int fatfs_fat_set_cluster(struct fatfs *fs, UINT32 cluster, UINT32 next_cluster)
{
struct sector_buffer *pbuf;
UINT32 fat_sector_offset, position;
// Find which sector of FAT table to read
if (fs->fat_type == FAT_TYPE_16)
fat_sector_offset = cluster / 256;
else
fat_sector_offset = cluster / 128;
// Read FAT sector into buffer
pbuf = fatfs_fat_read_sector(fs, fs->fat_begin_lba+fat_sector_offset);
if (!pbuf)
return 0;
if (fs->fat_type == FAT_TYPE_16)
{
// Find 16 bit entry of current sector relating to cluster number
position = (cluster - (fat_sector_offset * 256)) * 2;
// Write Next Clusters value to Sector Buffer
FAT16_SET_16BIT_WORD(pbuf, (UINT16)position, ((UINT16)next_cluster));
}
else
{
// Find 32 bit entry of current sector relating to cluster number
position = (cluster - (fat_sector_offset * 128)) * 4;
// Write Next Clusters value to Sector Buffer
FAT32_SET_32BIT_WORD(pbuf, (UINT16)position, next_cluster);
}
return 1;
}
//-----------------------------------------------------------------------------
// fatfs_set_fs_info_next_free_cluster: Write the next free cluster to the FSINFO table
//-----------------------------------------------------------------------------
void fatfs_set_fs_info_next_free_cluster(struct fatfs *fs, UINT32 newValue)
{
if (fs->fat_type == FAT_TYPE_16)
;
else
{
// Load sector to change it
struct sector_buffer *pbuf = fatfs_fat_read_sector(fs, fs->lba_begin+fs->fs_info_sector);
if (!pbuf)
return ;
// Change
FAT32_SET_32BIT_WORD(pbuf, 492, newValue);
fs->next_free_cluster = newValue;
}
}
//-----------------------------------------------------------------------------
// fatfs_set_fs_info_next_free_cluster: Write the next free cluster to the FSINFO table
//-----------------------------------------------------------------------------
void fatfs_set_fs_info_next_free_cluster(struct fatfs *fs, uint32 newValue)
{
if (fs->fat_type == FAT_TYPE_16)
;
else
{
// Load sector to change it
struct fat_buffer *pbuf = fatfs_fat_read_sector(fs, fs->lba_begin+fs->fs_info_sector);
if (!pbuf)
return ;
// Change
FAT32_SET_32BIT_WORD(pbuf, 492, newValue);
fs->next_free_cluster = newValue;
// Write back FSINFO sector to disk
if (fs->disk_io.write_media)
fs->disk_io.write_media(pbuf->address, pbuf->sector, 1);
// Invalidate cache entry
pbuf->address = FAT32_INVALID_CLUSTER;
pbuf->dirty = 0;
}
}
