From 7f5dab4f261e08972d3f31512c970c29e54707d1 Mon Sep 17 00:00:00 2001
From: Dean Camera <dean@fourwalledcubicle.com>
Date: Sat, 9 Mar 2013 08:00:22 +0000
Subject: [PATCH] Refactor macros in the VirtualFAT implementation of the
 incomplete Mass Storage bootloader.

---
 Bootloaders/Incomplete/MassStorage/Lib/SCSI.c    |  4 ++--
 .../Incomplete/MassStorage/Lib/VirtualFAT.c      | 16 ++++++----------
 .../Incomplete/MassStorage/Lib/VirtualFAT.h      | 12 +++++++++---
 3 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/Bootloaders/Incomplete/MassStorage/Lib/SCSI.c b/Bootloaders/Incomplete/MassStorage/Lib/SCSI.c
index c6596d41a1..7ab149ccd2 100644
--- a/Bootloaders/Incomplete/MassStorage/Lib/SCSI.c
+++ b/Bootloaders/Incomplete/MassStorage/Lib/SCSI.c
@@ -214,7 +214,7 @@ static bool SCSI_Command_Request_Sense(USB_ClassInfo_MS_Device_t* const MSInterf
 static bool SCSI_Command_Read_Capacity_10(USB_ClassInfo_MS_Device_t* const MSInterfaceInfo)
 {
 	uint32_t LastBlockAddressInLUN = (LUN_MEDIA_BLOCKS - 1);
-	uint32_t MediaBlockSize        = VIRTUAL_MEMORY_BLOCK_SIZE;
+	uint32_t MediaBlockSize        = SECTOR_SIZE_BYTES;
 
 	Endpoint_Write_Stream_BE(&LastBlockAddressInLUN, sizeof(LastBlockAddressInLUN), NULL);
 	Endpoint_Write_Stream_BE(&MediaBlockSize, sizeof(MediaBlockSize), NULL);
@@ -292,7 +292,7 @@ static bool SCSI_Command_ReadWrite_10(USB_ClassInfo_MS_Device_t* const MSInterfa
 	  VirtualFAT_WriteBlocks(MSInterfaceInfo, BlockAddress, TotalBlocks);
 
 	/* Update the bytes transferred counter and succeed the command */
-	MSInterfaceInfo->State.CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * VIRTUAL_MEMORY_BLOCK_SIZE);
+	MSInterfaceInfo->State.CommandBlock.DataTransferLength -= ((uint32_t)TotalBlocks * SECTOR_SIZE_BYTES);
 
 	return true;
 }
diff --git a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c
index 2365ba5839..883586c3d6 100644
--- a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c
+++ b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.c
@@ -30,15 +30,6 @@
 
 #include "VirtualFAT.h"
 
-#define FAT_TIME(h, m, s)      ((h << 11) | (m << 5) | (s >> 1))
-#define FAT_DATE(d, m, y)      (((y - 1980) << 9) | (m << 5) | (d << 0))
-
-#define SECTOR_SIZE_BYTES      VIRTUAL_MEMORY_BLOCK_SIZE
-#define SECTOR_PER_CLUSTER     4
-#define CLUSTER_SIZE_BYTES     (SECTOR_PER_CLUSTER * SECTOR_SIZE_BYTES)
-
-#define FILE_CLUSTERS(size)    (size / CLUSTER_SIZE_BYTES)
-
 static const FATBootBlock_t BootBlock =
 	{
 		.Bootstrap               = {0xEB, 0x3C, 0x90},
@@ -47,7 +38,7 @@ static const FATBootBlock_t BootBlock =
 		.SectorsPerCluster       = SECTOR_PER_CLUSTER,
 		.ReservedSectors         = 1,
 		.FATCopies               = 2,
-		.RootDirectoryEntries    = SECTOR_SIZE_BYTES / sizeof(FATDirectoryEntry_t),
+		.RootDirectoryEntries    = (SECTOR_SIZE_BYTES / sizeof(FATDirectoryEntry_t)),
 		.TotalSectors16          = LUN_MEDIA_BLOCKS,
 		.MediaDescriptor         = 0xF8,
 		.SectorsPerFAT           = 1,
@@ -76,6 +67,7 @@ static FATDirectoryEntry_t FirmwareFileEntry =
 		.FileSizeBytes   = 2049,
 	};
 
+
 static void WriteBlock(uint16_t BlockNumber)
 {
 	uint8_t BlockBuffer[512];
@@ -156,6 +148,8 @@ 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++);
 }
@@ -166,6 +160,8 @@ 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++);
 }
diff --git a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.h b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.h
index 760fb40646..156760afd8 100644
--- a/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.h
+++ b/Bootloaders/Incomplete/MassStorage/Lib/VirtualFAT.h
@@ -38,11 +38,17 @@
 		#include <LUFA/Drivers/USB/USB.h>
 
 	/* Macros: */
-		#define VIRTUAL_MEMORY_BLOCK_SIZE 512
+		#define FIRMWARE_FILE_SIZE     (FLASHEND + 1UL)
+		#define FILE_CLUSTERS(size)    ((size / CLUSTER_SIZE_BYTES) + ((size % CLUSTER_SIZE_BYTES) ? 1 : 0))
 
-		#define FIRMWARE_FILE_SIZE        (FLASHEND + 1UL)
+		#define SECTOR_SIZE_BYTES      512
+		#define SECTOR_PER_CLUSTER     4
+		#define CLUSTER_SIZE_BYTES     (SECTOR_PER_CLUSTER * SECTOR_SIZE_BYTES)
 
-		#define LUN_MEDIA_BLOCKS          ((FIRMWARE_FILE_SIZE / VIRTUAL_MEMORY_BLOCK_SIZE) + 32)
+		#define LUN_MEDIA_BLOCKS       ((FIRMWARE_FILE_SIZE / SECTOR_SIZE_BYTES) + 32)
+
+		#define FAT_TIME(h, m, s)      ((h << 11) | (m << 5) | (s >> 1))
+		#define FAT_DATE(d, m, y)      (((y - 1980) << 9) | (m << 5) | (d << 0))
 
 	/* Type Definitions: */
 		typedef struct