add seek()

acia.h

@@ -46,6 +46,6 @@ public:
 	static const uint8_t eri = 1 << 7;	// enable receive interrupt
 
 private:
-	serialio *_device;
+	class serialio *_device;
 };
 #endif

flash_filer.cpp

@@ -22,6 +22,15 @@ static File file;
 static Dir dir;
 #endif
 
+bool flash_filer::seek(uint32_t pos)
+{
+#if defined(USE_SD) || defined(USE_SPIFFS) || defined(USE_FS)
+	_pos = _len = 0;
+	return file.seek(pos);
+#endif
+	return false;
+}
+
 bool flash_filer::start()
 {
 #if defined(USE_FS)

flash_filer.h

@@ -15,6 +15,7 @@ public:
 
 	bool start();
 	void stop();
+	bool seek(uint32_t pos);
 	
 	uint8_t read() { return _buf[_pos++]; }
 	bool more();