adding & utilizing hex reader

js/hex_reader.js

@@ -0,0 +1,52 @@
+// input = string
+// result = if hex file is valid, result contains hex array of raw data (pure binary representation of firmware)
+//          if hex file wasn't valid (crc check failed on any of the lines), resul will be false
+function read_hex_file(data) {
+    data = data.split("\n");
+    
+    // check if there is an empty line in the end of hex file, if there is, remove it
+    if (data[data.length - 1] == "") {
+        data.pop();
+    }
+    
+    var raw_hex = new Array();
+    var bytes_total = 0; // just for info / debug purposes
+    var hexfile_valid = true; // if any of the crc checks failed, this variable flips to false
+    for (var i = 0; i < data.length; i++) {
+        var byte_count = parseInt(data[i].substr(1, 2), 16) * 2; // each byte is represnted by two chars (* 2 to get the hex representation)
+        var address = data[i].substr(3, 4);
+        var record_type = parseInt(data[i].substr(7, 2), 16); // also converting from hex to decimal
+        var content = data[i].substr(9, byte_count);
+        var checksum = parseInt(data[i].substr(9 + byte_count, 2), 16); // also converting from hex to decimal (this is a 2's complement value)
+       
+        if (byte_count > 0) {
+            var crc = (byte_count / 2) + parseInt(address.substr(0, 2), 16) + parseInt(address.substr(2, 2), 16) + record_type;
+            for (var needle = 0; needle < byte_count; needle += 2) {
+                var num = parseInt(content.substr(needle, 2), 16); // get one byte in hex and convert it to decimal
+                raw_hex.push(num);
+                
+                crc += num;
+                bytes_total++;
+            }
+            
+            // change crc to 2's complement (same as checksum)
+            crc = ~crc + 1;
+            crc &= 0xFF;
+            
+            // verify 
+            if (crc != checksum) {
+                hexfile_valid = false;
+            }
+        }
+    }
+    
+    if (hexfile_valid) {
+        console.log('HEX file parsed: ' + bytes_total + ' bytes');
+        
+        return raw_hex;
+    } else {
+        console.log('HEX file parsed, CRC check failed: ' + bytes_total + ' bytes');
+        
+        return false;
+    }
+}

main.html

@@ -16,6 +16,7 @@
         <script type="text/javascript" src="./js/msp.js"></script>
         <script type="text/javascript" src="./main.js"></script>
         <script type="text/javascript" src="./js/backup_restore.js"></script>
+        <script type="text/javascript" src="./js/hex_reader.js"></script>
 
         <!-- Various tabs are divided into separate files (for clarity) --> 
         <script type="text/javascript" src="./tabs/default.js"></script>

tabs/firmware_flasher.js

@@ -2,7 +2,8 @@ function tab_initialize_firmware_flasher() {
     ga_tracker.sendAppView('Firmware Flasher');
     GUI.active_tab = 'firmware_flasher';
     
-    var intel_hex = false;
+    var intel_hex = false; // standard intel hex in string format
+    var raw_hex = false; // parsed raw hex in array format
     
     $('#content').load("./tabs/firmware_flasher.html", function() {
         // UI Hooks
@@ -28,6 +29,7 @@ function tab_initialize_firmware_flasher() {
                             console.log('File loaded');
                             
                             intel_hex = e.target.result;
+                            raw_hex = read_hex_file(intel_hex);
                         };
 
                         reader.readAsText(file);