Add EEPROM read/write support to the Mass Storage class bootloader.
authorDean Camera <dean@fourwalledcubicle.com>
Sat, 30 Mar 2013 17:16:29 +0000 (17:16 +0000)
committerDean Camera <dean@fourwalledcubicle.com>
Sat, 30 Mar 2013 17:16:29 +0000 (17:16 +0000)
Bootloaders/MassStorage/Lib/VirtualFAT.c
Bootloaders/MassStorage/Lib/VirtualFAT.h

index 2772c17..fd17618 100644 (file)
@@ -95,61 +95,110 @@ static FATDirectoryEntry_t FirmwareFileEntries[] =
                /* VFAT Long File Name entry for the virtual firmware file; required to
                 * prevent corruption from systems that are unable to detect the device
                 * as being a legacy MSDOS style FAT12 volume. */
-               [DISK_FILE_ENTRY_FirmwareLFN] =
+               [DISK_FILE_ENTRY_FLASH_LFN] =
                {
                        .VFAT_LongFileName =
                                {
-                                       .Ordinal         = FAT_ORDINAL_LAST_ENTRY | 1,
+                                       .Ordinal         = 1 | FAT_ORDINAL_LAST_ENTRY,
                                        .Attribute       = FAT_FLAG_LONG_FILE_NAME,
                                        .Reserved1       = 0,
                                        .Reserved2       = 0,
 
-                                       .Checksum        = 0x57,
+                                       .Checksum        = FAT_CHECKSUM('F','L','A','S','H',' ',' ',' ','B','I','N'),
 
                                        .Unicode1        = 'F',
-                                       .Unicode2        = 'I',
-                                       .Unicode3        = 'R',
-                                       .Unicode4        = 'M',
-                                       .Unicode5        = 'W',
-                                       .Unicode6        = 'A',
-                                       .Unicode7        = 'R',
-                                       .Unicode8        = 'E',
-                                       .Unicode9        = '.',
-                                       .Unicode10       = 'B',
-                                       .Unicode11       = 'I',
-                                       .Unicode12       = 'N',
+                                       .Unicode2        = 'L',
+                                       .Unicode3        = 'A',
+                                       .Unicode4        = 'S',
+                                       .Unicode5        = 'H',
+                                       .Unicode6        = '.',
+                                       .Unicode7        = 'B',
+                                       .Unicode8        = 'I',
+                                       .Unicode9        = 'N',
+                                       .Unicode10       = 0,
+                                       .Unicode11       = 0,
+                                       .Unicode12       = 0,
                                        .Unicode13       = 0,
                                }
                },
 
                /* MSDOS file entry for the virtual Firmware image. */
-               [DISK_FILE_ENTRY_FirmwareMSDOS] =
+               [DISK_FILE_ENTRY_FLASH_MSDOS] =
                {
                        .MSDOS_File =
                                {
-                                       .Filename        = "FIRMWARE",
+                                       .Filename        = "FLASH   ",
                                        .Extension       = "BIN",
                                        .Attributes      = 0,
                                        .Reserved        = {0},
                                        .CreationTime    = FAT_TIME(1, 1, 0),
                                        .CreationDate    = FAT_DATE(14, 2, 1989),
                                        .StartingCluster = 2,
-                                       .FileSizeBytes   = FIRMWARE_FILE_SIZE_BYTES,
+                                       .FileSizeBytes   = FLASH_FILE_SIZE_BYTES,
+                               }
+               },
+
+               [DISK_FILE_ENTRY_EEPROM_LFN] =
+               {
+                       .VFAT_LongFileName =
+                               {
+                                       .Ordinal         = 1 | FAT_ORDINAL_LAST_ENTRY,
+                                       .Attribute       = FAT_FLAG_LONG_FILE_NAME,
+                                       .Reserved1       = 0,
+                                       .Reserved2       = 0,
+
+                                       .Checksum        = FAT_CHECKSUM('E','E','P','R','O','M',' ',' ','B','I','N'),
+
+                                       .Unicode1        = 'E',
+                                       .Unicode2        = 'E',
+                                       .Unicode3        = 'P',
+                                       .Unicode4        = 'R',
+                                       .Unicode5        = 'O',
+                                       .Unicode6        = 'M',
+                                       .Unicode7        = '.',
+                                       .Unicode8        = 'B',
+                                       .Unicode9        = 'I',
+                                       .Unicode10       = 'N',
+                                       .Unicode11       = 0,
+                                       .Unicode12       = 0,
+                                       .Unicode13       = 0,
+                               }
+               },
+
+               [DISK_FILE_ENTRY_EEPROM_MSDOS] =
+               {
+                       .MSDOS_File =
+                               {
+                                       .Filename        = "EEPROM  ",
+                                       .Extension       = "BIN",
+                                       .Attributes      = 0,
+                                       .Reserved        = {0},
+                                       .CreationTime    = FAT_TIME(1, 1, 0),
+                                       .CreationDate    = FAT_DATE(14, 2, 1989),
+                                       .StartingCluster = 2 + FILE_CLUSTERS(FLASH_FILE_SIZE_BYTES),
+                                       .FileSizeBytes   = EEPROM_FILE_SIZE_BYTES,
                                }
                },
        };
 
-/** Starting cluster of the virtual firmware file on disk, tracked so that the
+/** Starting cluster of the virtual FLASH.BIN file on disk, tracked so that the
  *  offset from the start of the data sector can be determined. On Windows
  *  systems files are usually replaced using the original file's disk clusters,
  *  while Linux appears to overwrite with an offset which must be compensated for.
  */
-static uint16_t* FileStartCluster = &FirmwareFileEntries[DISK_FILE_ENTRY_FirmwareMSDOS].MSDOS_File.StartingCluster;
+static uint16_t* FLASHFileStartCluster  = &FirmwareFileEntries[DISK_FILE_ENTRY_FLASH_MSDOS].MSDOS_File.StartingCluster;
+
+/** Starting cluster of the virtual EEPROM.BIN file on disk, tracked so that the
+ *  offset from the start of the data sector can be determined. On Windows
+ *  systems files are usually replaced using the original file's disk clusters,
+ *  while Linux appears to overwrite with an offset which must be compensated for.
+ */
+static uint16_t* EEPROMFileStartCluster = &FirmwareFileEntries[DISK_FILE_ENTRY_EEPROM_MSDOS].MSDOS_File.StartingCluster;
 
 
 /** Updates a FAT12 cluster entry in the FAT file table with the specified next
  *  chain index. If the cluster is the last in the file chain, the magic value
- *  0xFFF is used.
+ *  \c 0xFFF should be used.
  *
  *  \note FAT data cluster indexes are offset by 2, so that cluster 2 is the
  *        first file data cluster on the disk. See the FAT specification.
@@ -180,21 +229,48 @@ static void UpdateFAT12ClusterEntry(uint8_t* const FATTable,
        }
 }
 
+/** Updates a FAT12 cluster chain in the FAT file table with a linear chain of
+ *  the specified length.
+ *
+ *  \note FAT data cluster indexes are offset by 2, so that cluster 2 is the
+ *        first file data cluster on the disk. See the FAT specification.
+ *
+ *  \param[out]  FATTable     Pointer to the FAT12 allocation table
+ *  \param[in]   Index        Index of the start of the cluster chain to update
+ *  \param[in]   ChainLength  Length of the chain to write, in clusters
+ */
+static void UpdateFAT12ClusterChain(uint8_t* const FATTable,
+                                    const uint16_t Index,
+                                    const uint16_t ChainLength)
+{
+       for (uint16_t i = 0; i < ChainLength; i++)
+       {
+               uint16_t CurrentCluster = Index + i;
+               uint16_t NextCluster    = CurrentCluster + 1;
+
+               /* Mark last cluster as end of file */
+               if (i == (ChainLength - 1))
+                 NextCluster = 0xFFF;
+
+               UpdateFAT12ClusterEntry(FATTable, CurrentCluster, NextCluster);
+       }
+}
+
 /** Reads or writes a block of data from/to the physical device FLASH using a
  *  block buffer stored in RAM, if the requested block is within the virtual
  *  firmware file's sector ranges in the emulated FAT file system.
  *
- *  \param[in]      BlockNumber  Physical disk block to read from
+ *  \param[in]      BlockNumber  Physical disk block to read from/write to
  *  \param[in,out]  BlockBuffer  Pointer to the start of the block buffer in RAM
  *  \param[in]      Read         If \c true, the requested block is read, if
  *                               \c false, the requested block is written
  */
-static void ReadWriteFirmwareFileBlock(const uint16_t BlockNumber,
-                                       uint8_t* BlockBuffer,
-                                       const bool Read)
+static void ReadWriteFLASHFileBlock(const uint16_t BlockNumber,
+                                    uint8_t* BlockBuffer,
+                                    const bool Read)
 {
-       uint16_t FileStartBlock = DISK_BLOCK_DataStartBlock + (*FileStartCluster - 2) * SECTOR_PER_CLUSTER;
-       uint16_t FileEndBlock   = FileStartBlock + (FILE_SECTORS(FIRMWARE_FILE_SIZE_BYTES) - 1);
+       uint16_t FileStartBlock = DISK_BLOCK_DataStartBlock + (*FLASHFileStartCluster - 2) * SECTOR_PER_CLUSTER;
+       uint16_t FileEndBlock   = FileStartBlock + (FILE_SECTORS(FLASH_FILE_SIZE_BYTES) - 1);
 
        /* Range check the write request - abort if requested block is not within the
         * virtual firmware file sector range */
@@ -243,6 +319,43 @@ static void ReadWriteFirmwareFileBlock(const uint16_t BlockNumber,
        }
 }
 
+/** Reads or writes a block of data from/to the physical device EEPROM using a
+ *  block buffer stored in RAM, if the requested block is within the virtual
+ *  firmware file's sector ranges in the emulated FAT file system.
+ *
+ *  \param[in]      BlockNumber  Physical disk block to read from/write to
+ *  \param[in,out]  BlockBuffer  Pointer to the start of the block buffer in RAM
+ *  \param[in]      Read         If \c true, the requested block is read, if
+ *                               \c false, the requested block is written
+ */
+static void ReadWriteEEPROMFileBlock(const uint16_t BlockNumber,
+                                     uint8_t* BlockBuffer,
+                                     const bool Read)
+{
+       uint16_t FileStartBlock = DISK_BLOCK_DataStartBlock + (*EEPROMFileStartCluster - 2) * SECTOR_PER_CLUSTER;
+       uint16_t FileEndBlock   = FileStartBlock + (FILE_SECTORS(EEPROM_FILE_SIZE_BYTES) - 1);
+
+       /* Range check the write request - abort if requested block is not within the
+        * virtual firmware file sector range */
+       if (!((BlockNumber >= FileStartBlock) && (BlockNumber <= FileEndBlock)))
+         return;
+
+       uint16_t EEPROMAddress = (uint16_t)(BlockNumber - FileStartBlock) * SECTOR_SIZE_BYTES;
+
+       if (Read)
+       {
+               /* Read out the mapped block of data from the device's EEPROM */
+               for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++)
+                 BlockBuffer[i] = eeprom_read_byte((void*)EEPROMAddress++);
+       }
+       else
+       {
+               /* Write out the mapped block of data to the device's EEPROM */
+               for (uint16_t i = 0; i < SECTOR_SIZE_BYTES; i++)
+                 eeprom_update_byte((void*)EEPROMAddress++, BlockBuffer[i]);
+       }
+}
+
 /** Writes a block of data to the virtual FAT filesystem, from the USB Mass
  *  Storage interface.
  *
@@ -272,7 +385,8 @@ void VirtualFAT_WriteBlock(const uint16_t BlockNumber)
                        break;
 
                default:
-                       ReadWriteFirmwareFileBlock(BlockNumber, BlockBuffer, false);
+                       ReadWriteFLASHFileBlock(BlockNumber, BlockBuffer, false);
+                       ReadWriteEEPROMFileBlock(BlockNumber, BlockBuffer, false);
 
                        break;
        }
@@ -307,18 +421,11 @@ void VirtualFAT_ReadBlock(const uint16_t BlockNumber)
                        /* Cluster 1: Reserved */
                        UpdateFAT12ClusterEntry(BlockBuffer, 1, 0xFFF);
 
-                       /* Cluster 2 onwards: Cluster chain of FIRMWARE.BIN */
-                       for (uint16_t i = 0; i <= FILE_CLUSTERS(FIRMWARE_FILE_SIZE_BYTES); i++)
-                       {
-                               uint16_t CurrentCluster = *FileStartCluster + i;
-                               uint16_t NextCluster    = CurrentCluster + 1;
-
-                               /* Mark last cluster as end of file */
-                               if (i == FILE_CLUSTERS(FIRMWARE_FILE_SIZE_BYTES))
-                                 NextCluster = 0xFFF;
+                       /* Cluster 2 onwards: Cluster chain of FLASH.BIN */
+                       UpdateFAT12ClusterChain(BlockBuffer, *FLASHFileStartCluster, FILE_CLUSTERS(FLASH_FILE_SIZE_BYTES));
 
-                               UpdateFAT12ClusterEntry(BlockBuffer, CurrentCluster, NextCluster);
-                       }
+                       /* Cluster 2+n onwards: Cluster chain of EEPROM.BIN */
+                       UpdateFAT12ClusterChain(BlockBuffer, *EEPROMFileStartCluster, FILE_CLUSTERS(EEPROM_FILE_SIZE_BYTES));
 
                        break;
 
@@ -328,7 +435,8 @@ void VirtualFAT_ReadBlock(const uint16_t BlockNumber)
                        break;
 
                default:
-                       ReadWriteFirmwareFileBlock(BlockNumber, BlockBuffer, true);
+                       ReadWriteFLASHFileBlock(BlockNumber, BlockBuffer, true);
+                       ReadWriteEEPROMFileBlock(BlockNumber, BlockBuffer, true);
 
                        break;
        }
index d01f9be..845530e 100644 (file)
                #include "../BootloaderAPI.h"
 
        /* Macros: */
-               /** Size of the virtual FIRMWARE.BIN file in bytes. */
-               #define FIRMWARE_FILE_SIZE_BYTES  (FLASHEND - (FLASHEND - BOOT_START_ADDR) - AUX_BOOT_SECTION_SIZE)
+               /** Size of the virtual FLASH.BIN file in bytes. */
+               #define FLASH_FILE_SIZE_BYTES     (FLASHEND - (FLASHEND - BOOT_START_ADDR) - AUX_BOOT_SECTION_SIZE)
+
+               /** Size of the virtual EEPROM.BIN file in bytes. */
+               #define EEPROM_FILE_SIZE_BYTES    E2END
 
                /** Number of sectors that comprise a single logical disk cluster. */
                #define SECTOR_PER_CLUSTER        4
@@ -69,7 +72,7 @@
                #define FILE_CLUSTERS(size)       ((size / CLUSTER_SIZE_BYTES) + ((size % CLUSTER_SIZE_BYTES) ? 1 : 0))
 
                /** Total number of logical sectors/blocks on the disk. */
-               #define LUN_MEDIA_BLOCKS          (FILE_SECTORS(FIRMWARE_FILE_SIZE_BYTES) + 32)
+               #define LUN_MEDIA_BLOCKS          (FILE_SECTORS(FLASH_FILE_SIZE_BYTES) + FILE_SECTORS(EEPROM_FILE_SIZE_BYTES) + 32)
 
                /** Converts a given time in HH:MM:SS format to a FAT filesystem time.
                 *
                 */
                #define FAT_DATE(dd, mm, yyyy)    (((yyyy - 1980) << 9) | (mm << 5) | (dd << 0))
 
+               /** Bit-rotates a given 8-bit value once to the right.
+                *
+                *  \param x  Value to rotate right once
+                *
+                *  \return Bit-rotated input value, rotated once to the right.
+                */
+               #define _ROT8(x)                  ((((x) & 0xFE) >> 1) | (((x) & 1) ? 0x80 : 0x00))
+
+               /** Computes the LFN entry checksum of a MSDOS 8.3 format file entry,
+                *  to associate a LFN entry with its short file entry.
+                *
+                *  \param n0  MSDOS Filename character 1
+                *  \param n1  MSDOS Filename character 2
+                *  \param n2  MSDOS Filename character 3
+                *  \param n3  MSDOS Filename character 4
+                *  \param n4  MSDOS Filename character 5
+                *  \param n5  MSDOS Filename character 6
+                *  \param n6  MSDOS Filename character 7
+                *  \param n7  MSDOS Filename character 8
+                *  \param e0  MSDOS Extension character 1
+                *  \param e1  MSDOS Extension character 2
+                *  \param e2  MSDOS Extension character 3
+                *
+                *  \return LFN checksum of the given MSDOS 8.3 filename.
+                */
+               #define FAT_CHECKSUM(n0, n1, n2, n3, n4, n5, n6, n7, e0, e1, e2) \
+                  (uint8_t)(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(_ROT8(n0)+n1)+n2)+n3)+n4)+n5)+n6)+n7)+e0)+e1)+e2)
+
                /** \name FAT Filesystem Flags */
                //@{
                /** FAT attribute flag to indicate a read-only file. */
                {
                        /** Volume ID directory entry, giving the name of the virtual disk. */
                        DISK_FILE_ENTRY_VolumeID      = 0,
-                       /** Long File Name FAT file entry of the virtual firmware image file. */
-                       DISK_FILE_ENTRY_FirmwareLFN   = 1,
-                       /** Legacy MSDOS FAT file entry of the virtual firmware image file. */
-                       DISK_FILE_ENTRY_FirmwareMSDOS = 2,
+                       /** Long File Name FAT file entry of the virtual FLASH.BIN image file. */
+                       DISK_FILE_ENTRY_FLASH_LFN     = 1,
+                       /** Legacy MSDOS FAT file entry of the virtual FLASH.BIN image file. */
+                       DISK_FILE_ENTRY_FLASH_MSDOS   = 2,
+                       /** Long File Name FAT file entry of the virtual EEPROM.BIN image file. */
+                       DISK_FILE_ENTRY_EEPROM_LFN    = 3,
+                       /** Legacy MSDOS FAT file entry of the virtual EEPROM.BIN image file. */
+                       DISK_FILE_ENTRY_EEPROM_MSDOS  = 4,
                };
 
                /** Enum for the physical disk blocks of the virtual disk. */
                                                            const uint16_t Index,
                                                            const uint16_t ChainEntry) AUX_BOOT_SECTION;
 
-                       static void ReadWriteFirmwareFileBlock(const uint16_t BlockNumber,
-                                                              uint8_t* BlockBuffer,
-                                                              const bool Read) AUX_BOOT_SECTION;
+                       static void UpdateFAT12ClusterChain(uint8_t* const FATTable,
+                                                           const uint16_t StartIndex,
+                                                           const uint16_t ChainLength) AUX_BOOT_SECTION;
+
+                       static void ReadWriteFLASHFileBlock(const uint16_t BlockNumber,
+                                                           uint8_t* BlockBuffer,
+                                                           const bool Read) AUX_BOOT_SECTION;
+
+                       static void ReadWriteEEPROMFileBlock(const uint16_t BlockNumber,
+                                                            uint8_t* BlockBuffer,
+                                                            const bool Read) AUX_BOOT_SECTION;
                #endif
 
                void VirtualFAT_WriteBlock(const uint16_t BlockNumber) AUX_BOOT_SECTION;