From c3f849d1433d7a51938d05f19ed5b5dd1478cb0e Mon Sep 17 00:00:00 2001
From: D R <dan@maybefishing.net>
Date: Wed, 21 Sep 2022 15:35:51 +0100
Subject: [PATCH] Write buffer and other write function bugs fixed!

Corrected some bugs in the write buffer and other parts of the write functions, I've now written 5120 bytes of the Z80 bootldr.com file to flash and verified it's correct. See also the C# application which has also changed, without which you'll get wrong data!!
---
 .../sketch_sst39sf040_flash.ino               | 33 +++++++++++++++----
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/sketch_sst39sf040_flash/sketch_sst39sf040_flash.ino b/sketch_sst39sf040_flash/sketch_sst39sf040_flash.ino
index aec6d33..c8b89c8 100644
--- a/sketch_sst39sf040_flash/sketch_sst39sf040_flash.ino
+++ b/sketch_sst39sf040_flash/sketch_sst39sf040_flash.ino
@@ -41,6 +41,7 @@ boolean commandValid = 0;
 long writeAddressCounter = 0;
 long bytesWrittenCounter = 0;
 boolean StreamMode = 0;           //Set to 1 when the serial data isn't formatted and just a stream of 2048 bytes
+long totalSize = 0;
 long bytesToWrite = 0;
 
 void recvWithStartEndMarkers() 
@@ -50,25 +51,39 @@ void recvWithStartEndMarkers()
     char startMarker = '<';
     char endMarker = '>';
     char rc;
-    byte bc[256];      //Our byte buffer which needs to be bigger, say 256 bytes
+    byte bc[50];      //Our byte buffer which needs to be bigger, say 256 bytes
     //We need to check StreamMode == 1 and then ignore the start and end markers
  // if (Serial.available() > 0) {
     while (Serial.available() > 0 && newData == false) {
         if(StreamMode == 0)
           rc = Serial.read();
         else
-          Serial.readBytes(bc, bytesToWrite);
+          Serial.readBytes(bc, bytesToWrite);    //read block size amount of bytes to write
 
         if(StreamMode == 1)
         {
             //Write each byte in the bc array using  bytesToWrite as the max count
             for(int c = 0; c < bytesToWrite; c++)
             {
+              if(writeAddressCounter >= totalSize)
+              {
+                StreamMode = 0;
+                break;
+              }
               programData(bc[c], writeAddressCounter);
               writeAddressCounter++;
             }
-            Serial.println("Flash Written Successfully.");
-            StreamMode = 0;
+            //This part is wrong, we need to continue to grab serial data and write it until we hit writeAddressCounter == bytesToWrite
+            if(writeAddressCounter >= totalSize)
+            {
+              Serial.println("Flash Written Successfully.");
+              StreamMode = 0;
+            } //Else we carry on with getting data and writing it
+            else
+            {
+              Serial.print("OK");   //Signal sender to send next block
+              Serial.println(writeAddressCounter);
+            }
             
         } else
         {
@@ -158,7 +173,7 @@ void showNewData()
 
       //parse the second paramter which is the byte value, or the end address in the case of a read (R) or dump (D)
       strtokIndx = strtok(NULL, ",");
-      if(messageFromPC[0] == 'R' || messageFromPC[0] == 'D' || messageFromPC[0] == 'Y')
+      if(messageFromPC[0] == 'R' || messageFromPC[0] == 'D' || messageFromPC[0] == 'Y' || messageFromPC[0] == 'Z' || messageFromPC[0] == 'X')
         endAddressFromPC = atol(strtokIndx);
       else
         byteFromPC = atoi(strtokIndx);
@@ -310,11 +325,15 @@ void showNewData()
         commandValid = 1;
       }
 
-      //Set the bytes to write counter
+      //Set the bytes to write counter (a block of bytes not the whole lot!)
       if(messageFromPC[0] == 'Z')
       {
         bytesToWrite = addressFromPC;
-        writeAddressCounter = 0;
+        totalSize = endAddressFromPC;
+        Serial.print(bytesToWrite);
+        Serial.print(" block size with a total of: ");
+        Serial.print(totalSize);
+        Serial.println(" bytes");
         commandValid = 1;
       }