X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/ab7a8ea16420243ad132b21f968ea15a3b14fa61..e772353f72729f0dfc80a4d93c3a7bd2ac5ea775:/client/cmdmain.c

diff --git a/client/cmdmain.c b/client/cmdmain.c
index 85a0e0ca..64e0c1b4 100644
--- a/client/cmdmain.c
+++ b/client/cmdmain.c
@@ -25,6 +25,7 @@
 #include "cmdmain.h"
 #include "util.h"
 
+
 unsigned int current_command = CMD_UNKNOWN;
 //unsigned int received_command = CMD_UNKNOWN;
 //UsbCommand current_response;
@@ -39,7 +40,7 @@ static UsbCommand cmdBuffer[CMD_BUFFER_SIZE];
 //Points to the next empty position to write to
 static int cmd_head;//Starts as 0
 //Points to the position of the last unread command
-static int cmd_tail = -1;//Starts as -1
+static int cmd_tail;//Starts as 0
 
 static command_t CommandTable[] = 
 {
@@ -64,6 +65,8 @@ int CmdQuit(const char *Cmd)
   exit(0);
   return 0;
 }
+int getCommand(UsbCommand* response);
+void storeCommand(UsbCommand *command);
 /**
  * Waits for a certain response type. This method waits for a maximum of
  * ms_timeout milliseconds for a specified response command.
@@ -83,9 +86,13 @@ bool WaitForResponseTimeout(uint32_t cmd, UsbCommand* response, size_t ms_timeou
   // Wait until the command is received
   for(size_t dm_seconds=0; dm_seconds < ms_timeout/10; dm_seconds++) {
 
-      if(getCommand(response) && response->cmd == cmd){
+      while(getCommand(response))
+      {
+          if(response->cmd == cmd){
           //We got what we expected
           return true;
+          }
+
       }
         msleep(10); // XXX ugh
         if (dm_seconds == 200) { // Two seconds elapsed
@@ -205,13 +212,26 @@ void UsbCommandReceived(UsbCommand *UC)
   storeCommand(UC);
 
 }
+
+/**
+ * @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 == cmd_tail)
+    if( ( cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail)
     {
         //If these two are equal, we're about to overwrite in the
         // circular buffer.
@@ -221,14 +241,7 @@ void storeCommand(UsbCommand *command)
     UsbCommand* destination = &cmdBuffer[cmd_head];
     memcpy(destination, command, sizeof(UsbCommand));
 
-    //Also, if cmd_tail is still -1 because the buffer was
-    // previously empty, set it to head
-    if(cmd_tail < 0) {
-        cmd_tail = cmd_head;
-    }
-
-    cmd_head++; //increment head
-    cmd_head %= CMD_BUFFER_SIZE;//wrap around
+    cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
 
 }
 /**
@@ -239,7 +252,7 @@ void storeCommand(UsbCommand *command)
 int getCommand(UsbCommand* response)
 {
     //If head == tail, there's nothing to read, or if we just got initialized
-    if(cmd_head == cmd_tail || cmd_tail == -1){
+    if(cmd_head == cmd_tail){
         return 0;
     }
     //Pick out the next unread command
@@ -247,12 +260,6 @@ int getCommand(UsbCommand* response)
     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;
-    //In order to detect when the buffer overwrites itself, we set the
-    // tail to -1 whenever it 'catches up' with head : this means the buffer is empty.
-    // Otherwise, head==tail could mean both: either empty or full.
-    if(cmd_tail == cmd_head){
-        cmd_tail = -1 ;
-    }
 
     return 1;