Add edit capability to the hex editor

firmware/apps/hex.c

@@ -6,14 +6,11 @@
   easy to fork for other purposes.
 */
 
-
-
 //MSP430 functions for the SFRIE.
 #include <msp430.h>
 
 //Include all standard GoodWatch functions.
 #include "api.h"
-
 #include "hex.h"
 
 //! Returns 1 if a given address is legal.
@@ -26,6 +23,19 @@ static int hex_islegal(unsigned int adr){
 	   );
 }
 
+static int hex_can_edit(unsigned int adr) {
+  return !(
+    (adr >= 0x1000 && adr <= 0x17ff) || // Bootloader
+
+    // Unknown peripheral; don't know how to unlock this region.
+    (adr >= 0x1b00 && adr < 0x1c00) ||
+
+    (adr >= 0x8000) || // Flash Memory
+    (adr >= 0x1800 && adr < 0x19ff) // Info flash
+  );
+}
+
+
 //! Entry to the hex editor app.
 void hex_init(){
   /* This function is called whenever the app is selected by the Mode
@@ -38,12 +48,20 @@ void hex_init(){
   SFRIE1&=~(VMAIE|ACCVIE);
   //Disable BSL protections, so we can read it without trouble.
   SYSBSLC=3;
+
   //Force drawing the first frame.
   hex_draw(1);
 
   return;
 }
 
+//! Address of the hex editor.
+static int adr=0x8000; //Beginning of Flash.
+
+//! If non-zero, we are editing the memory; value is the digit being edited.
+static int editing = 0;
+
+static unsigned int new_val = 0;
 
 //! Exit from the hex editor app.
 int hex_exit(){
@@ -52,52 +70,89 @@ int hex_exit(){
      own app is using the button, so we return 0 to indicate that the
      task manager is welcome to switch to the next app.
    */
+  if (editing) {
+    editing++;
+    return 1;
+  }
   return 0;
 }
 
-//! Address of the hex editor.
-static int adr=0x8000; //Beginning of Flash.
 
 //! A button has been pressed for the hex editor.
 int hex_keypress(char ch){
   //Handle the input that we received by an event.
-  switch(ch){
-  case '4':// Hold 4 to disassemble the curent instruction.
-    lcd_zero();
-    asm_dis(adr,
-	      ((unsigned int*)adr)[0],
-	      ((unsigned int*)adr)[1],
-	      ((unsigned int*)adr)[2]);
-    asm_show();
-    return 0;  //We'll redraw when the button is released.
-
-    /* The top button on each column increases that nybble of the address.
-       The bottom button reduces it.
-    */
-  case '7':
-    adr+=0x1000;
-    break;
-  case '0':
-    adr-=0x1000;
-    break;
-  case '8':
-    adr+=0x0100;
-    break;
-  case '.':
-    adr-=0x0100;
-    break;
-  case '9':
-    adr+=0x0010;
-    break;
-  case '=':
-    adr-=0x0010;
-    break;
-  case '/':
-    adr+=2;
-    break;
-  case '+':
-    adr-=2;
-    break;
+  if (editing) {
+    // Convert keypress to a nibble
+    if (ch == 0) {
+      return 0;
+    }
+    // A non-numeric key has been pressed
+    char inputdigit;
+    switch (ch) {
+      case '/':
+        inputdigit = 0x0A;
+      break;
+      case '*':
+        inputdigit = 0x0B;
+      break;
+      case '-':
+        inputdigit = 0x0C;
+      break;
+      case '+':
+        inputdigit = 0x0D;
+      break;
+      case '=':
+        inputdigit = 0x0E;
+      break;
+      case '.':
+        inputdigit = 0x0F;
+      break;
+      default: // One of the (0-9) digits was pressed
+        inputdigit = ch & 0x0F;
+    }
+
+    char shift = ((4 - editing) * 4);
+    new_val = (new_val & ~(0xF << shift)) | (inputdigit << shift);
+    editing++;
+  } else {
+    switch(ch){
+    case '4':// Hold 4 to disassemble the curent instruction.
+      lcd_zero();
+      asm_dis(adr,
+          ((unsigned int*)adr)[0],
+          ((unsigned int*)adr)[1],
+          ((unsigned int*)adr)[2]);
+      asm_show();
+      return 0;  //We'll redraw when the button is released.
+
+      /* The top button on each column increases that nybble of the address.
+        The bottom button reduces it.
+      */
+    case '7':
+      adr+=0x1000;
+      break;
+    case '0':
+      adr-=0x1000;
+      break;
+    case '8':
+      adr+=0x0100;
+      break;
+    case '.':
+      adr-=0x0100;
+      break;
+    case '9':
+      adr+=0x0010;
+      break;
+    case '=':
+      adr-=0x0010;
+      break;
+    case '/':
+      adr+=2;
+      break;
+    case '+':
+      adr-=2;
+      break;
+    }
   }
 
   //Force a redraw out-of-frame.
@@ -114,8 +169,50 @@ void hex_draw(int forced){
      Our screen is double-buffered, so the user won't notice it all
      being drawn.
    */
-
-  if(forced){
+  static int flicker = 0;
+
+  // The sidebutton needs to be polled for a change
+  if (sidebutton_set()) {
+    editing = !editing;
+    if (editing) {
+      if(!hex_can_edit(adr)){
+        // do not allow editing of memory regions that do not support editing
+        editing = 0;
+      } else {
+        // Initialize the new value to the value currently in memory
+        new_val = ((unsigned int*)adr)[0];
+      }
+    } else {
+      forced = 1; // The screen needs to be redrawn. Cancelling editing using
+      // the set button will not trigger a redraw, so we do it manually.
+    }
+  }
+
+  // editing mode draws every cycle to flash the nibble currently being input
+  if (editing) {
+    // Editing mode needs to handle input from the mode button and the keypad
+    // because of this, any updates that can be triggered by the mode button
+    // and the keypad are handled here. 
+    lcd_zero();
+    lcd_hex(
+      (((unsigned long)adr) << 16) // Address
+      | new_val //data
+    );
+    setperiod(4, 1);
+
+    if (editing <= 4) {
+      flicker = !flicker;
+      if (flicker) {
+        lcd_cleardigit(4 - editing);
+      }
+    } else {
+      // Editing is > 4, so one word of data has been input. Write the value
+      // to ram and exit editing mode
+      ((unsigned int*)adr)[0] = new_val;
+      editing = 0;
+      flicker = 0; // Probably not necessary, but nice to reset state
+    }
+  } else if(forced) {
     //And finally we draw the result to the screen.
     lcd_zero();
 
@@ -126,21 +223,22 @@ void hex_draw(int forced){
     */
     if(!hex_islegal(adr)){
       lcd_hex(
-	      (((unsigned long)adr)<<16) // Address
-	      );
+              (((unsigned long)adr)<<16) // Address
+              );
       lcd_cleardigit(3);
       lcd_cleardigit(2);
       lcd_cleardigit(1);
       lcd_cleardigit(0);
       return;
     }else{
       /* Now that the range is legal and the value known, let's fetch the
-	 value and display it.
+         value and display it.
       */
       lcd_hex(
-	      (((unsigned long)adr)<<16) // Address
-	      | ((unsigned int*)adr)[0] //data
-	      );
+              (((unsigned long)adr)<<16) // Address
+              | ((unsigned int*)adr)[0] //data
+              );
     }
   }
+
 }