/* * Copyright © 2013 Keith Packard * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #ifndef AO_FAT_TEST #include "ao.h" #endif #include "ao_fat.h" #include "ao_bufio.h" /* Include FAT commands */ #ifndef AO_FAT_TEST #define FAT_COMMANDS 1 #endif /* Spew FAT tracing */ #define FAT_TRACE 0 #if FAT_TRACE #define DBG(...) printf(__VA_ARGS__) #else #define DBG(...) #endif /* * 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 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) #define SECTOR_SHIFT 9 #define DIRENT_SIZE 32 /* File system parameters */ 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 */ static uint32_t get_u32(uint8_t *base) { return ((uint32_t) base[0] | ((uint32_t) base[1] << 8) | ((uint32_t) base[2] << 16) | ((uint32_t) base[3] << 24)); } static void put_u32(uint8_t *base, uint32_t value) { base[0] = value; base[1] = value >> 8; base[2] = value >> 16; base[3] = value >> 24; } static uint16_t get_u16(uint8_t *base) { return ((uint16_t) base[0] | ((uint16_t) base[1] << 8)); } static void put_u16(uint8_t *base, uint16_t value) { base[0] = value; base[1] = value >> 8; } static uint8_t ao_fat_cluster_valid(cluster_t cluster) { return (2 <= cluster && cluster < number_cluster); } /* Start using a sector */ static uint8_t * ao_fat_sector_get(sector_t sector) { sector += partition_start; if (sector >= partition_end) return NULL; return ao_bufio_get(sector); } /* Finish using a sector, 'w' is 1 if modified */ #define ao_fat_sector_put(b,w) ao_bufio_put(b,w) /* Get the next cluster entry in the chain */ static cluster_t ao_fat_entry_read(cluster_t cluster) { sector_t sector; cluster_t offset; uint8_t *buf; cluster_t ret; if (!ao_fat_cluster_valid(cluster)) 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; 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; } /* Replace the referenced cluster entry in the chain with * 'new_value'. Return the previous value. */ static cluster_t ao_fat_entry_replace(cluster_t cluster, cluster_t new_value) { 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 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); } return ret; } /* * Walk a cluster chain and mark * all of them as free */ static void ao_fat_free_cluster_chain(cluster_t cluster) { while (ao_fat_cluster_valid(cluster)) { if (cluster < next_free) { next_free = cluster; fsinfo_dirty = 1; } cluster = ao_fat_entry_replace(cluster, 0x00000000); } } /* * ao_fat_cluster_seek * * The basic file system operation -- map a file cluster index to a * partition cluster number. Done by computing the cluster number and * then walking that many clusters from the first cluster. Returns * 0xffff if we walk off the end of the file or the cluster chain * is damaged somehow */ static cluster_t ao_fat_cluster_seek(cluster_t cluster, cluster_t distance) { while (distance) { cluster = ao_fat_entry_read(cluster); if (!ao_fat_cluster_valid(cluster)) break; 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 root directory at least 'ents' entries long */ 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 * * Load the boot block and find the first partition */ static uint8_t ao_fat_setup_partition(void) { uint8_t *mbr; uint8_t *partition; uint32_t partition_size; mbr = ao_bufio_get(0); if (!mbr) return AO_FAT_FILESYSTEM_MBR_READ_FAILURE; /* Check the signature */ if (mbr[0x1fe] != 0x55 || mbr[0x1ff] != 0xaa) { DBG ("Invalid MBR signature %02x %02x\n", mbr[0x1fe], mbr[0x1ff]); ao_bufio_put(mbr, 0); return AO_FAT_FILESYSTEM_INVALID_MBR_SIGNATURE; } /* Check to see if it's actually a boot block, in which * case it's presumably not a paritioned device */ if (mbr[0] == 0xeb) { partition_start = 0; partition_size = get_u16(mbr + 0x13); if (partition_size == 0) partition_size = get_u32(mbr + 0x20); } else { /* Just use the first partition */ partition = &mbr[0x1be]; partition_type = partition[4]; switch (partition_type) { case 4: /* FAT16 up to 32M */ case 6: /* FAT16 over 32M */ break; case 0x0b: /* FAT32 up to 2047GB */ case 0x0c: /* FAT32 LBA */ break; default: DBG ("Invalid partition type %02x\n", partition_type); ao_bufio_put(mbr, 0); return AO_FAT_FILESYSTEM_INVALID_PARTITION_TYPE; } partition_start = get_u32(partition+8); partition_size = get_u32(partition+12); if (partition_size == 0) { DBG ("Zero-sized partition\n"); ao_bufio_put(mbr, 0); return AO_FAT_FILESYSTEM_ZERO_SIZED_PARTITION; } } partition_end = partition_start + partition_size; ao_bufio_put(mbr, 0); return AO_FAT_FILESYSTEM_SUCCESS; } static uint8_t ao_fat_setup_fs(void) { uint8_t *boot = ao_fat_sector_get(0); uint32_t data_sectors; if (!boot) return AO_FAT_FILESYSTEM_BOOT_READ_FAILURE; /* Check the signature */ if (boot[0x1fe] != 0x55 || boot[0x1ff] != 0xaa) { DBG ("Invalid BOOT signature %02x %02x\n", boot[0x1fe], boot[0x1ff]); ao_fat_sector_put(boot, 0); return AO_FAT_FILESYSTEM_INVALID_BOOT_SIGNATURE; } /* Check the sector size */ if (get_u16(boot + 0xb) != SECTOR_SIZE) { DBG ("Invalid sector size %d\n", get_u16(boot + 0xb)); ao_fat_sector_put(boot, 0); return AO_FAT_FILESYSTEM_INVALID_SECTOR_SIZE; } sectors_per_cluster = boot[0xd]; bytes_per_cluster = sectors_per_cluster << SECTOR_SHIFT; reserved_sector_count = get_u16(boot+0xe); 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; data_start = root_start + ((root_entries * DIRENT_SIZE + SECTOR_MASK) >> SECTOR_SHIFT); data_sectors = (partition_end - partition_start) - data_start; number_cluster = data_sectors / sectors_per_cluster; return AO_FAT_FILESYSTEM_SUCCESS; } /* * 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_filesystem_setup; static uint8_t ao_filesystem_status; static uint8_t ao_fat_setup(void) { if (!ao_filesystem_setup) { ao_filesystem_setup = 1; ao_bufio_setup(); /* Re-initialize all global state; this will help to allow the * file system to get swapped someday */ 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; ao_filesystem_status = ao_fat_setup_partition(); if (ao_filesystem_status != AO_FAT_FILESYSTEM_SUCCESS) return ao_filesystem_status; ao_filesystem_status = ao_fat_setup_fs(); if (ao_filesystem_status != AO_FAT_FILESYSTEM_SUCCESS) return ao_filesystem_status; } return ao_filesystem_status; } void ao_fat_unmount(void) { ao_filesystem_setup = 0; } /* * Basic file operations */ static uint32_t ao_fat_current_sector(void) { cluster_t cluster_offset; uint32_t sector_offset; uint16_t sector_index; cluster_t cluster; DBG("current sector offset %d size %d\n", ao_file_offset, ao_file_dirent.size); if (ao_file_offset > ao_file_dirent.size) return 0xffffffff; sector_offset = ao_file_offset >> SECTOR_SHIFT; if (!ao_file_cluster || ao_file_offset < ao_file_cluster_offset) { ao_file_cluster = ao_file_dirent.cluster; ao_file_cluster_offset = 0; DBG("\treset to start of file %08x\n", ao_file_cluster); } if (ao_file_cluster_offset + bytes_per_cluster <= ao_file_offset) { cluster_t cluster_distance; cluster_offset = sector_offset / sectors_per_cluster; cluster_distance = cluster_offset - ao_file_cluster_offset / bytes_per_cluster; DBG("\tseek forward %d clusters\n", cluster_distance); cluster = ao_fat_cluster_seek(ao_file_cluster, cluster_distance); if (!ao_fat_cluster_valid(cluster)) return 0xffffffff; ao_file_cluster = cluster; ao_file_cluster_offset = cluster_offset * bytes_per_cluster; } sector_index = sector_offset % sectors_per_cluster; DBG("current cluster %08x sector_index %d sector %d\n", ao_file_cluster, sector_index, data_start + (uint32_t) (ao_file_cluster-2) * sectors_per_cluster + sector_index); return data_start + (uint32_t) (ao_file_cluster-2) * sectors_per_cluster + sector_index; } static void ao_fat_set_offset(uint32_t offset) { DBG("Set offset %d\n", offset); ao_file_offset = offset; } /* * ao_fat_set_size * * Set the size of the current file, truncating or extending * the cluster chain as needed */ static int8_t ao_fat_set_size(uint32_t size) { uint8_t *dent; cluster_t first_cluster; cluster_t have_clusters, need_clusters; DBG ("Set size %d\n", size); if (size == ao_file_dirent.size) { DBG("\tsize match\n"); return AO_FAT_SUCCESS; } 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; DBG ("\tfirst cluster %08x have %d need %d\n", first_cluster, have_clusters, need_clusters); 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; DBG ("\tset size relative offset_clusters %d extra_clusters %d\n", offset_clusters, extra_clusters); next_cluster = ao_fat_cluster_set_size(ao_file_cluster, extra_clusters); if (next_cluster == AO_FAT_BAD_CLUSTER) return -AO_FAT_ENOSPC; } else { DBG ("\tset size absolute need_clusters %d\n", need_clusters); first_cluster = ao_fat_cluster_set_size(first_cluster, need_clusters); if (first_cluster == AO_FAT_BAD_CLUSTER) return -AO_FAT_ENOSPC; } } DBG ("\tupdate directory size\n"); /* 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; DBG ("set size done\n"); return AO_FAT_SUCCESS; } /* * ao_fat_root_init * * Initialize a root directory entry */ static void ao_fat_root_init(uint8_t *dent, char name[11], uint8_t attr) { memset(dent, '\0', 0x20); memmove(dent, name, 11); dent[0x0b] = 0x00; dent[0x0c] = 0x00; dent[0x0d] = 0x00; /* XXX fix time */ put_u16(dent + 0x0e, 0); /* XXX fix date */ put_u16(dent + 0x10, 0); /* XXX fix date */ put_u16(dent + 0x12, 0); /* XXX fix time */ put_u16(dent + 0x16, 0); /* XXX fix date */ put_u16(dent + 0x18, 0); /* cluster number */ /* Low cluster bytes */ put_u16(dent + 0x1a, 0); /* FAT32 high cluster bytes */ put_u16(dent + 0x14, 0); /* size */ put_u32(dent + 0x1c, 0); } static void ao_fat_dirent_init(uint8_t *dent, uint16_t entry, struct ao_fat_dirent *dirent) { memcpy(dirent->name, dent + 0x00, 11); 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 */ static 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 */ /* * ao_fat_sync * * Flush any pending I/O to storage */ void ao_fat_sync(void) { if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) return; ao_fat_flush_fsinfo(); ao_bufio_flush(); } /* * ao_fat_full * * Returns TRUE if the filesystem cannot take * more data */ int8_t ao_fat_full(void) { if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) return 1; return filesystem_full; } /* * ao_fat_open * * Open an existing file. */ int8_t ao_fat_open(char name[11], uint8_t mode) { uint16_t entry = 0; struct ao_fat_dirent dirent; if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) return -AO_FAT_EIO; if (ao_file_opened) return -AO_FAT_EMFILE; while (ao_fat_readdir(&entry, &dirent)) { if (!memcmp(name, dirent.name, 11)) { if (AO_FAT_IS_DIR(dirent.attr)) return -AO_FAT_EISDIR; if (!AO_FAT_IS_FILE(dirent.attr)) return -AO_FAT_EPERM; if (mode > AO_FAT_OPEN_READ && (dirent.attr & AO_FAT_FILE_READ_ONLY)) return -AO_FAT_EACCESS; ao_file_dirent = dirent; ao_fat_set_offset(0); ao_file_opened = 1; return AO_FAT_SUCCESS; } } return -AO_FAT_ENOENT; } /* * ao_fat_creat * * Open and truncate an existing file or * create a new file */ int8_t ao_fat_creat(char name[11]) { uint16_t entry; int8_t status; uint8_t *dent; if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) return -AO_FAT_EIO; if (ao_file_opened) return -AO_FAT_EMFILE; status = ao_fat_open(name, AO_FAT_OPEN_WRITE); switch (status) { case -AO_FAT_SUCCESS: status = ao_fat_set_size(0); break; case -AO_FAT_ENOENT: entry = 0; for (;;) { dent = ao_fat_root_get(entry); if (!dent) { if (ao_fat_root_extend(entry)) continue; status = -AO_FAT_ENOSPC; break; } if (dent[0] == AO_FAT_DENT_EMPTY || dent[0] == AO_FAT_DENT_END) { ao_fat_root_init(dent, name, AO_FAT_FILE_REGULAR); ao_fat_dirent_init(dent, entry, &ao_file_dirent); ao_fat_root_put(dent, entry, 1); ao_file_opened = 1; ao_fat_set_offset(0); status = -AO_FAT_SUCCESS; break; } else { ao_fat_root_put(dent, entry, 0); } entry++; } } return status; } /* * ao_fat_close * * Close the currently open file */ int8_t ao_fat_close(void) { if (!ao_file_opened) return -AO_FAT_EBADF; memset(&ao_file_dirent, '\0', sizeof (struct ao_fat_dirent)); ao_file_offset = 0; ao_file_cluster = 0; ao_file_opened = 0; ao_fat_sync(); return AO_FAT_SUCCESS; } /* * ao_fat_map_current * * Map the sector pointed at by the current file offset */ static void * ao_fat_map_current(int len, cluster_offset_t *offsetp, cluster_offset_t *this_time) { cluster_offset_t offset; sector_t sector; void *buf; offset = ao_file_offset & SECTOR_MASK; sector = ao_fat_current_sector(); if (sector == 0xffffffff) return NULL; buf = ao_fat_sector_get(sector); if (offset + len < SECTOR_SIZE) *this_time = len; else *this_time = SECTOR_SIZE - offset; *offsetp = offset; return buf; } /* * ao_fat_read * * Read from the file */ int ao_fat_read(void *dst, int len) { uint8_t *dst_b = dst; cluster_offset_t this_time; cluster_offset_t offset; uint8_t *buf; int ret = 0; if (!ao_file_opened) return -AO_FAT_EBADF; if (ao_file_offset + len > ao_file_dirent.size) len = ao_file_dirent.size - ao_file_offset; if (len < 0) len = 0; while (len) { buf = ao_fat_map_current(len, &offset, &this_time); if (!buf) { ret = -AO_FAT_EIO; break; } memcpy(dst_b, buf + offset, this_time); ao_fat_sector_put(buf, 0); ret += this_time; len -= this_time; dst_b += this_time; ao_fat_set_offset(ao_file_offset + this_time); } return ret; } /* * ao_fat_write * * Write to the file, extended as necessary */ int ao_fat_write(void *src, int len) { uint8_t *src_b = src; uint16_t this_time; uint16_t offset; uint8_t *buf; int ret = 0; if (!ao_file_opened) return -AO_FAT_EBADF; if (ao_file_offset + len > ao_file_dirent.size) { ret = ao_fat_set_size(ao_file_offset + len); if (ret < 0) return ret; } while (len) { buf = ao_fat_map_current(len, &offset, &this_time); if (!buf) { ret = -AO_FAT_EIO; break; } memcpy(buf + offset, src_b, this_time); ao_fat_sector_put(buf, 1); ret += this_time; len -= this_time; src_b += this_time; ao_fat_set_offset(ao_file_offset + this_time); } return ret; } /* * ao_fat_seek * * Set the position for the next I/O operation * Note that this doesn't actually change the size * of the file if the requested position is beyond * the current file length, that would take a future * write */ int32_t ao_fat_seek(int32_t pos, uint8_t whence) { uint32_t new_offset = ao_file_offset; if (!ao_file_opened) return -AO_FAT_EBADF; switch (whence) { case AO_FAT_SEEK_SET: new_offset = pos; break; case AO_FAT_SEEK_CUR: new_offset += pos; break; case AO_FAT_SEEK_END: new_offset = ao_file_dirent.size + pos; break; } ao_fat_set_offset(new_offset); return ao_file_offset; } /* * ao_fat_unlink * * Remove a file from the directory, marking * all clusters as free */ int8_t ao_fat_unlink(char name[11]) { uint16_t entry = 0; struct ao_fat_dirent dirent; if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) return -AO_FAT_EIO; while (ao_fat_readdir(&entry, &dirent)) { if (memcmp(name, dirent.name, 11) == 0) { uint8_t *next; uint8_t *ent; uint8_t delete; if (AO_FAT_IS_DIR(dirent.attr)) return -AO_FAT_EISDIR; if (!AO_FAT_IS_FILE(dirent.attr)) return -AO_FAT_EPERM; ao_fat_free_cluster_chain(dirent.cluster); next = ao_fat_root_get(dirent.entry + 1); if (next && next[0] != AO_FAT_DENT_END) delete = AO_FAT_DENT_EMPTY; else delete = AO_FAT_DENT_END; if (next) ao_fat_root_put(next, dirent.entry + 1, 0); ent = ao_fat_root_get(dirent.entry); if (ent) { memset(ent, '\0', DIRENT_SIZE); *ent = delete; ao_fat_root_put(ent, dirent.entry, 1); } ao_bufio_flush(); return AO_FAT_SUCCESS; } } return -AO_FAT_ENOENT; } int8_t ao_fat_rename(char old[11], char new[11]) { return -AO_FAT_EIO; } int8_t ao_fat_readdir(uint16_t *entry, struct ao_fat_dirent *dirent) { uint8_t *dent; if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) return -AO_FAT_EIO; 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); return 0; } if (dent[0] != AO_FAT_DENT_EMPTY && (dent[0xb] & 0xf) != 0xf) { ao_fat_dirent_init(dent, *entry, dirent); ao_fat_root_put(dent, *entry, 0); (*entry)++; return 1; } ao_fat_root_put(dent, *entry, 0); (*entry)++; } } #if FAT_COMMANDS static const char *filesystem_errors[] = { [AO_FAT_FILESYSTEM_SUCCESS] = "FAT file system operating normally", [AO_FAT_FILESYSTEM_MBR_READ_FAILURE] = "MBR media read error", [AO_FAT_FILESYSTEM_INVALID_MBR_SIGNATURE] = "MBR signature invalid", [AO_FAT_FILESYSTEM_INVALID_PARTITION_TYPE] = "Unsupported paritition type", [AO_FAT_FILESYSTEM_ZERO_SIZED_PARTITION] = "Partition has zero sectors", [AO_FAT_FILESYSTEM_BOOT_READ_FAILURE] = "Boot block media read error", [AO_FAT_FILESYSTEM_INVALID_BOOT_SIGNATURE] = "Boot block signature invalid", [AO_FAT_FILESYSTEM_INVALID_SECTOR_SIZE] = "Sector size not 512", }; static void ao_fat_mbr_cmd(void) { uint8_t status; status = ao_fat_setup(); if (status == AO_FAT_FILESYSTEM_SUCCESS) { printf ("partition type: %02x\n", partition_type); printf ("partition start: %08x\n", partition_start); printf ("partition end: %08x\n", partition_end); 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); printf ("root entries %d\n", root_entries); printf ("sectors per fat %d\n", sectors_per_fat); printf ("fat start %d\n", fat_start); printf ("root start %d\n", root_start); printf ("data start %d\n", data_start); } else { printf ("FAT filesystem not available: %s\n", filesystem_errors[status]); } } struct ao_fat_attr { uint8_t bit; char label; }; static const struct ao_fat_attr ao_fat_attr[] = { { .bit = AO_FAT_FILE_READ_ONLY, .label = 'R' }, { .bit = AO_FAT_FILE_HIDDEN, .label = 'H' }, { .bit = AO_FAT_FILE_SYSTEM, .label = 'S' }, { .bit = AO_FAT_FILE_VOLUME_LABEL, .label = 'V' }, { .bit = AO_FAT_FILE_DIRECTORY, .label = 'D' }, { .bit = AO_FAT_FILE_ARCHIVE, .label = 'A' }, }; #define NUM_FAT_ATTR (sizeof (ao_fat_attr) / sizeof (ao_fat_attr[0])) static void ao_fat_list_cmd(void) { uint16_t entry = 0; struct ao_fat_dirent dirent; int i; while (ao_fat_readdir(&entry, &dirent)) { for (i = 0; i < 8; i++) putchar(dirent.name[i]); putchar('.'); for (; i < 11; i++) putchar(dirent.name[i]); for (i = 0; i < NUM_FAT_ATTR; i++) putchar (dirent.attr & ao_fat_attr[i].bit ? ao_fat_attr[i].label : ' '); printf (" @%08x %d\n", dirent.cluster, dirent.size); } } static uint8_t ao_fat_parse_name(char name[11]) { uint8_t c; name[0] = '\0'; ao_cmd_white(); c = 0; while (ao_cmd_lex_c != '\n') { if (ao_cmd_lex_c == '.') { for (; c < 8; c++) name[c] = ' '; } else { if (c < 11) name[c++] = ao_cmd_lex_c; } ao_cmd_lex(); } } static void ao_fat_show_cmd(void) { char name[11]; int8_t status; int cnt, i; char buf[64]; ao_fat_parse_name(name); if (name[0] == '\0') { ao_cmd_status = ao_cmd_syntax_error; return; } status = ao_fat_open(name, AO_FAT_OPEN_READ); if (status) { printf ("Open failed: %d\n", status); return; } while ((cnt = ao_fat_read(buf, sizeof(buf))) > 0) { for (i = 0; i < cnt; i++) putchar(buf[i]); } ao_fat_close(); } static void ao_fat_putchar(char c) { } static void ao_fat_write_cmd(void) { char name[11]; int8_t status; int cnt, i; char buf[64]; char c; ao_fat_parse_name(name); if (name[0] == '\0') { ao_cmd_status = ao_cmd_syntax_error; return; } status = ao_fat_creat(name); if (status) { printf ("Open failed: %d\n", status); return; } flush(); while ((c = getchar()) != 4) { if (c == '\r') c = '\n'; if (ao_echo()) { if (c == '\n') putchar ('\r'); putchar(c); flush(); } if (ao_fat_write(&c, 1) != 1) { printf ("Write failure\n"); break; } } ao_fat_close(); } static const struct ao_cmds ao_fat_cmds[] = { { ao_fat_mbr_cmd, "M\0Show FAT MBR and other info" }, { ao_fat_list_cmd, "F\0List FAT directory" }, { ao_fat_show_cmd, "S \0Show FAT file" }, { ao_fat_write_cmd, "W \0Write FAT file (end with ^D)" }, { 0, NULL }, }; #endif void ao_fat_init(void) { ao_bufio_init(); ao_cmd_register(&ao_fat_cmds[0]); }