/***********************************************************************
*
* Function: fat16_init_device
*
* Purpose:
* Initializes the FAT16 interface for the selected device.
*
* Processing:
* Copy the device name and function pointers into the FAT device
* structure. Clear the commit flag to indicate the FAT cluster table
* does not need to be written back to the device. Call the device
* initialization function. If the device was initialized, read the
* MBR into the FAT device structure.
*
* Parameters:
* device : Device name
* init_func : Pointer to initialization function
* shutdown_func : Pointer to shutdown function
* insert_ck_func : Pointer to insertion check function
* ready_ck_func : Pointer to ready check function
* busy_ck_func : Pointer to bust check function
* set_sector_func : Pointer to sector set function
* start_read_func : Pointer to read start function
* start_write_func : Pointer to write start function
* read_func : Pointer to read buffer function
* write_func : Pointer to write buffer function
*
* Outputs:
* Data in fat_data will be updated.
*
* Returns:
* The pointer to a binded device structure, or NULL if the device
* was not detected.
*
* Notes:
* The calling function should check to make sure that NULL was not
* returned. If NULL was returned, the device does not exist or
* memory could not be allocated.
*
**********************************************************************/
FAT_DEVICE_TYPE * fat16_init_device(
CHAR *device, // Name of device
ivfunc init_func, // Pointer to device init function
vvfunc shutdown_func, // Pointer to device shutdown function
ivfunc insert_ck_func, // Pointer to check for insert func
ivfunc ready_ck_func, // Pointer for ready? check
ivfunc busy_ck_func, // Pointer for busy? check
void (*set_sector_func)(UNS_32), // sector setting
vvfunc start_read_func, // Pointer for read start
vvfunc start_write_func, // Pointer for write start
ivifunc read_func, // Pointer for read of data
ivifunc write_func) // Pointer for write of data
{
FAT_DEVICE_TYPE *fat_data = (FAT_DEVICE_TYPE *) NULL;
// Try to initialize the device
if (init_func() == 1)
{
// Device initiailized, allocate the device data structure
fat_data = lpc_new(sizeof(FAT_DEVICE_TYPE));
if (fat_data != NULL)
{
// Copy device name into device name in structure
fat16_moveto(device, fat_data->device, (DSIZE - 1));
fat_data->device [DSIZE - 1] = '\0';
// Save function pointers
fat_data->func.init_func = init_func;
fat_data->func.shutdown_func = shutdown_func;
fat_data->func.insert_ck_func = insert_ck_func;
fat_data->func.ready_ck_func = ready_ck_func;
fat_data->func.busy_ck_func = busy_ck_func;
fat_data->func.set_sector_func = set_sector_func;
fat_data->func.start_read_func = start_read_func;
fat_data->func.start_write_func = start_write_func;
fat_data->func.read_func = read_func;
fat_data->func.write_func = write_func;
// Set active partition to (-1), disable commit
fat_data->fat_commit = 0;
// Read MBR and populate MBR structure
fat16_read_mbr(fat_data);
}
}
return fat_data;
}
//returns zero on failure
int fat16_init() {
//read mbr sector
fat16_read_mbr((uint16_t*)mbr);
//read partition table
memcpy(part_table, mbr+MBR_OFFSET_PART_TABLE,sizeof(partition_table)*4);
selected_part = fat16_find_partition(part_table, TABLE_ENTRIES);
if(selected_part==-1)
return 0;
//start of boot sector
boot_start_lba = __SWAP32(part_table[selected_part].lba_offset);
//read fat boot sector
fat16_read_fat_boot(&fat_boot);
//start of root dir
root_dir_start_lba = (__SWAP16(fat_boot.reserved_sectors) + __SWAP16(fat_boot.fat_size_sectors) * fat_boot.number_of_fats) * __SWAP16(fat_boot.sector_size);
root_dir_start_lba /= 512;
root_dir_start_lba += boot_start_lba;
//start of cluster data:
data_start_lba = ((__SWAP16(fat_boot.reserved_sectors)
+ __SWAP16(fat_boot.fat_size_sectors)
* fat_boot.number_of_fats)
* __SWAP16(fat_boot.sector_size));
data_start_lba += __SWAP16(fat_boot.root_dir_entries)*0x20;
data_start_lba /= 512;
data_start_lba += boot_start_lba;
//start of FAT data
fat_start_lba = boot_start_lba+((__SWAP16(fat_boot.sector_size)*__SWAP16(fat_boot.reserved_sectors))/512);
//read FAT
fat = (uint16_t*) malloc(__SWAP16(fat_boot.fat_size_sectors)* __SWAP16(fat_boot.sector_size));
fat16_read_fat(fat);
cluster_size_bytes = __SWAP16(fat_boot.sector_size) * fat_boot.sectors_per_cluster;
cluster_size_lba = cluster_size_bytes/512;
return 1;
}
