Versión funcional

main.cpp

@@ -7,10 +7,16 @@
 
 using namespace std;
 
-ifstream inputFile;
 string filePath = "";
 vector<unsigned char> buffer;
 
+int desp = 0x2000;
+int numBytes = 0x2000;
+int firstByte = desp + 0x200;
+int lastByte = desp + numBytes - 1;
+int checksum1 = desp + 0x270;
+int checksum2 = desp + 0x271;
+
 void checkParameters(int argc, char *argv[])
 {
     if (argc != 2)
@@ -24,16 +30,34 @@ void checkParameters(int argc, char *argv[])
 
 void loadFile(string s)
 {
-    inputFile.open(s, ios::binary);
-    if (!inputFile.good())
+    ifstream inputFile(s, ios::binary);
+    if (inputFile.good())
+        buffer.assign(istreambuf_iterator<char>(inputFile), {});
+    else
     {
         cout << "No se puede abrir el archivo: " << s << endl;
         exit(EXIT_FAILURE);
     }
+    inputFile.close();
+}
 
-    // Copia el stream al buffer
-    vector<unsigned char> temp(std::istreambuf_iterator<char>(inputFile), {});
-    buffer = temp;
+void saveFile(string s)
+{
+    ofstream outputFile(s, ios::binary);
+    if (outputFile.good())
+    {
+        for (auto i : buffer)
+        {
+            outputFile << i;
+        }
+        cout << "Fichero guardado: " << s << endl;
+    }
+    else
+    {
+        cout << "No se puede abrir el archivo: " << s << endl;
+        exit(EXIT_FAILURE);
+    }
+    outputFile.close();
 }
 
 void printBuffer()
@@ -48,11 +72,31 @@ void printBuffer()
     }
 }
 
+int calcChecksum()
+{
+    int sum = 0;
+    for (int i = firstByte; i <= lastByte; i++)
+    {
+        if (i != checksum1 and i != checksum2)
+            sum += static_cast<unsigned>(buffer.at(i));
+    }
+    sum += 3328; // Corrige el checksum
+    buffer.at(checksum1) = sum % 256;
+    buffer.at(checksum2) = (sum >> 8) % 256;
+    return sum;
+}
+
 int main(int argc, char *argv[])
 {
     checkParameters(argc, argv);
     loadFile(filePath);
-    printBuffer();
-    cout << "Fin del programa" << endl;
+    int sum = calcChecksum();
+    saveFile(filePath);
+
+    cout << hex;
+    cout << "0x" << checksum1 << ": 0x" << static_cast<unsigned>(buffer.at(checksum1)) << endl;
+    cout << "0x" << checksum2 << ": 0x" << static_cast<unsigned>(buffer.at(checksum2)) << endl;
+    cout << "checksum (0x" << firstByte << " .. 0x" << lastByte << "): 0x" << sum << endl;
+
     return 0;
 }