+ CmdCrc(Cmd);
+ return 0;
+}
+/**
+ * @brief This method should be called when sending a new command to the pm3. In case any old
+ * responses from previous commands are stored in the buffer, a call to this method should clear them.
+ * A better method could have been to have explicit command-ACKS, so we can know which ACK goes to which
+ * operation. Right now we'll just have to live with this.
+ */
+void clearCommandBuffer()
+{
+ //This is a very simple operation
+ cmd_tail = cmd_head;
+}
+
+/**
+ * @brief storeCommand stores a USB command in a circular buffer
+ * @param UC
+ */
+void storeCommand(UsbCommand *command)
+{
+ if( ( cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail)
+ {
+ //If these two are equal, we're about to overwrite in the
+ // circular buffer.
+ PrintAndLog("WARNING: Command buffer about to overwrite command! This needs to be fixed!");
+ }
+ //Store the command at the 'head' location
+ UsbCommand* destination = &cmdBuffer[cmd_head];
+ memcpy(destination, command, sizeof(UsbCommand));
+
+ cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
+
+}
+/**
+ * @brief getCommand gets a command from an internal circular buffer.
+ * @param response location to write command
+ * @return 1 if response was returned, 0 if nothing has been received
+ */
+int getCommand(UsbCommand* response)
+{
+ //If head == tail, there's nothing to read, or if we just got initialized
+ if(cmd_head == cmd_tail) return 0;
+
+ //Pick out the next unread command
+ UsbCommand* last_unread = &cmdBuffer[cmd_tail];
+ memcpy(response, last_unread, sizeof(UsbCommand));
+ //Increment tail - this is a circular buffer, so modulo buffer size
+ cmd_tail = (cmd_tail +1 ) % CMD_BUFFER_SIZE;
+
+ return 1;
+}
+
+/**
+ * Waits for a certain response type. This method waits for a maximum of
+ * ms_timeout milliseconds for a specified response command.
+ *@brief WaitForResponseTimeout
+ * @param cmd command to wait for
+ * @param response struct to copy received command into.
+ * @param ms_timeout
+ * @return true if command was returned, otherwise false
+ */
+bool WaitForResponseTimeout(uint32_t cmd, UsbCommand* response, size_t ms_timeout) {
+
+ UsbCommand resp;
+
+ if (response == NULL)
+ response = &resp;
+
+ // Wait until the command is received
+ for ( size_t dm_seconds = 0; dm_seconds < ms_timeout/10; dm_seconds++ ) {
+
+ while( getCommand(response) ) {
+ if(response->cmd == cmd){
+ return true;
+ }
+ }
+ msleep(10); // XXX ugh
+ if (dm_seconds == 200) { // Two seconds elapsed
+ PrintAndLog("Waiting for a response from the proxmark...");
+ PrintAndLog("Don't forget to cancel its operation first by pressing on the button");
+ }
+ }
+ return false;
+}
+
+bool WaitForResponse(uint32_t cmd, UsbCommand* response) {
+ return WaitForResponseTimeout(cmd, response, -1);