efinix: Add header parsing and flash programming validation

Parse bitstream header to extract Mode, Width and Device fields.
Add validation for flash programming:
- Check device matches --fpga-part parameter
- Reject passive mode (only active mode supported for flash)

This prevents flashing incorrect bitstreams that would fail to boot.

src/efinixHexParser.cpp

@@ -17,9 +17,55 @@ EfinixHexParser::EfinixHexParser(const string &filename):
 		false)
 {}
 
+int EfinixHexParser::parseHeader()
+{
+	string buffer;
+	istringstream lineStream(_raw_data);
+	int bytesRead = 0;
+	string headerText;
+	bool foundPaddedBits = false;
+	
+	while (std::getline(lineStream, buffer, '\n')) {
+		bytesRead += buffer.size() + 1;
+		
+		if (buffer != "0A") {
+			try {
+				uint8_t byte = std::stol(buffer, nullptr, 16);
+				headerText += (char)byte;
+			} catch (...) {
+			}
+		} else {
+			headerText += '\n';
+			if (foundPaddedBits)
+				break;
+		}
+		
+		if (headerText.find("PADDED_BITS") != string::npos)
+			foundPaddedBits = true;
+	}
+	
+	size_t pos;
+	if ((pos = headerText.find("Mode: ")) != string::npos) {
+		size_t end = headerText.find('\n', pos);
+		_hdr["mode"] = headerText.substr(pos + 6, end - pos - 6);
+	}
+	if ((pos = headerText.find("Width: ")) != string::npos) {
+		size_t end = headerText.find('\n', pos);
+		_hdr["width"] = headerText.substr(pos + 7, end - pos - 7);
+	}
+	if ((pos = headerText.find("Device: ")) != string::npos) {
+		size_t end = headerText.find('\n', pos);
+		_hdr["device"] = headerText.substr(pos + 8, end - pos - 8);
+	}
+	
+	return bytesRead;
+}
+
 int EfinixHexParser::parse()
 {
 	string buffer;
+	parseHeader();
+	
 	istringstream lineStream(_raw_data);
 
 	while (std::getline(lineStream, buffer, '\n')) {