Add LED flashing to the incomplete Mass Storage class bootloader. Clean up virtual FAT implementation.

Bootloaders/Incomplete/MassStorage/BootloaderMassStorage.c

@@ -30,8 +30,7 @@
 
 /** \file
  *
- *  Main source file for the MassStorage demo. This file contains the main tasks of
- *  the demo and is responsible for the initial application hardware configuration.
+ *  Main source file for the Mass Storage class bootloader. This file contains the complete bootloader logic.
  */
 
 #include "BootloaderMassStorage.h"
@@ -96,6 +95,16 @@ void SetupHardware(void)
 	/* Hardware Initialization */
 	LEDs_Init();
 	USB_Init();
+
+	/* Bootloader active LED toggle timer initialization */
+	TIMSK1 = (1 << TOIE1);
+	TCCR1B = ((1 << CS11) | (1 << CS10));
+}
+
+/** ISR to periodically toggle the LEDs on the board to indicate that the bootloader is active. */
+ISR(TIMER1_OVF_vect, ISR_BLOCK)
+{
+	LEDs_ToggleLEDs(LEDS_LED1 | LEDS_LED2);
 }
 
 /** Event handler for the library USB Connection event. */

Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c

@@ -94,10 +94,7 @@ static void WriteBlock(const uint16_t BlockNumber)
 {
 	uint8_t BlockBuffer[SECTOR_SIZE_BYTES];
 
-	/* Wait until endpoint is ready before continuing */
-	if (Endpoint_WaitUntilReady())
-	  return;
-
+	/* Buffer the entire block to be written from the host */
 	Endpoint_Read_Stream_LE(BlockBuffer, sizeof(BlockBuffer), NULL);
 	Endpoint_ClearOUT();
 
@@ -139,12 +136,12 @@ static void ReadBlock(const uint16_t BlockNumber)
 
 	switch (BlockNumber)
 	{
-		case 0:
+		case 0: /* Block 0: Boot block sector */
 			memcpy(BlockBuffer, &BootBlock, sizeof(FATBootBlock_t));
 			break;
 
-		case 1:
-		case 2:
+		case 1: /* Block 1: First FAT12 cluster chain copy */
+		case 2: /* Block 2: Second FAT12 cluster chain copy */
 			/* Cluster 0: Media type/Reserved */
 			UpdateFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor);
 
@@ -159,11 +156,11 @@ static void ReadBlock(const uint16_t BlockNumber)
 			UpdateFAT12ClusterEntry(BlockBuffer, FILE_CLUSTERS(FIRMWARE_FILE_SIZE) + 1, 0xFFF);
 			break;
 
-		case 3:
+		case 3: /* Block 3: Root file entries */
 			memcpy(BlockBuffer, &FirmwareFileEntry, sizeof(FATDirectoryEntry_t));
 			break;
 
-		default:
+		default: /* Blocks 4 onwards: Data allocation section */
 			if ((BlockNumber >= 4) && (BlockNumber < (4 + (FIRMWARE_FILE_SIZE / SECTOR_SIZE_BYTES))))
 			{
 				uint32_t ReadFlashAddress = (uint32_t)(BlockNumber - 4) * SECTOR_SIZE_BYTES;
@@ -175,10 +172,7 @@ static void ReadBlock(const uint16_t BlockNumber)
 			break;
 	}
 
-	/* Wait until endpoint is ready before continuing */
-	if (Endpoint_WaitUntilReady())
-	  return;
-
+	/* Write the entire read block Buffer to the host */
 	Endpoint_Write_Stream_LE(BlockBuffer, sizeof(BlockBuffer), NULL);
 	Endpoint_ClearIN();
 }
@@ -190,7 +184,7 @@ void VirtualFAT_WriteBlocks(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo,
 	uint16_t CurrentBlock = (uint16_t)BlockAddress;
 
 	/* Emulated FAT is performed per-block, pass each requested block index
-	 * to the emulation function */
+	 * to the emulated FAT block write function */
 	while (TotalBlocks--)
 	  WriteBlock(CurrentBlock++);
 }
@@ -202,7 +196,7 @@ void VirtualFAT_ReadBlocks(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo,
 	uint16_t CurrentBlock = (uint16_t)BlockAddress;
 
 	/* Emulated FAT is performed per-block, pass each requested block index
-	 * to the emulation function */
+	 * to the emulated FAT block read function */
 	while (TotalBlocks--)
 	  ReadBlock(CurrentBlock++);
 }