add kbar parameter

radio/ETHERNET/oran/5g/oaioran.c

@@ -36,6 +36,8 @@
 #include "oaioran.h"
 #include <rte_ethdev.h>
 
+#include "oran-config.h" // for g_kbar
+
 #define USE_POLLING 1
 // Declare variable useful for the send buffer function
 volatile uint8_t first_call_set = 0;
@@ -171,13 +173,13 @@ int read_prach_data(ru_info_t *ru, int frame, int slot)
 			     if (sym_idx==0) {
 			        for (idx = 0; idx < 139*2; idx++)
 			        {
-			    	   dst[idx] = ((int16_t)ntohs(src[idx+4]));
+			    	   dst[idx] = ((int16_t)ntohs(src[idx + g_kbar]));
 			        }
 			     }
 			     else {
 			       for (idx = 0; idx < 139*2; idx++)
 			       {
-			       	   dst[idx] += ((int16_t)ntohs(src[idx+4]));
+			       	   dst[idx] += ((int16_t)ntohs(src[idx + g_kbar]));
 			       }
 			     }
                           } else if (ru_conf->compMeth_PRACH == XRAN_COMPMETHOD_BLKFLOAT) {
@@ -202,9 +204,9 @@ int read_prach_data(ru_info_t *ru, int frame, int slot)
                                  xranlib_decompress_avx512(&bfp_decom_req, &bfp_decom_rsp);
                              // note: this is hardwired for 139 point PRACH sequence, kbar=2
                              if (sym_idx == 0)  // 
-	                        for (idx = 0; idx < (139*2); idx++) dst[idx]=local_dst[idx+4];
+	                        for (idx = 0; idx < (139*2); idx++) dst[idx]=local_dst[idx + g_kbar];
 			         else
-                                for (idx = 0; idx < (139*2); idx++) dst[idx]+=(local_dst[idx+4]);
+                                for (idx = 0; idx < (139*2); idx++) dst[idx]+=(local_dst[idx + g_kbar]);
 			  } // COMPMETHOD_BLKFLOAT
 		} //aa
 	  }// symb_indx

radio/ETHERNET/oran/5g/oran-config.c

@@ -637,6 +637,13 @@ static enum xran_cp_filterindex get_prach_filterindex_fr1(duplex_mode_t mode, in
   return XRAN_FILTERINDEX_STANDARD;
 }
 
+// PRACH guard interval. Raymond: "[it] is not in the configuration, (i.e. it
+// is deterministic depending on others). LiteON must hard-code this in the
+// O-RU itself, benetel doesn't (as O-RAN specifies). So we will need to tell
+// the driver what the case is and provide"
+// this is a hack
+int g_kbar;
+
 static bool set_fh_prach_config(const openair0_config_t* oai0, const paramdef_t *prachp, int nprach, struct xran_prach_config *prach_config)
 {
   const split7_config_t *s7cfg = &oai0->split7;
@@ -663,6 +670,8 @@ static bool set_fh_prach_config(const openair0_config_t* oai0, const paramdef_t
   prach_config->eAxC_offset = *gpd(prachp, nprach, ORAN_PRACH_CONFIG_EAXC_OFFSET)->uptr;
   DevAssert(prach_config->eAxC_offset == 4);
 
+  g_kbar = *gpd(prachp, nprach, ORAN_PRACH_CONFIG_KBAR)->uptr;
+
   return true;
 }
 

radio/ETHERNET/oran/5g/oran-config.h

@@ -34,4 +34,7 @@ bool set_fh_init(struct xran_fh_init *fh_init);
 struct openair0_config;
 bool set_fh_config(int ru_idx, const struct openair0_config *oai0_cfg, struct xran_fh_config *fh_config);
 
+// hack to workaround LiteOn limitation
+extern int g_kbar;
+
 #endif /* ORAN_CONFIG_H */

radio/ETHERNET/oran/5g/oran-params.h

@@ -105,10 +105,12 @@
 #define CONFIG_STRING_ORAN_PRACH "prach_config"
 
 #define ORAN_PRACH_CONFIG_EAXC_OFFSET "eAxC_offset"
+#define ORAN_PRACH_CONFIG_KBAR "kbar"
 
 // clang-format off
 #define ORAN_PRACH_DESC {\
   {ORAN_PRACH_CONFIG_EAXC_OFFSET, "RU's eAxC offset for PRACH\n", PARAMFLAG_MANDATORY, .u8ptr=NULL, .defuintval=0, TYPE_UINT8, 0}, \
+  {ORAN_PRACH_CONFIG_KBAR,        "PRACH guard interval\n",       0,                   .uptr=NULL,  .defuintval=4, TYPE_UINT,  0}, \
 }
 // clang-format on
 

targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf

@@ -297,6 +297,7 @@ fhi_72 = {
     };
     prach_config = {
       eAxC_offset = 4;
+      kbar = 0;
     };
   });
 };