diff options
Diffstat (limited to 'src/drivers/ao_fat.c')
| -rw-r--r-- | src/drivers/ao_fat.c | 1654 |
1 files changed, 1654 insertions, 0 deletions
diff --git a/src/drivers/ao_fat.c b/src/drivers/ao_fat.c new file mode 100644 index 00000000..afd645cd --- /dev/null +++ b/src/drivers/ao_fat.c @@ -0,0 +1,1654 @@ +/* + * Copyright © 2013 Keith Packard <keithp@keithp.com> + * + * 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 + +#ifdef DBG +#undef DBG +#endif + +#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; + +/* Global FAT lock */ +static uint8_t ao_fat_mutex; + +/* 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 have; + cluster_t last_cluster; + 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; + last_cluster = 0; + DBG("\tclusters:"); + for (have = 0; have < size; have++) { + DBG(" %08x", next_cluster); + if (!_ao_fat_cluster_valid(next_cluster)) + break; + last_cluster = next_cluster; + next_cluster = _ao_fat_entry_read(next_cluster); + } + DBG("\n"); + + /* At this point, last_cluster points to the last valid + * cluster in the file, if any. That's the spot in the FAT + * that needs to be rewritten, either to truncate the file by + * writing an END marker, or to extend the file by writing + * more clusters. next_cluster will contain the value of the + * FAT at last_cluster. + * + * If this is at the head of the cluster chain, then + * last_cluster will be zero and next_cluster will + * be the first cluster in the chain. + */ + if (have == size) { + /* The file is large enough, truncate as needed */ + if (_ao_fat_cluster_valid(next_cluster)) { + DBG("truncate between %08x and %08x\n", last_cluster, next_cluster); + if (last_cluster) + /* + * Otherwise, rewrite the last cluster + * in the chain with a LAST marker + */ + (void) _ao_fat_entry_replace(last_cluster, + AO_FAT_LAST_CLUSTER); + else + /* + * If the file is getting erased, then + * rewrite the directory entry cluster + * value + */ + first_cluster = 0; + + /* Clear the remaining clusters in the chain */ + _ao_fat_free_cluster_chain(next_cluster); + + /* The file system is no longer full (if it was) */ + filesystem_full = 0; + } else { + DBG("unchanged FAT chain\n"); + /* 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; + + /* Set next_free if it has wrapped or wasn't set before */ + 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) == 0) { + next_free = free + 1; + if (next_free >= number_cluster) + next_free = 2; + fsinfo_dirty = 1; + DBG("\tadd cluster. old %08x new %08x\n", last_cluster, free); + 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 + DBG("\tlast cluster %08x\n", last_cluster); + /* Mark the new end of the chain */ + _ao_fat_entry_replace(last_cluster, AO_FAT_LAST_CLUSTER); + } + + DBG("\tfirst cluster %08x\n", first_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 + 1) * 0x20; + cluster_size = (byte_size + bytes_per_cluster - 1) / 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 an open file + */ + +struct ao_file { + struct ao_fat_dirent *dirent; + offset_t offset; + offset_t cluster_offset; + cluster_t cluster; + uint8_t busy; +}; + +#define AO_FAT_NFILE 8 + +static struct ao_fat_dirent ao_file_dirent[AO_FAT_NFILE]; + +static struct ao_fat_dirent * +_ao_fat_file_dirent_alloc(struct ao_fat_dirent *want) +{ + int8_t d; + struct ao_fat_dirent *free = NULL, *dirent; + + for (d = 0; d < AO_FAT_NFILE; d++) { + + dirent = &ao_file_dirent[d]; + /* See if there's another user of this file already */ + if (want && dirent->name[0] != 0) { + if (dirent->entry == want->entry) + return dirent; + } else { + if (!free) { + free = dirent; + if (!want) + break; + } + } + } + if (free && want) + *free = *want; + return free; +} + +static struct ao_file ao_file_table[AO_FAT_NFILE]; + +static int8_t +_ao_fat_fd_alloc(struct ao_fat_dirent *dirent) +{ + int8_t fd; + + for (fd = 0; fd < AO_FAT_NFILE; fd++) + if (!ao_file_table[fd].busy) { + ao_file_table[fd].dirent = _ao_fat_file_dirent_alloc(dirent); + ao_file_table[fd].busy = 1; + ao_file_table[fd].offset = 0; + ao_file_table[fd].cluster_offset = 0; + ao_file_table[fd].cluster = ao_file_table[fd].dirent->cluster; + + return fd; + } + return -AO_FAT_EMFILE; +} + +static void +_ao_fat_fd_free(int8_t fd) +{ + struct ao_file *file = &ao_file_table[fd]; + struct ao_fat_dirent *dirent = file->dirent; + memset(&ao_file_table[fd], '\0', sizeof (struct ao_file)); + + /* Check and see if another ao_file references the same dirent */ + for (fd = 0; fd < AO_FAT_NFILE; fd++) + if (ao_file_table[fd].dirent == dirent) + return; + memset(dirent, '\0', sizeof (struct ao_fat_dirent)); +} + +static struct ao_file * +_ao_fat_fd_to_file(int8_t fd) +{ + struct ao_file *file; + if (fd < 0 || AO_FAT_NFILE <= fd) + return NULL; + + file = &ao_file_table[fd]; + if (!file->busy) + return NULL; + return file; +} + +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; + + /* Reset open file table */ + memset(&ao_file_table, '\0', sizeof (ao_file_table)); + + 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(struct ao_file *file) +{ + cluster_t cluster_offset; + uint32_t sector_offset; + uint16_t sector_index; + cluster_t cluster; + + DBG("current sector offset %d size %d\n", + file->offset, file->dirent->size); + + if (file->offset > file->dirent->size) { + printf ("file offset %d larger than size %d\n", + file->offset, file->dirent->size); + return 0xffffffff; + } + + sector_offset = file->offset >> SECTOR_SHIFT; + + if (!file->cluster || file->offset < file->cluster_offset) { + file->cluster = file->dirent->cluster; + file->cluster_offset = 0; + DBG("\treset to start of file %08x\n", file->cluster); + } + + if (file->cluster_offset + bytes_per_cluster <= file->offset) { + cluster_t cluster_distance; + + cluster_offset = sector_offset / sectors_per_cluster; + + cluster_distance = cluster_offset - file->cluster_offset / bytes_per_cluster; + + DBG("\tseek forward %d clusters\n", cluster_distance); + cluster = _ao_fat_cluster_seek(file->cluster, cluster_distance); + + if (!_ao_fat_cluster_valid(cluster)) { + printf ("invalid cluster %08x\n", cluster); + return 0xffffffff; + } + file->cluster = cluster; + 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", + file->cluster, sector_index, + data_start + (uint32_t) (file->cluster-2) * sectors_per_cluster + sector_index); + return data_start + (uint32_t) (file->cluster-2) * sectors_per_cluster + sector_index; +} + +/* + * _ao_fat_invaldate_cluster_offset + * + * When the file size gets shrunk, invalidate + * any file structures referencing clusters beyond that point + */ + +static void +_ao_fat_invalidate_cluster_offset(struct ao_fat_dirent *dirent) +{ + int8_t fd; + struct ao_file *file; + + for (fd = 0; fd < AO_FAT_NFILE; fd++) { + file = &ao_file_table[fd]; + if (!file->busy) + continue; + if (file->dirent == dirent) { + if (file->cluster_offset >= dirent->size) { + file->cluster_offset = 0; + file->cluster = dirent->cluster; + } + } + } +} + + +/* + * _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(struct ao_file *file, uint32_t size) +{ + uint8_t *dent; + cluster_t first_cluster; + cluster_t have_clusters, need_clusters; + + DBG ("Set size %d\n", size); + if (size == file->dirent->size) { + DBG("\tsize match\n"); + return AO_FAT_SUCCESS; + } + + first_cluster = file->dirent->cluster; + have_clusters = (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 (file->cluster && size > file->cluster_offset) { + cluster_t offset_clusters = (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); + + /* Need one more to account for file->cluster, which we already have */ + next_cluster = _ao_fat_cluster_set_size(file->cluster, extra_clusters + 1); + 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(file->dirent->entry); + if (!dent) { + printf ("dent update failed\n"); + 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, file->dirent->entry, 1); + + file->dirent->size = size; + file->dirent->cluster = first_cluster; + if (have_clusters > need_clusters) + _ao_fat_invalidate_cluster_offset(file->dirent); + 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(struct ao_fat_dirent *dirent, uint8_t *dent, uint16_t entry) +{ + 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 + */ + +static void +_ao_fat_sync(void) +{ + if (_ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) + return; + _ao_fat_flush_fsinfo(); + ao_bufio_flush(); +} + +void +ao_fat_sync(void) +{ + ao_mutex_get(&ao_fat_mutex); + _ao_fat_sync(); + ao_mutex_put(&ao_fat_mutex); +} + +/* + * ao_fat_full + * + * Returns TRUE if the filesystem cannot take + * more data + */ + +int8_t +ao_fat_full(void) +{ + ao_mutex_get(&ao_fat_mutex); + if (_ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) { + ao_mutex_put(&ao_fat_mutex); + return 1; + } + ao_mutex_put(&ao_fat_mutex); + return filesystem_full; +} + +static 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 -AO_FAT_EDIREOF; + + if (dent[0] == AO_FAT_DENT_END) { + _ao_fat_root_put(dent, *entry, 0); + return -AO_FAT_EDIREOF; + } + if (dent[0] != AO_FAT_DENT_EMPTY && (dent[0xb] & 0xf) != 0xf) { + _ao_fat_dirent_init(dirent, dent, *entry); + _ao_fat_root_put(dent, *entry, 0); + (*entry)++; + return AO_FAT_SUCCESS; + } + _ao_fat_root_put(dent, *entry, 0); + (*entry)++; + } +} + +int8_t +ao_fat_readdir(uint16_t *entry, struct ao_fat_dirent *dirent) +{ + int8_t status; + + ao_mutex_get(&ao_fat_mutex); + status = _ao_fat_readdir(entry, dirent); + ao_mutex_put(&ao_fat_mutex); + return status; +} + +/* + * ao_fat_open + * + * Open an existing file. + */ +static int8_t +_ao_fat_open(char name[11], uint8_t mode) +{ + uint16_t entry = 0; + struct ao_fat_dirent dirent; + int8_t status; + + if (_ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) + return -AO_FAT_EIO; + + for (;;) { + status = _ao_fat_readdir(&entry, &dirent); + if (status < 0) { + if (status == -AO_FAT_EDIREOF) + return -AO_FAT_ENOENT; + return status; + } + 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; + return _ao_fat_fd_alloc(&dirent); + } + } + return -AO_FAT_ENOENT; +} + +int8_t +ao_fat_open(char name[11], uint8_t mode) +{ + int8_t status; + + ao_mutex_get(&ao_fat_mutex); + status = _ao_fat_open(name, mode); + ao_mutex_put(&ao_fat_mutex); + return status; +} + +/* + * ao_fat_close + * + * Close the currently open file + */ +static int8_t +_ao_fat_close(int8_t fd) +{ + struct ao_file *file; + + file = _ao_fat_fd_to_file(fd); + if (!file) + return -AO_FAT_EBADF; + + _ao_fat_fd_free(fd); + _ao_fat_sync(); + return AO_FAT_SUCCESS; +} + +int8_t +ao_fat_close(int8_t fd) +{ + int8_t status; + + ao_mutex_get(&ao_fat_mutex); + status = _ao_fat_close(fd); + ao_mutex_put(&ao_fat_mutex); + return status; +} + +/* + * ao_fat_creat + * + * Open and truncate an existing file or + * create a new file + */ + +static int8_t +_ao_fat_creat(char name[11]) +{ + uint16_t entry; + int8_t fd; + int8_t status; + uint8_t *dent; + struct ao_file *file; + + if (_ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) + return -AO_FAT_EIO; + + fd = _ao_fat_open(name, AO_FAT_OPEN_WRITE); + if (fd >= 0) { + file = &ao_file_table[fd]; + status = _ao_fat_set_size(file, 0); + if (status < 0) { + _ao_fat_close(fd); + fd = status; + } + } else { + if (fd == -AO_FAT_ENOENT) { + entry = 0; + for (;;) { + dent = _ao_fat_root_get(entry); + if (!dent) { + + if (_ao_fat_root_extend(entry)) + continue; + fd = -AO_FAT_ENOSPC; + break; + } + if (dent[0] == AO_FAT_DENT_EMPTY || dent[0] == AO_FAT_DENT_END) { + fd = _ao_fat_fd_alloc(NULL); + if (fd < 0) { + _ao_fat_root_put(dent, entry, 0); + break; + } + + file = &ao_file_table[fd]; + /* Initialize the dent */ + _ao_fat_root_init(dent, name, AO_FAT_FILE_REGULAR); + + /* Now initialize the dirent from the dent */ + _ao_fat_dirent_init(file->dirent, dent, entry); + + /* And write the dent to storage */ + _ao_fat_root_put(dent, entry, 1); + + status = -AO_FAT_SUCCESS; + break; + } else { + _ao_fat_root_put(dent, entry, 0); + } + entry++; + } + } + } + return fd; +} + +int8_t +ao_fat_creat(char name[11]) +{ + int8_t status; + + ao_mutex_get(&ao_fat_mutex); + status = _ao_fat_creat(name); + ao_mutex_put(&ao_fat_mutex); + return status; +} + +/* + * ao_fat_map_current + * + * Map the sector pointed at by the current file offset + */ + +static void * +ao_fat_map_current(struct ao_file *file, int len, cluster_offset_t *offsetp, cluster_offset_t *this_time) +{ + cluster_offset_t offset; + sector_t sector; + void *buf; + + offset = file->offset & SECTOR_MASK; + sector = _ao_fat_current_sector(file); + if (sector == 0xffffffff) { + printf ("invalid sector at offset %d\n", file->offset); + return NULL; + } + buf = _ao_fat_sector_get(sector); + if (!buf) + printf ("sector get failed. Sector %d. Partition end %d\n", sector, partition_end); + 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(int8_t fd, void *dst, int len) +{ + uint8_t *dst_b = dst; + cluster_offset_t this_time; + cluster_offset_t offset; + uint8_t *buf; + int ret = 0; + struct ao_file *file; + + ao_mutex_get(&ao_fat_mutex); + file = _ao_fat_fd_to_file(fd); + if (!file) { + ret = -AO_FAT_EBADF; + goto done; + } + + if (file->offset + len > file->dirent->size) + len = file->dirent->size - file->offset; + + if (len < 0) + len = 0; + + while (len) { + buf = ao_fat_map_current(file, len, &offset, &this_time); + if (!buf) { + printf ("map_current failed\n"); + 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; + file->offset = file->offset + this_time; + } +done: + ao_mutex_put(&ao_fat_mutex); + return ret; +} + +/* + * ao_fat_write + * + * Write to the file, extended as necessary + */ +int +ao_fat_write(int8_t fd, void *src, int len) +{ + uint8_t *src_b = src; + cluster_offset_t this_time; + cluster_offset_t offset; + uint8_t *buf; + int ret = 0; + struct ao_file *file; + + ao_mutex_get(&ao_fat_mutex); + file = _ao_fat_fd_to_file(fd); + if (!file) { + ret = -AO_FAT_EBADF; + goto done; + } + + if (file->offset + len > file->dirent->size) { + ret = _ao_fat_set_size(file, file->offset + len); + if (ret < 0) + goto done; + } + + while (len) { + buf = ao_fat_map_current(file, len, &offset, &this_time); + if (!buf) { + printf ("map_current failed\n"); + 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; + file->offset = file->offset + this_time; + } +done: + ao_mutex_put(&ao_fat_mutex); + 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(int8_t fd, int32_t pos, uint8_t whence) +{ + offset_t new_offset; + struct ao_file *file; + int32_t ret; + + ao_mutex_get(&ao_fat_mutex); + file = _ao_fat_fd_to_file(fd); + if (!file) { + ret = -AO_FAT_EBADF; + goto done; + } + + new_offset = file->offset; + 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 = file->dirent->size + pos; + break; + } + ret = file->offset = new_offset; +done: + ao_mutex_put(&ao_fat_mutex); + return ret; +} + +/* + * 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; + int8_t ret; + + ao_mutex_get(&ao_fat_mutex); + if (_ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS) { + ret = -AO_FAT_EIO; + goto done; + } + + 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)) { + ret = -AO_FAT_EISDIR; + goto done; + } + if (!AO_FAT_IS_FILE(dirent.attr)) { + ret = -AO_FAT_EPERM; + goto done; + } + + _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(); + ret = AO_FAT_SUCCESS; + goto done; + } + } + ret = -AO_FAT_ENOENT; +done: + ao_mutex_put(&ao_fat_mutex); + return ret; +} + +int8_t +ao_fat_rename(char old[11], char new[11]) +{ + return -AO_FAT_EIO; +} + +#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; + + ao_mutex_get(&ao_fat_mutex); + 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]); + } + ao_mutex_put(&ao_fat_mutex); +} + +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; + int8_t status; + + while ((status = ao_fat_readdir(&entry, &dirent)) == AO_FAT_SUCCESS) { + 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); + } + if (status != -AO_FAT_EDIREOF) + printf ("readdir failed: %d\n", status); +} + +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(); + } + while (c < 11) + name[c++] = ' '; +} + +static void +ao_fat_dump_cmd(void) +{ + char name[11]; + int8_t fd; + int cnt, i; + char buf[32]; + + ao_fat_parse_name(name); + if (name[0] == '\0') { + ao_cmd_status = ao_cmd_syntax_error; + return; + } + + fd = ao_fat_open(name, AO_FAT_OPEN_READ); + if (fd < 0) { + printf ("Open failed: %d\n", fd); + return; + } + while ((cnt = ao_fat_read(fd, buf, sizeof(buf))) > 0) { + for (i = 0; i < cnt; i++) + putchar(buf[i]); + } + ao_fat_close(fd); +} + +static void +ao_fat_write_cmd(void) +{ + char name[11]; + int8_t fd; + int cnt, i; + char buf[64]; + char c; + int status; + + ao_fat_parse_name(name); + if (name[0] == '\0') { + ao_cmd_status = ao_cmd_syntax_error; + return; + } + + fd = ao_fat_creat(name); + if (fd < 0) { + printf ("Open failed: %d\n", fd); + return; + } + flush(); + while ((c = getchar()) != 4) { + if (c == '\r') c = '\n'; + if (ao_echo()) { + if (c == '\n') putchar ('\r'); + putchar(c); flush(); + } + status = ao_fat_write(fd, &c, 1); + if (status != 1) { + printf ("Write failure %d\n", status); + break; + } + } + ao_fat_close(fd); +} + +static void +put32(uint32_t a) +{ + ao_cmd_put16(a >> 16); + ao_cmd_put16(a); +} + +static void +ao_fat_hexdump_cmd(void) +{ + char name[11]; + int8_t fd; + int cnt, i; + char buf[8]; + uint32_t addr; + + ao_fat_parse_name(name); + if (name[0] == '\0') { + ao_cmd_status = ao_cmd_syntax_error; + return; + } + + fd = ao_fat_open(name, AO_FAT_OPEN_READ); + if (fd < 0) { + printf ("Open failed: %d\n", fd); + return; + } + addr = 0; + while ((cnt = ao_fat_read(fd, buf, sizeof(buf))) > 0) { + put32(addr); + for (i = 0; i < cnt; i++) { + putchar(' '); + ao_cmd_put8(buf[i]); + } + putchar('\n'); + addr += cnt; + } + ao_fat_close(fd); +} + +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_dump_cmd, "D <name>\0Dump FAT file" }, + { ao_fat_write_cmd, "W <name>\0Write FAT file (end with ^D)" }, + { ao_fat_hexdump_cmd, "H <name>\0HEX dump FAT file" }, + { 0, NULL }, +}; + +#endif + +void +ao_fat_init(void) +{ + ao_bufio_init(); + ao_cmd_register(&ao_fat_cmds[0]); +} |