Linux: Support keys in config file (#1093)

- Signing and encryption keys are set through the configuration file.
- SoftEeprom update.

drivers/Linux/SoftEeprom.cpp

@@ -60,9 +60,6 @@ int SoftEeprom::init(const char *fileName, size_t length)
 
 	_length = length;
 	_values = new uint8_t[_length];
-	for (size_t i = 0; i < _length; ++i) {
-		_values[i] = 0xFF;
-	}
 
 	if (stat(_fileName, &fileInfo) != 0) {
 		//File does not exist.  Create it.
@@ -72,11 +69,16 @@ int SoftEeprom::init(const char *fileName, size_t length)
 			logError("Unable to create config file %s.\n", _fileName);
 			return -1;
 		}
+		// Fill the eeprom with 1s
+		for (size_t i = 0; i < _length; ++i) {
+			_values[i] = 0xFF;
+		}
 		myFile.write((const char*)_values, _length);
 		myFile.close();
 	} else if (fileInfo.st_size < 0 || (size_t)fileInfo.st_size != _length) {
 		logError("EEPROM file %s is not the correct size of %zu.  Please remove the file and a new one will be created.\n",
 		         _fileName, _length);
+		destroy();
 		return -1;
 	} else {
 		//Read config into local memory.
@@ -100,27 +102,19 @@ void SoftEeprom::destroy()
 	if (_fileName) {
 		free(_fileName);
 	}
+	_length = 0;
 }
 
 void SoftEeprom::readBlock(void* buf, void* addr, size_t length)
 {
-	static bool config_to_mem = false;
 	unsigned long int offs = reinterpret_cast<unsigned long int>(addr);
 
-	if (!config_to_mem && length) {
-		//Read config into local memory.
-		std::ifstream myFile(_fileName, std::ios::in | std::ios::binary);
-		if (!myFile) {
-			logError("Unable to open config to file %s for reading.\n", _fileName);
-			exit(1);
-		}
-		myFile.read((char*)_values, _length);
-		myFile.close();
-
-		config_to_mem = true;
+	if (!length) {
+		logError("EEPROM being read without being initialized!\n");
+		return;
 	}
 
-	if (length && offs + length <= _length) {
+	if (offs + length <= _length) {
 		memcpy(buf, _values+offs, length);
 	}
 }
@@ -129,7 +123,16 @@ void SoftEeprom::writeBlock(void* buf, void* addr, size_t length)
 {
 	unsigned long int offs = reinterpret_cast<unsigned long int>(addr);
 
-	if (length && offs + length <= _length) {
+	if (!length) {
+		logError("EEPROM being written without being initialized!\n");
+		return;
+	}
+
+	if (offs + length <= _length) {
+		if (memcmp(_values+offs, buf, length) == 0) {
+			return;
+		}
+
 		memcpy(_values+offs, buf, length);
 
 		std::ofstream myFile(_fileName, std::ios::out | std::ios::in | std::ios::binary);