X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fdrivers%2Fao_fat.c;fp=src%2Fdrivers%2Fao_fat.c;h=a19eff701564c04dc30fecbb2b656a920351cf20;hp=98f57d674c6c3e3cd647422b65972d6db9db8885;hb=86e1039e14304ac13db540f2ee3afd4ff170b8b4;hpb=44e418bbecd3a3deae942803141cf115d92f29d2 diff --git a/src/drivers/ao_fat.c b/src/drivers/ao_fat.c index 98f57d67..a19eff70 100644 --- a/src/drivers/ao_fat.c +++ b/src/drivers/ao_fat.c @@ -22,10 +22,26 @@ #include "ao_fat.h" #include "ao_bufio.h" +/* + * Basic file system types + */ + +typedef ao_fat_offset_t offset_t; +typedef ao_fat_sector_t sector_t; +typedef ao_fat_cluster_t cluster_t; +typedef ao_fat_dirent_t dirent_t; +typedef ao_fat_cluster_offset_t cluster_offset_t; + /* Partition information, sector numbers */ -static uint8_t partition_type; -static uint32_t partition_start, partition_end; +static uint8_t partition_type; +static sector_t partition_start, partition_end; + +#define AO_FAT_BAD_CLUSTER 0xffffff7 +#define AO_FAT_LAST_CLUSTER 0xfffffff +#define AO_FAT_IS_LAST_CLUSTER(c) (((c) & 0xffffff8) == 0xffffff8) +#define AO_FAT_IS_LAST_CLUSTER16(c) (((c) & 0xfff8) == 0xfff8) + #define SECTOR_SIZE 512 #define SECTOR_MASK (SECTOR_SIZE - 1) @@ -34,17 +50,25 @@ static uint32_t partition_start, partition_end; #define DIRENT_SIZE 32 /* File system parameters */ -static uint8_t sectors_per_cluster; -static uint32_t bytes_per_cluster; -static uint16_t reserved_sector_count; -static uint8_t number_fat; -static uint16_t root_entries; -static uint16_t sectors_per_fat; -static uint16_t number_cluster; -static uint32_t fat_start; -static uint32_t root_start; -static uint32_t data_start; -static uint16_t first_free_cluster; +static uint8_t sectors_per_cluster; +static uint32_t bytes_per_cluster; +static sector_t reserved_sector_count; +static uint8_t number_fat; +static dirent_t root_entries; +static sector_t sectors_per_fat; +static cluster_t number_cluster; +static sector_t fat_start; +static sector_t root_start; +static sector_t data_start; +static cluster_t next_free; +static uint8_t filesystem_full; + +/* FAT32 extra data */ +static uint8_t fat32; +static uint8_t fsinfo_dirty; +static cluster_t root_cluster; +static sector_t fsinfo_sector; +static cluster_t free_count; /* * Deal with LSB FAT data structures @@ -81,14 +105,14 @@ put_u16(uint8_t *base, uint16_t value) } static uint8_t -ao_fat_cluster_valid(uint16_t cluster) +ao_fat_cluster_valid(cluster_t cluster) { return (2 <= cluster && cluster < number_cluster); } /* Start using a sector */ static uint8_t * -ao_fat_sector_get(uint32_t sector) +ao_fat_sector_get(sector_t sector) { sector += partition_start; if (sector >= partition_end) @@ -99,49 +123,36 @@ ao_fat_sector_get(uint32_t sector) /* Finish using a sector, 'w' is 1 if modified */ #define ao_fat_sector_put(b,w) ao_bufio_put(b,w) -/* Start using a root directory entry */ -static uint8_t * -ao_fat_root_get(uint16_t e) -{ - uint32_t byte = e * DIRENT_SIZE; - uint32_t sector = byte >> SECTOR_SHIFT; - uint16_t offset = byte & SECTOR_MASK; - uint8_t *buf; - - buf = ao_fat_sector_get(root_start + sector); - if (!buf) - return NULL; - return buf + offset; -} - -/* Finish using a root directory entry, 'w' is 1 if modified */ -static void -ao_fat_root_put(uint8_t *root, uint16_t e, uint8_t write) -{ - uint16_t offset = ((e * DIRENT_SIZE) & SECTOR_MASK); - uint8_t *buf = root - offset; - - ao_fat_sector_put(buf, write); -} - /* Get the next cluster entry in the chain */ -static uint16_t -ao_fat_entry_read(uint16_t cluster) +static cluster_t +ao_fat_entry_read(cluster_t cluster) { - uint32_t sector; - uint16_t offset; + sector_t sector; + cluster_t offset; uint8_t *buf; - uint16_t ret; + cluster_t ret; if (!ao_fat_cluster_valid(cluster)) - return 0xfff7; - - sector = cluster >> (SECTOR_SHIFT - 1); - offset = (cluster << 1) & SECTOR_MASK; + return 0xfffffff7; + + if (fat32) + cluster <<= 2; + else + cluster <<= 1; + sector = cluster >> (SECTOR_SHIFT); + offset = cluster & SECTOR_MASK; buf = ao_fat_sector_get(fat_start + sector); if (!buf) return 0; - ret = get_u16(buf + offset); + + if (fat32) { + ret = get_u32(buf + offset); + ret &= 0xfffffff; + } else { + ret = get_u16(buf + offset); + if (AO_FAT_IS_LAST_CLUSTER16(ret)) + ret |= 0xfff0000; + } ao_fat_sector_put(buf, 0); return ret; } @@ -149,36 +160,60 @@ ao_fat_entry_read(uint16_t cluster) /* Replace the referenced cluster entry in the chain with * 'new_value'. Return the previous value. */ -static uint16_t -ao_fat_entry_replace(uint16_t cluster, uint16_t new_value) +static cluster_t +ao_fat_entry_replace(cluster_t cluster, cluster_t new_value) { - uint32_t sector; - uint16_t offset; - uint8_t *buf; - uint16_t ret; - uint8_t other_fats; + sector_t sector; + cluster_offset_t offset; + uint8_t *buf; + cluster_t ret; + cluster_t old_value; + uint8_t fat; if (!ao_fat_cluster_valid(cluster)) - return 0; - - sector = cluster >> (SECTOR_SHIFT - 1); - offset = (cluster << 1) & SECTOR_MASK; - buf = ao_fat_sector_get(fat_start + sector); - if (!buf) - return 0; - ret = get_u16(buf + offset); - put_u16(buf + offset, new_value); - ao_fat_sector_put(buf, 1); - - /* - * Keep the other FATs in sync - */ - for (other_fats = 1; other_fats < number_fat; other_fats++) { - buf = ao_fat_sector_get(fat_start + other_fats * sectors_per_fat + sector); - if (buf) { + return 0xfffffff7; + + /* Convert from cluster index to byte index */ + if (fat32) + cluster <<= 2; + else + cluster <<= 1; + sector = cluster >> SECTOR_SHIFT; + offset = cluster & SECTOR_MASK; + + new_value &= 0xfffffff; + for (fat = 0; fat < number_fat; fat++) { + buf = ao_fat_sector_get(fat_start + fat * sectors_per_fat + sector); + if (!buf) + return 0; + if (fat32) { + old_value = get_u32(buf + offset); + put_u32(buf + offset, new_value | (old_value & 0xf0000000)); + if (fat == 0) { + ret = old_value & 0xfffffff; + + /* Track the free count if it wasn't marked + * invalid when we mounted the file system + */ + if (free_count != 0xffffffff) { + if (new_value && !ret) { + --free_count; + fsinfo_dirty = 1; + } else if (!new_value && ret) { + ++free_count; + fsinfo_dirty = 1; + } + } + } + } else { + if (fat == 0) { + ret = get_u16(buf + offset); + if (AO_FAT_IS_LAST_CLUSTER16(ret)) + ret |= 0xfff0000; + } put_u16(buf + offset, new_value); - ao_fat_sector_put(buf, 1); } + ao_fat_sector_put(buf, 1); } return ret; @@ -189,12 +224,14 @@ ao_fat_entry_replace(uint16_t cluster, uint16_t new_value) * all of them as free */ static void -ao_fat_free_cluster_chain(uint16_t cluster) +ao_fat_free_cluster_chain(cluster_t cluster) { while (ao_fat_cluster_valid(cluster)) { - if (cluster < first_free_cluster) - first_free_cluster = cluster; - cluster = ao_fat_entry_replace(cluster, 0x0000); + if (cluster < next_free) { + next_free = cluster; + fsinfo_dirty = 1; + } + cluster = ao_fat_entry_replace(cluster, 0x00000000); } } @@ -207,8 +244,8 @@ ao_fat_free_cluster_chain(uint16_t cluster) * 0xffff if we walk off the end of the file or the cluster chain * is damaged somehow */ -static uint16_t -ao_fat_cluster_seek(uint16_t cluster, uint16_t distance) +static cluster_t +ao_fat_cluster_seek(cluster_t cluster, cluster_t distance) { while (distance) { cluster = ao_fat_entry_read(cluster); @@ -219,6 +256,176 @@ ao_fat_cluster_seek(uint16_t cluster, uint16_t distance) return cluster; } +/* + * ao_fat_cluster_set_size + * + * Set the number of clusters in the specified chain, + * freeing extra ones or alocating new ones as needed + * + * Returns AO_FAT_BAD_CLUSTER on allocation failure + */ + +static cluster_t +ao_fat_cluster_set_size(cluster_t first_cluster, cluster_t size) +{ + cluster_t clear_cluster = 0; + + if (size == 0) { + clear_cluster = first_cluster; + first_cluster = 0; + } else { + cluster_t have; + cluster_t last_cluster = 0; + cluster_t next_cluster; + + /* Walk the cluster chain to the + * spot where it needs to change. That + * will either be the end of the chain (in case it needs to grow), + * or after the desired number of clusters, in which case it needs to shrink + */ + next_cluster = first_cluster; + for (have = 0; have < size; have++) { + last_cluster = next_cluster; + next_cluster = ao_fat_entry_read(last_cluster); + if (!ao_fat_cluster_valid(next_cluster)) + break; + } + + if (have == size) { + /* The file is large enough, truncate as needed */ + if (ao_fat_cluster_valid(next_cluster)) { + /* Rewrite that cluster entry with 0xffff to mark the end of the chain */ + clear_cluster = ao_fat_entry_replace(last_cluster, AO_FAT_LAST_CLUSTER); + filesystem_full = 0; + } else { + /* The chain is already the right length, don't mess with it */ + ; + } + } else { + cluster_t need; + cluster_t free; + + if (filesystem_full) + return AO_FAT_BAD_CLUSTER; + + if (next_free < 2 || number_cluster <= next_free) { + next_free = 2; + fsinfo_dirty = 1; + } + + /* See if there are enough free clusters in the file system */ + need = size - have; + +#define loop_cluster for (free = next_free; need > 0;) +#define next_cluster \ + if (++free == number_cluster) \ + free = 2; \ + if (free == next_free) \ + break; \ + + loop_cluster { + if (!ao_fat_entry_read(free)) + need--; + next_cluster; + } + /* Still need some, tell the user that we've failed */ + if (need) { + filesystem_full = 1; + return AO_FAT_BAD_CLUSTER; + } + + /* Now go allocate those clusters and + * thread them onto the chain + */ + need = size - have; + loop_cluster { + if (!ao_fat_entry_read(free)) { + next_free = free + 1; + if (next_free >= number_cluster) + next_free = 2; + fsinfo_dirty = 1; + if (last_cluster) + ao_fat_entry_replace(last_cluster, free); + else + first_cluster = free; + last_cluster = free; + need--; + } + next_cluster; + } +#undef loop_cluster +#undef next_cluster + /* Mark the new end of the chain */ + ao_fat_entry_replace(last_cluster, AO_FAT_LAST_CLUSTER); + } + } + + /* Deallocate clusters off the end of the file */ + if (ao_fat_cluster_valid(clear_cluster)) + ao_fat_free_cluster_chain(clear_cluster); + return first_cluster; +} + +/* Start using a root directory entry */ +static uint8_t * +ao_fat_root_get(dirent_t e) +{ + offset_t byte = e * DIRENT_SIZE; + sector_t sector = byte >> SECTOR_SHIFT; + cluster_offset_t offset = byte & SECTOR_MASK; + uint8_t *buf; + + if (fat32) { + cluster_t cluster_distance = sector / sectors_per_cluster; + sector_t sector_index = sector % sectors_per_cluster; + cluster_t cluster = ao_fat_cluster_seek(root_cluster, cluster_distance); + + if (ao_fat_cluster_valid(cluster)) + sector = data_start + (cluster-2) * sectors_per_cluster + sector_index; + else + return NULL; + } else { + if (e >= root_entries) + return NULL; + sector = root_start + sector; + } + + buf = ao_fat_sector_get(sector); + if (!buf) + return NULL; + return buf + offset; +} + +/* Finish using a root directory entry, 'w' is 1 if modified */ +static void +ao_fat_root_put(uint8_t *root, dirent_t e, uint8_t write) +{ + cluster_offset_t offset = ((e * DIRENT_SIZE) & SECTOR_MASK); + uint8_t *buf = root - offset; + + ao_fat_sector_put(buf, write); +} + +/* + * ao_fat_root_extend + * + * On FAT32, make the + */ +static int8_t +ao_fat_root_extend(dirent_t ents) +{ + offset_t byte_size; + cluster_t cluster_size; + if (!fat32) + return 0; + + byte_size = ents * 0x20; + cluster_size = byte_size / bytes_per_cluster; + if (ao_fat_cluster_set_size(root_cluster, cluster_size) != AO_FAT_BAD_CLUSTER) + return 1; + return 0; +} + /* * ao_fat_setup_partition * @@ -316,6 +523,26 @@ ao_fat_setup_fs(void) number_fat = boot[0x10]; root_entries = get_u16(boot + 0x11); sectors_per_fat = get_u16(boot+0x16); + fat32 = 0; + if (sectors_per_fat == 0) { + fat32 = 1; + sectors_per_fat = get_u32(boot+0x24); + root_cluster = get_u32(boot+0x2c); + fsinfo_sector = get_u16(boot + 0x30); + } + ao_fat_sector_put(boot, 0); + + free_count = 0xffffffff; + next_free = 0; + if (fat32 && fsinfo_sector) { + uint8_t *fsinfo = ao_fat_sector_get(fsinfo_sector); + + if (fsinfo) { + free_count = get_u32(fsinfo + 0x1e8); + next_free = get_u32(fsinfo + 0x1ec); + ao_fat_sector_put(fsinfo, 0); + } + } fat_start = reserved_sector_count;; root_start = fat_start + number_fat * sectors_per_fat; @@ -325,6 +552,7 @@ ao_fat_setup_fs(void) number_cluster = data_sectors / sectors_per_cluster; + printf ("fat32: %d\n", fat32); printf ("sectors per cluster %d\n", sectors_per_cluster); printf ("reserved sectors %d\n", reserved_sector_count); printf ("number of FATs %d\n", number_fat); @@ -335,20 +563,35 @@ ao_fat_setup_fs(void) printf ("root start %d\n", root_start); printf ("data start %d\n", data_start); - ao_fat_sector_put(boot, 0); - return 1; } +/* + * State for the current opened file + */ +static struct ao_fat_dirent ao_file_dirent; +static uint32_t ao_file_offset; +static uint32_t ao_file_cluster_offset; +static cluster_t ao_file_cluster; +static uint8_t ao_file_opened; + static uint8_t ao_fat_setup(void) { + ao_bufio_setup(); + + partition_type = partition_start = partition_end = 0; + sectors_per_cluster = bytes_per_cluster = reserved_sector_count = 0; + number_fat = root_entries = sectors_per_fat = 0; + number_cluster = fat_start = root_start = data_start = 0; + next_free = filesystem_full = 0; + fat32 = fsinfo_dirty = root_cluster = fsinfo_sector = free_count = 0; + memset(&ao_file_dirent, '\0', sizeof (ao_file_dirent)); + ao_file_offset = ao_file_cluster_offset = ao_file_cluster = ao_file_opened = 0; if (!ao_fat_setup_partition()) return 0; - check_bufio("partition setup"); if (!ao_fat_setup_fs()) return 0; - check_bufio("fs setup"); return 1; } @@ -356,19 +599,13 @@ ao_fat_setup(void) * Basic file operations */ -static struct ao_fat_dirent ao_file_dirent; -static uint32_t ao_file_offset; -static uint32_t ao_file_cluster_offset; -static uint16_t ao_file_cluster; -static uint8_t ao_file_opened; - static uint32_t ao_fat_current_sector(void) { - uint16_t cluster_offset; + cluster_t cluster_offset; uint32_t sector_offset; uint16_t sector_index; - uint16_t cluster; + cluster_t cluster; if (ao_file_offset > ao_file_dirent.size) return 0xffffffff; @@ -381,7 +618,7 @@ ao_fat_current_sector(void) } if (ao_file_cluster_offset + bytes_per_cluster <= ao_file_offset) { - uint16_t cluster_distance; + cluster_t cluster_distance; cluster_offset = sector_offset / sectors_per_cluster; @@ -414,98 +651,44 @@ ao_fat_set_offset(uint32_t offset) static int8_t ao_fat_set_size(uint32_t size) { - uint16_t clear_cluster = 0; uint8_t *dent; - uint16_t first_cluster; + cluster_t first_cluster; + cluster_t have_clusters, need_clusters; - first_cluster = ao_file_dirent.cluster; if (size == ao_file_dirent.size) return AO_FAT_SUCCESS; - if (size == 0) { - clear_cluster = ao_file_dirent.cluster; - first_cluster = 0; - } else { - uint16_t new_num; - uint16_t old_num; - - new_num = (size + bytes_per_cluster - 1) / bytes_per_cluster; - old_num = (ao_file_dirent.size + bytes_per_cluster - 1) / bytes_per_cluster; - if (new_num < old_num) { - uint16_t last_cluster; - - /* Go find the last cluster we want to preserve in the file */ - last_cluster = ao_fat_cluster_seek(ao_file_dirent.cluster, new_num - 1); - - /* Rewrite that cluster entry with 0xffff to mark the end of the chain */ - clear_cluster = ao_fat_entry_replace(last_cluster, 0xffff); - } else if (new_num > old_num) { - uint16_t need; - uint16_t free; - uint16_t last_cluster; - uint16_t highest_allocated = 0; - - if (old_num) - last_cluster = ao_fat_cluster_seek(ao_file_dirent.cluster, old_num - 1); - else - last_cluster = 0; - if (first_free_cluster < 2 || number_cluster <= first_free_cluster) - first_free_cluster = 2; + first_cluster = ao_file_dirent.cluster; + have_clusters = (ao_file_dirent.size + bytes_per_cluster - 1) / bytes_per_cluster; + need_clusters = (size + bytes_per_cluster - 1) / bytes_per_cluster; - /* See if there are enough free clusters in the file system */ - need = new_num - old_num; + if (have_clusters != need_clusters) { + if (ao_file_cluster && size >= ao_file_cluster_offset) { + cluster_t offset_clusters = (ao_file_cluster_offset + bytes_per_cluster) / bytes_per_cluster; + cluster_t extra_clusters = need_clusters - offset_clusters; + cluster_t next_cluster; -#define loop_cluster for (free = first_free_cluster; need > 0;) -#define next_cluster \ - if (++free == number_cluster) \ - free = 2; \ - if (free == first_free_cluster) \ - break; \ - - loop_cluster { - if (!ao_fat_entry_read(free)) - need--; - next_cluster; - } - /* Still need some, tell the user that we've failed */ - if (need) + next_cluster = ao_fat_cluster_set_size(ao_file_cluster, extra_clusters); + if (next_cluster == AO_FAT_BAD_CLUSTER) return -AO_FAT_ENOSPC; + } else { + first_cluster = ao_fat_cluster_set_size(first_cluster, need_clusters); - /* Now go allocate those clusters */ - need = new_num - old_num; - loop_cluster { - if (!ao_fat_entry_read(free)) { - if (free > highest_allocated) - highest_allocated = free; - if (last_cluster) - ao_fat_entry_replace(last_cluster, free); - else - first_cluster = free; - last_cluster = free; - need--; - } - next_cluster; - } - first_free_cluster = highest_allocated + 1; - if (first_free_cluster >= number_cluster) - first_free_cluster = 2; - - /* Mark the new end of the chain */ - ao_fat_entry_replace(last_cluster, 0xffff); + if (first_cluster == AO_FAT_BAD_CLUSTER) + return -AO_FAT_ENOSPC; } } - /* Deallocate clusters off the end of the file */ - if (ao_fat_cluster_valid(clear_cluster)) - ao_fat_free_cluster_chain(clear_cluster); - /* Update the directory entry */ dent = ao_fat_root_get(ao_file_dirent.entry); if (!dent) return -AO_FAT_EIO; put_u32(dent + 0x1c, size); put_u16(dent + 0x1a, first_cluster); + if (fat32) + put_u16(dent + 0x14, first_cluster >> 16); ao_fat_root_put(dent, ao_file_dirent.entry, 1); + ao_file_dirent.size = size; ao_file_dirent.cluster = first_cluster; return AO_FAT_SUCCESS; @@ -556,9 +739,39 @@ ao_fat_dirent_init(uint8_t *dent, uint16_t entry, struct ao_fat_dirent *dirent) dirent->attr = dent[0x0b]; dirent->size = get_u32(dent+0x1c); dirent->cluster = get_u16(dent+0x1a); + if (fat32) + dirent->cluster |= (cluster_t) get_u16(dent + 0x14) << 16; dirent->entry = entry; } +/* + * ao_fat_flush_fsinfo + * + * Write out any fsinfo changes to disk + */ + +void +ao_fat_flush_fsinfo(void) +{ + uint8_t *fsinfo; + + if (!fat32) + return; + + if (!fsinfo_dirty) + return; + fsinfo_dirty = 0; + if (!fsinfo_sector) + return; + + fsinfo = ao_fat_sector_get(fsinfo_sector); + if (fsinfo) { + put_u32(fsinfo + 0x1e8, free_count); + put_u32(fsinfo + 0x1ec, next_free); + ao_fat_sector_put(fsinfo, 1); + } +} + /* * Public API */ @@ -605,6 +818,7 @@ ao_fat_creat(char name[11]) { uint16_t entry; int8_t status; + uint8_t *dent; if (ao_file_opened) return -AO_FAT_EMFILE; @@ -616,12 +830,14 @@ ao_fat_creat(char name[11]) status = ao_fat_set_size(0); break; case -AO_FAT_ENOENT: - for (entry = 0; entry < root_entries; entry++) { - uint8_t *dent = ao_fat_root_get(entry); - + entry = 0; + for (;;) { + dent = ao_fat_root_get(entry); if (!dent) { - status = -AO_FAT_EIO; - ao_fat_root_put(dent, entry, 0); + + if (ao_fat_root_extend(entry)) + continue; + status = -AO_FAT_ENOSPC; break; } @@ -636,9 +852,8 @@ ao_fat_creat(char name[11]) } else { ao_fat_root_put(dent, entry, 0); } + entry++; } - if (entry == root_entries) - status = -AO_FAT_ENOSPC; } return status; } @@ -658,6 +873,8 @@ ao_fat_close(void) ao_file_offset = 0; ao_file_cluster = 0; ao_file_opened = 0; + + ao_fat_flush_fsinfo(); ao_bufio_flush(); return AO_FAT_SUCCESS; } @@ -849,10 +1066,10 @@ ao_fat_readdir(uint16_t *entry, struct ao_fat_dirent *dirent) { uint8_t *dent; - if (*entry >= root_entries) - return 0; for (;;) { dent = ao_fat_root_get(*entry); + if (!dent) + return 0; if (dent[0] == AO_FAT_DENT_END) { ao_fat_root_put(dent, *entry, 0);