[Legacy] maintain decoder compatibility with Air V6

software/firmware/source/SoftRF/src/protocol/radio/Legacy.cpp

@@ -152,11 +152,9 @@ void make_key(uint32_t key[4], uint32_t timestamp, uint32_t address) {
     }
 }
 
-#if USE_AIR_V6
-
-bool legacy_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
+static bool legacy_v6_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
 
-    legacy_packet_t *pkt = (legacy_packet_t *) legacy_pkt;
+    legacy_v6_packet_t *pkt = (legacy_v6_packet_t *) legacy_pkt;
 
     float ref_lat = this_aircraft->latitude;
     float ref_lon = this_aircraft->longitude;
@@ -170,7 +168,7 @@ bool legacy_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
     make_key(key, timestamp, (pkt->addr << 8) & 0xffffff);
     btea((uint32_t *) pkt + 1, -5, key);
 
-    for (ndx = 0; ndx < sizeof (legacy_packet_t); ndx++) {
+    for (ndx = 0; ndx < sizeof (legacy_v6_packet_t); ndx++) {
       pkt_parity += parity(*(((unsigned char *) pkt) + ndx));
     }
     if (pkt_parity % 2) {
@@ -231,9 +229,16 @@ bool legacy_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
     return true;
 }
 
+#if USE_AIR_V6
+
+bool legacy_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
+
+    return legacy_v6_decode(legacy_pkt, this_aircraft, fop);
+}
+
 size_t legacy_encode(void *legacy_pkt, ufo_t *this_aircraft) {
 
-    legacy_packet_t *pkt = (legacy_packet_t *) legacy_pkt;
+    legacy_v6_packet_t *pkt = (legacy_v6_packet_t *) legacy_pkt;
 
     int ndx;
     uint8_t pkt_parity=0;
@@ -303,13 +308,13 @@ size_t legacy_encode(void *legacy_pkt, ufo_t *this_aircraft) {
     pkt->ns[0] = ns; pkt->ns[1] = ns; pkt->ns[2] = ns; pkt->ns[3] = ns;
     pkt->ew[0] = ew; pkt->ew[1] = ew; pkt->ew[2] = ew; pkt->ew[3] = ew;
 
-    pkt->_unk0 = 0;
+    pkt->type  = 0;
     pkt->_unk1 = 0;
     pkt->_unk2 = 0;
     pkt->_unk3 = 0;
 //    pkt->_unk4 = 0;
 
-    for (ndx = 0; ndx < sizeof (legacy_packet_t); ndx++) {
+    for (ndx = 0; ndx < sizeof (legacy_v6_packet_t); ndx++) {
       pkt_parity += parity(*(((unsigned char *) pkt) + ndx));
     }
 
@@ -325,7 +330,7 @@ size_t legacy_encode(void *legacy_pkt, ufo_t *this_aircraft) {
 #endif
     btea((uint32_t *) pkt + 1, 5, key);
 
-    return (sizeof(legacy_packet_t));
+    return (sizeof(legacy_v6_packet_t));
 }
 
 #elif USE_AIR_V7
@@ -336,7 +341,11 @@ size_t legacy_encode(void *legacy_pkt, ufo_t *this_aircraft) {
 
 bool legacy_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
 
-    legacy_packet_t *pkt = (legacy_packet_t *) legacy_pkt;
+    legacy_v7_packet_t *pkt = (legacy_v7_packet_t *) legacy_pkt;
+
+    if (pkt->type == 0) { /* Air V6 position */
+      return legacy_v6_decode(legacy_pkt, this_aircraft, fop);
+    }
 
     /* TODO */
 
@@ -345,11 +354,11 @@ bool legacy_decode(void *legacy_pkt, ufo_t *this_aircraft, ufo_t *fop) {
 
 size_t legacy_encode(void *legacy_pkt, ufo_t *this_aircraft) {
 
-    legacy_packet_t *pkt = (legacy_packet_t *) legacy_pkt;
+    legacy_v7_packet_t *pkt = (legacy_v7_packet_t *) legacy_pkt;
 
     /* TODO */
 
-    return (sizeof(legacy_packet_t));
+    return (sizeof(legacy_v7_packet_t));
 }
 
 #else

software/firmware/source/SoftRF/src/protocol/radio/Legacy.h

@@ -130,15 +130,12 @@ enum
 	TX_STATUS_ON
 };
 
-#if USE_AIR_V6
-
 typedef struct {
     /********************/
     unsigned int addr:24;
-    unsigned int _unk0:4;
+    unsigned int type:4;
     unsigned int addr_type:3;
     unsigned int _unk1:1;
-    // unsigned int magic:8;
     /********************/
     int vs:10;
     unsigned int _unk2:2;
@@ -159,23 +156,27 @@ typedef struct {
     int8_t ns[4];
     int8_t ew[4];
     /********************/
-} __attribute__((packed)) legacy_packet_t;
+} __attribute__((packed)) legacy_v6_packet_t;
 
-#elif USE_AIR_V7
 /*
  * Volunteer contributors are welcome:
  * https://pastebin.com/YB1ppAbt
  */
 
 typedef struct {
 
-    /* TODO */
+    /********************/
+    unsigned int addr:24;
+    unsigned int type:4;
+    unsigned int addr_type:3;
+    unsigned int _unk1:1;
+    /********************/
+
+    /* TBD */
+    uint32_t stub[5];
 
-} __attribute__((packed)) legacy_packet_t;
+} __attribute__((packed)) legacy_v7_packet_t;
 
-#else
-#error "Unknown AIR protocol version"
-#endif /* USE_AIR_Vx */
 
 bool   legacy_decode(void *, ufo_t *, ufo_t *);
 size_t legacy_encode(void *, ufo_t *);