make hf search robust to various HF configurations

armsrc/appmain.c

@@ -1090,6 +1090,12 @@ static void PacketReceived(PacketCommandNG *packet) {
         }
 #endif
 
+// always available
+        case CMD_HF_DROPFIELD: {
+            hf_field_off();
+            break;
+        }
+
 #ifdef WITH_ISO14443a
         case CMD_HF_ISO14443A_SNIFF: {
             SniffIso14443a(packet->data.asBytes[0]);

armsrc/iso14443a.c

@@ -14,7 +14,7 @@
 #define MAX_ISO14A_TIMEOUT 524288
 static uint32_t iso14a_timeout;
 // if iso14443a not active - transmit/receive dont try to execute
-static bool iso14443a_active = false;
+static bool hf_field_active = false;
 
 uint8_t colpos = 0;
 int rsamples = 0;
@@ -1629,7 +1629,7 @@ void PrepareDelayedTransfer(uint16_t delay) {
 //-------------------------------------------------------------------------------------
 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) {
 
-    if (!iso14443a_active)
+    if (!hf_field_active)
         return;
 
     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
@@ -2014,7 +2014,7 @@ bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_Start
 //-----------------------------------------------------------------------------
 bool GetIso14443aAnswerFromTag_Thinfilm(uint8_t *receivedResponse,  uint8_t *received_len) {
 
-    if (!iso14443a_active)
+    if (!hf_field_active)
         return false;
 
     // Set FPGA mode to "reader listen mode", no modulation (listen
@@ -2063,7 +2063,7 @@ bool GetIso14443aAnswerFromTag_Thinfilm(uint8_t *receivedResponse,  uint8_t *rec
 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) {
     uint32_t c = 0;
 
-    if (!iso14443a_active)
+    if (!hf_field_active)
         return false;
 
     // Set FPGA mode to "reader listen mode", no modulation (listen
@@ -2504,14 +2504,14 @@ void iso14443a_setup(uint8_t fpga_minor_mode) {
     NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
     iso14a_set_timeout(1060); // 106 * 10ms default
 
-    iso14443a_active = true;
+    hf_field_active = true;
 }
 
 
-void iso14443a_off(void) {
+void hf_field_off(void) {
     FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
     LEDsoff();
-    iso14443a_active = false;
+    hf_field_active = false;
 }
 
 /* Peter Fillmore 2015
@@ -2716,7 +2716,7 @@ void ReaderIso14443a(PacketCommandNG *c) {
         return;
 
 OUT:
-    iso14443a_off();
+    hf_field_off();
     set_tracing(false);
 }
 
@@ -3011,7 +3011,7 @@ void ReaderMifare(bool first_try, uint8_t block, uint8_t keytype) {
 
     reply_mix(CMD_ACK, isOK, 0, 0, buf, sizeof(buf));
 
-    iso14443a_off();
+    hf_field_off();
     set_tracing(false);
 }
 
@@ -3250,6 +3250,6 @@ void DetectNACKbug(void) {
 
     //reply_mix(CMD_ACK, isOK, num_nacks, i, 0, 0);
     BigBuf_free();
-    iso14443a_off();
+    hf_field_off();
     set_tracing(false);
 }

armsrc/iso14443a.h

@@ -132,7 +132,7 @@ int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, bool send_chaining, void *data, u
 int iso14443a_select_card(uint8_t *uid_ptr, iso14a_card_select_t *p_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades, bool no_rats);
 int iso14443a_fast_select_card(uint8_t *uid_ptr, uint8_t num_cascades);
 void iso14a_set_trigger(bool enable);
-void iso14443a_off(void);
+void hf_field_off(void);
 
 int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen);
 int EmSend4bit(uint8_t resp);

armsrc/thinfilm.c

@@ -32,7 +32,7 @@ void ReadThinFilm(void) {
     bool status = GetIso14443aAnswerFromTag_Thinfilm(buf, &len);
     reply_ng(CMD_HF_THINFILM_READ, status ? PM3_SUCCESS : PM3_ENODATA, buf, len);
 
-    iso14443a_off();
+    hf_field_off();
     set_tracing(false);
 }