gNB->first_MIB) {
-
-      mib_sdu_length = mac_rrc_nr_data_req(module_idP, CC_id, frameP, MIBCH, 0, 1, &cc->MIB_pdu.payload[0]);
+      int mib_sdu_length = encode_mib(cc->mib, frameP, cc->MIB_pdu, sizeof(cc->MIB_pdu));
 
       // flag to avoid sending an empty MIB in the first frames of execution since gNB doesn't get at the beginning in frame 0 slot 0
       gNB->first_MIB = false;
@@ -139,6 +145,8 @@ void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t slotP,
             mib_sdu_length);
     }
 
+    uint32_t mib_pdu = (*(uint32_t *)cc->MIB_pdu) & ((1 << 24) - 1);
+
     int8_t ssb_period = *scc->ssb_periodicityServingCell;
     uint8_t ssb_frame_periodicity = 1;  // every how many frames SSB are generated
 
@@ -175,7 +183,7 @@ void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t slotP,
               // if start symbol is in current slot, schedule current SSB, fill VRB map and call get_type0_PDCCH_CSS_config_parameters
               if ((ssb_start_symbol/14) == rel_slot){
                 const int prb_offset = offset_pointa >> scs;
-                schedule_ssb(frameP, slotP, scc, dl_req, i_ssb, ssbSubcarrierOffset, offset_pointa, (*(uint32_t*)cc->MIB_pdu.payload) & ((1<<24)-1));
+                schedule_ssb(frameP, slotP, scc, dl_req, i_ssb, ssbSubcarrierOffset, offset_pointa, mib_pdu);
                 fill_ssb_vrb_map(cc, prb_offset, ssbSubcarrierOffset, ssb_start_symbol, CC_id);
                 if (get_softmodem_params()->sa == 1) {
                   get_type0_PDCCH_CSS_config_parameters(&gNB->type0_PDCCH_CSS_config[i_ssb],
@@ -204,7 +212,7 @@ void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t slotP,
               // if start symbol is in current slot, schedule current SSB, fill VRB map and call get_type0_PDCCH_CSS_config_parameters
               if ((ssb_start_symbol/14) == rel_slot){
                 const int prb_offset = offset_pointa >> scs;
-                schedule_ssb(frameP, slotP, scc, dl_req, i_ssb, ssbSubcarrierOffset, offset_pointa, (*(uint32_t*)cc->MIB_pdu.payload) & ((1<<24)-1));
+                schedule_ssb(frameP, slotP, scc, dl_req, i_ssb, ssbSubcarrierOffset, offset_pointa, mib_pdu);
                 fill_ssb_vrb_map(cc, prb_offset, ssbSubcarrierOffset, ssb_start_symbol, CC_id);
                 if (get_softmodem_params()->sa == 1) {
                   get_type0_PDCCH_CSS_config_parameters(&gNB->type0_PDCCH_CSS_config[i_ssb],
@@ -234,7 +242,7 @@ void schedule_nr_mib(module_id_t module_idP, frame_t frameP, sub_frame_t slotP,
               // if start symbol is in current slot, schedule current SSB, fill VRB map and call get_type0_PDCCH_CSS_config_parameters
               if ((ssb_start_symbol/14) == rel_slot){
                 const int prb_offset = offset_pointa >> (scs-2); // reference 60kHz
-                schedule_ssb(frameP, slotP, scc, dl_req, i_ssb, ssbSubcarrierOffset, offset_pointa, (*(uint32_t*)cc->MIB_pdu.payload) & ((1<<24)-1));
+                schedule_ssb(frameP, slotP, scc, dl_req, i_ssb, ssbSubcarrierOffset, offset_pointa, mib_pdu);
                 fill_ssb_vrb_map(cc, prb_offset, ssbSubcarrierOffset >> (scs - 2), ssb_start_symbol, CC_id);
                 const NR_TDD_UL_DL_Pattern_t *tdd = &scc->tdd_UL_DL_ConfigurationCommon->pattern1;
                 const int n_slots_frame = nr_slots_per_frame[*scc->ssbSubcarrierSpacing];

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -50,7 +50,6 @@ void nr_mac_config_scc(gNB_MAC_INST *nrmac,
                        int pusch_AntennaPorts,
                        int sib1_tda,
                        int minRXTXTIMEpdsch);
-void nr_mac_config_mib(gNB_MAC_INST *nrmac, NR_BCCH_BCH_Message_t *mib);
 void nr_mac_config_sib1(gNB_MAC_INST *nrmac, NR_BCCH_DL_SCH_Message_t *sib1);
 bool nr_mac_add_test_ue(gNB_MAC_INST *nrmac, uint32_t rnti, NR_CellGroupConfig_t *CellGroup);
 bool nr_mac_prepare_ra_ue(gNB_MAC_INST *nrmac, uint32_t rnti, NR_CellGroupConfig_t *CellGroup);

openair2/LAYER2/NR_MAC_gNB/main.c

@@ -245,6 +245,7 @@ void mac_top_init_gNB(ngran_node_t node_type, NR_ServingCellConfigCommon_t *scc,
       RC.nrmac[i]->common_channels[0].pre_ServingCellConfig = scd;
 
       RC.nrmac[i]->first_MIB = true;
+      RC.nrmac[i]->common_channels[0].mib = get_new_MIB_NR(scc);
 
       RC.nrmac[i]->cset0_bwp_start = 0;
       RC.nrmac[i]->cset0_bwp_size = 0;

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -225,7 +225,7 @@ typedef struct {
   NR_ARFCN_ValueEUTRA_t ul_CarrierFreq;
   long ul_Bandwidth;
   /// Outgoing MIB PDU for PHY
-  MIB_PDU MIB_pdu;
+  uint8_t MIB_pdu[3];
   /// Outgoing BCCH pdu for PHY
   BCCH_PDU BCCH_pdu;
   /// Outgoing BCCH DCI allocation

openair2/RRC/NR/L2_nr_interface.c

@@ -74,13 +74,7 @@ uint16_t mac_rrc_nr_data_req(const module_id_t Mod_idP,
   // MIBCH
   if ((Srb_id & RAB_OFFSET) == MIBCH) {
 
-    int encode_size = 3;
-    rrc_gNB_carrier_data_t *carrier = &RC.nrrrc[Mod_idP]->carrier;
-    int encoded = encode_MIB_NR(carrier->mib, frameP, buffer_pP, encode_size);
-    DevAssert(encoded == encode_size);
-    LOG_D(NR_RRC, "MIB PDU buffer_pP[0]=%x , buffer_pP[1]=%x, buffer_pP[2]=%x\n", buffer_pP[0], buffer_pP[1],
-          buffer_pP[2]);
-    return encode_size;
+    DevAssert(false);
   }
 
   if ((Srb_id & RAB_OFFSET) == BCCH) {

openair2/RRC/NR/nr_rrc_defs.h

@@ -331,7 +331,6 @@ typedef struct {
   uint8_t                                   *SIB23;
   uint8_t                                   sizeof_SIB23;
 
-  NR_BCCH_BCH_Message_t                    *mib;
   NR_SIB1_t                                *siblock1_DU;
   NR_SIB1_t                                *sib1;
   NR_SIB2_t                                *sib2;
@@ -376,6 +375,7 @@ typedef struct cucp_cuup_if_s {
 
 typedef struct nr_rrc_du_container_t {
   f1ap_setup_req_t *setup_req;
+  NR_MIB_t *mib;
 } nr_rrc_du_container_t;
 
 //---NR---(completely change)---------------------

openair2/RRC/NR/rrc_gNB.c

@@ -237,11 +237,6 @@ static void init_NR_SI(gNB_RRC_INST *rrc, gNB_RrcConfigurationReq *configuration
 {
   const NR_ServingCellConfigCommon_t *scc = RC.nrmac[0]->common_channels[0].ServingCellConfigCommon;
 
-  LOG_D(RRC,"%s()\n\n\n\n",__FUNCTION__);
-  if (NODE_IS_DU(rrc->node_type) || NODE_IS_MONOLITHIC(rrc->node_type)) {
-    rrc->carrier.mib = get_new_MIB_NR(scc);
-  }
-
   if((get_softmodem_params()->sa) && ( (NODE_IS_DU(rrc->node_type) || NODE_IS_MONOLITHIC(rrc->node_type)))) {
     NR_BCCH_DL_SCH_Message_t *sib1 = get_SIB1_NR(configuration, scc);
     //xer_fprint(stdout, &asn_DEF_NR_BCCH_DL_SCH_Message, sib1);
@@ -270,7 +265,6 @@ static void init_NR_SI(gNB_RRC_INST *rrc, gNB_RrcConfigurationReq *configuration
                       rrc->configuration.pusch_AntennaPorts,
                       rrc->configuration.sib1_tda,
                       rrc->configuration.minRXTXTIME);
-    nr_mac_config_mib(RC.nrmac[rrc->module_id], rrc->carrier.mib);
   }
 
   if (get_softmodem_params()->phy_test > 0 || get_softmodem_params()->do_ra > 0) {
@@ -1931,6 +1925,18 @@ static void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req)
     return;
   }
 
+  /* do we need the MIB? for the moment, just check it is valid, then drop it */
+  NR_BCCH_BCH_Message_t *mib = NULL;
+  asn_dec_rval_t dec_rval =
+      uper_decode_complete(NULL, &asn_DEF_NR_BCCH_BCH_Message, (void **)&mib, sys_info->mib, sys_info->mib_length);
+  if (dec_rval.code != RC_OK || mib->message.present != NR_BCCH_BCH_MessageType_PR_mib
+      || mib->message.choice.messageClassExtension == NULL) {
+    LOG_E(RRC, "Failed to decode NR_BCCH_BCH_MESSAGE (%zu bits) of DU, rejecting DU\n", dec_rval.consumed);
+    rrc->mac_rrc.f1_setup_failure(&fail);
+    ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_Message, mib);
+    return;
+  }
+
   LOG_I(RRC, "Accepting DU %ld (%s), sending F1 Setup Response\n", req->gNB_DU_id, req->gNB_DU_name);
 
   // we accept the DU
@@ -1943,14 +1949,9 @@ static void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req)
   rrc->du->setup_req = malloc(sizeof(*rrc->du->setup_req));
   AssertFatal(rrc->du->setup_req != NULL, "out of memory\n");
   *rrc->du->setup_req = *req;
-
-  if (rrc->carrier.mib != NULL) {
-    LOG_E(NR_RRC, "CU MIB is already initialized: double F1 setup request?\n");
-  } else {
-    asn_dec_rval_t dec_rval =
-        uper_decode_complete(NULL, &asn_DEF_NR_BCCH_BCH_Message, (void **)&rrc->carrier.mib, sys_info->mib, sys_info->mib_length);
-    AssertFatal(dec_rval.code == RC_OK, "Failed to decode NR_BCCH_BCH_MESSAGE (%zu bits)\n", dec_rval.consumed);
-  }
+  rrc->du->mib = mib->message.choice.mib;
+  mib->message.choice.mib = NULL;
+  ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_MessageType, mib);
 
   if (rrc->carrier.sib1 != NULL) {
     LOG_E(NR_RRC, "CU SIB1 is already initiaized: double F1 setup request?\n");