X-Git-Url: http://git.linex4red.de/pub/lufa.git/blobdiff_plain/64f17a679f0d99741fb8101f02dfb3ef084e525c..d5d9ff73e5216969aaa2915de3fa04f530ffe400:/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c

diff --git a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c
index 7b0c5dda5..24df348f0 100644
--- a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c
+++ b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c
@@ -34,40 +34,63 @@ static const FATBootBlock_t BootBlock =
 	{
 		.Bootstrap               = {0xEB, 0x3C, 0x90},
 		.Description             = "mkdosfs",
-		.BlockSize               = VIRTUAL_MEMORY_BLOCK_SIZE,
-		.BlocksPerAllocationUnit = ALLOCATION_UNIT_BLOCKS,
-		.ReservedBlocks          = 1,
+		.SectorSize              = SECTOR_SIZE_BYTES,
+		.SectorsPerCluster       = SECTOR_PER_CLUSTER,
+		.ReservedSectors         = 1,
 		.FATCopies               = 2,
-		.RootDirectoryEntries    = 512,
-		.TotalBlocks16           = LUN_MEDIA_BLOCKS,
+		.RootDirectoryEntries    = (SECTOR_SIZE_BYTES / sizeof(FATDirectoryEntry_t)),
+		.TotalSectors16          = LUN_MEDIA_BLOCKS,
 		.MediaDescriptor         = 0xF8,
-		.BlocksPerFAT            = 1,
-		.BlocksPerTrack          = 32,
-		.Heads                   = 64,
-		.HiddenBlocks            = 0,
-		.TotalBlocks32           = 0,
+		.SectorsPerFAT           = 1,
+		.SectorsPerTrack         = LUN_MEDIA_BLOCKS % 64,
+		.Heads                   = LUN_MEDIA_BLOCKS / 64,
+		.HiddenSectors           = 0,
+		.TotalSectors32          = 0,
 		.PhysicalDriveNum        = 0,
 		.ExtendedBootRecordSig   = 0x29,
 		.VolumeSerialNumber      = 0x12345678,
 		.VolumeLabel             = "LUFA BOOT  ",
-		.FilesystemIdentifier    = "FAT16   ",
+		.FilesystemIdentifier    = "FAT12   ",
 		.BootstrapProgram        = {0},
 		.MagicSignature          = 0xAA55,
 	};
 
 static FATDirectoryEntry_t FirmwareFileEntry =
 	{
-		.Filename        = "Firmware",
-		.Extension       = "bin",
+		.Filename        = "FIRMWARE",
+		.Extension       = "BIN",
 		.Attributes      = 0,
 		.Reserved        = {0},
-		.CreationTime    = (1 << 11) | (1 << 5),
-		.CreationDate    = (9 << 9)  | (2 << 5) | (14 << 0),
-		.StartingCluster = 4,
-		.FileSize        = (FLASHEND + 1UL),
+		.CreationTime    = FAT_TIME(1, 1, 0),
+		.CreationDate    = FAT_DATE(14, 2, 1989),
+		.StartingCluster = 2,
+		.FileSizeBytes   = FIRMWARE_FILE_SIZE,
 	};
 
-static void WriteBlock(uint16_t BlockNumber)
+
+static void UpdateFAT12ClusterEntry(uint8_t* FATTable,
+                                    const uint16_t Index,
+                                    const uint16_t ChainEntry)
+{
+	/* Calculate the starting offset of the cluster entry in the FAT12 table */
+	uint8_t FATOffset   =   (Index * 3) / 2;
+	bool    UpperNibble = (((Index * 3) % 2) != 0);
+
+	/* Check if the start of the entry is at an upper nibble of the byte, fill
+	 * out FAT12 entry as required */
+	if (UpperNibble)
+	{
+		FATTable[FATOffset]     = (FATTable[FATOffset] & 0x0F) | ((ChainEntry & 0x0F) << 4);
+		FATTable[FATOffset + 1] = (ChainEntry >> 4);
+	}
+	else
+	{
+		FATTable[FATOffset]     = ChainEntry;
+		FATTable[FATOffset + 1] = (FATTable[FATOffset] & 0xF0) | (ChainEntry >> 8);
+	}
+}
+
+static void WriteBlock(const uint16_t BlockNumber)
 {
 	uint8_t BlockBuffer[512];
 
@@ -81,7 +104,7 @@ static void WriteBlock(uint16_t BlockNumber)
 	// TODO: Write to FLASH
 }
 
-static void ReadBlock(uint16_t BlockNumber)
+static void ReadBlock(const uint16_t BlockNumber)
 {
 	uint8_t BlockBuffer[512];
 	memset(BlockBuffer, 0x00, sizeof(BlockBuffer));
@@ -95,25 +118,17 @@ static void ReadBlock(uint16_t BlockNumber)
 		case 1:
 		case 2:
 			/* Cluster 0: Media type/Reserved */
-			((uint16_t*)&BlockBuffer)[0] = 0xFF00 | BootBlock.MediaDescriptor;
+			UpdateFAT12ClusterEntry(BlockBuffer, 0, 0xF00 | BootBlock.MediaDescriptor);
 
 			/* Cluster 1: Reserved */
-			((uint16_t*)&BlockBuffer)[1] = 0xFFFF;
-
-			/* Cluster 2: Reserved */
-			((uint16_t*)&BlockBuffer)[2] = 0xFFFF;
+			UpdateFAT12ClusterEntry(BlockBuffer, 1, 0xFFF);
 
-			/* Cluster 3: FIRMWARE.BIN File Entry */
-			((uint16_t*)&BlockBuffer)[3] = 0xFFFF;
-
-			/* Cluster 4 onwards: Cluster chain of FIRMWARE.BIN */
-			for (uint16_t i = 0; i < ((FLASHEND + 1) / (VIRTUAL_MEMORY_BLOCK_SIZE * ALLOCATION_UNIT_BLOCKS)); i++)
-			{
-				((uint16_t*)&BlockBuffer)[i + 4] = i + 5;
-			}
+			/* Cluster 2 onwards: Cluster chain of FIRMWARE.BIN */
+			for (uint16_t i = 0; i < FILE_CLUSTERS(FIRMWARE_FILE_SIZE); i++)
+			  UpdateFAT12ClusterEntry(BlockBuffer, i+2, i+3);
 
 			/* Mark last cluster as end of file */
-			((uint16_t*)&BlockBuffer)[((FLASHEND + 1) / (VIRTUAL_MEMORY_BLOCK_SIZE * ALLOCATION_UNIT_BLOCKS)) + 4] = 0xFFFF;
+			UpdateFAT12ClusterEntry(BlockBuffer, FILE_CLUSTERS(FIRMWARE_FILE_SIZE) + 1, 0xFFF);
 			break;
 
 		case 3:
@@ -121,6 +136,12 @@ static void ReadBlock(uint16_t BlockNumber)
 			break;
 
 		default:
+			if ((BlockNumber >= 4) && (BlockNumber < (4 + (FIRMWARE_FILE_SIZE / SECTOR_SIZE_BYTES))))
+			{
+				for (uint16_t i = 0; i < 512; i++)
+				  BlockBuffer[i] = 'A' + (i % 26);
+			}
+
 			break;
 	}
 
@@ -138,6 +159,8 @@ 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 */
 	while (TotalBlocks--)
 	  WriteBlock(CurrentBlock++);
 }
@@ -148,6 +171,8 @@ 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 */
 	while (TotalBlocks--)
 	  ReadBlock(CurrentBlock++);
 }