LCD Driver, some teensy code, SDCard code, MBR/FAT32

ext/sd/MBR.h

@@ -0,0 +1,73 @@
+#pragma once 
+
+template <typename BlockDev> class MBR {
+	
+	BlockDev& dev;
+	bool present = false;
+	bool valid = false;
+	
+	/** describes one partition */
+	class Partition {
+		
+		friend class MBR;
+		
+		uint8_t type;
+		uint32_t firstSector;
+		uint32_t numSectors;
+		
+	public:
+		
+		bool isPresent() const {return type != 0;}
+		uint8_t getType() const {return type;}
+		uint32_t getFirstSector() const {return firstSector;}
+		uint32_t getNumSectors() const {return numSectors;}
+		
+	};
+	
+	Partition partitions[4];
+	
+public:
+
+	MBR(BlockDev& dev) : dev(dev) {
+		read();
+	}
+	
+	bool isPresent() const {return present;}
+	bool isValid() const {return valid;}
+	
+	Partition& getPartition(uint8_t idx) {
+		return partitions[idx];
+	}
+	
+private:
+		
+	void read() {
+		
+		uint8_t buf[512];
+		dev.read(0x00000000, 512, buf);
+		present = (buf[510] == 0x55) && (buf[511] == 0xAA);
+		valid = (buf[0x01BC] == 0x00) && (buf[0x01BD] == 0x00);
+		
+		if (present && valid) {
+			
+			// parse all 4 partitions
+			for (uint8_t i = 0; i < 4; ++i) {
+				
+				const uint8_t* src = &buf[0x1BE + i*16];
+				Partition* p = &partitions[i];
+				
+				p->type = src[0x4];
+				p->firstSector = getU32(src, 8);
+				p->numSectors = getU32(src, 12);
+				
+			}
+			
+		}
+		
+	}
+	
+	uint32_t getU32(const uint8_t* src, const uint8_t offset) {
+		return src[offset+0]<<0 | src[offset+1]<<8 | src[offset+2]<<16 | src[offset+3]<<24;
+	}
+	
+};