#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;
+
/* 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)
#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
}
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)
/* 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;
}
/* 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;
* 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);
}
}
* 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);
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
*
mbr = ao_bufio_get(0);
if (!mbr)
- return 0;
+ return AO_FAT_FILESYSTEM_MBR_READ_FAILURE;
/* Check the signature */
if (mbr[0x1fe] != 0x55 || mbr[0x1ff] != 0xaa) {
- printf ("Invalid MBR signature %02x %02x\n",
+ DBG ("Invalid MBR signature %02x %02x\n",
mbr[0x1fe], mbr[0x1ff]);
ao_bufio_put(mbr, 0);
- return 0;
+ return AO_FAT_FILESYSTEM_INVALID_MBR_SIGNATURE;
}
/* Check to see if it's actually a boot block, in which
case 0x0c: /* FAT32 LBA */
break;
default:
- printf ("Invalid partition type %02x\n", partition_type);
+ DBG ("Invalid partition type %02x\n", partition_type);
ao_bufio_put(mbr, 0);
- return 0;
+ return AO_FAT_FILESYSTEM_INVALID_PARTITION_TYPE;
}
partition_start = get_u32(partition+8);
partition_size = get_u32(partition+12);
if (partition_size == 0) {
- printf ("Zero-sized partition\n");
+ DBG ("Zero-sized partition\n");
ao_bufio_put(mbr, 0);
- return 0;
+ return AO_FAT_FILESYSTEM_ZERO_SIZED_PARTITION;
}
}
partition_end = partition_start + partition_size;
- printf ("Partition type %02x start %08x end %08x\n",
- partition_type, partition_start, partition_end);
ao_bufio_put(mbr, 0);
- return 1;
+ return AO_FAT_FILESYSTEM_SUCCESS;
}
static uint8_t
uint32_t data_sectors;
if (!boot)
- return 0;
+ return AO_FAT_FILESYSTEM_BOOT_READ_FAILURE;
/* Check the signature */
if (boot[0x1fe] != 0x55 || boot[0x1ff] != 0xaa) {
- printf ("Invalid BOOT signature %02x %02x\n",
+ DBG ("Invalid BOOT signature %02x %02x\n",
boot[0x1fe], boot[0x1ff]);
ao_fat_sector_put(boot, 0);
- return 0;
+ return AO_FAT_FILESYSTEM_INVALID_BOOT_SIGNATURE;
}
/* Check the sector size */
if (get_u16(boot + 0xb) != SECTOR_SIZE) {
- printf ("Invalid sector size %d\n",
+ DBG ("Invalid sector size %d\n",
get_u16(boot + 0xb));
ao_fat_sector_put(boot, 0);
- return 0;
+ return AO_FAT_FILESYSTEM_INVALID_SECTOR_SIZE;
}
sectors_per_cluster = boot[0xd];
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;
number_cluster = data_sectors / sectors_per_cluster;
- 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);
+ return AO_FAT_FILESYSTEM_SUCCESS;
+}
- printf ("fat start %d\n", fat_start);
- printf ("root start %d\n", root_start);
- printf ("data start %d\n", data_start);
+/*
+ * 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;
- ao_fat_sector_put(boot, 0);
+static uint8_t
+ao_fat_setup(void)
+{
+ if (!ao_filesystem_setup) {
- return 1;
+ 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;
}
-static uint8_t
-ao_fat_setup(void)
+void
+ao_fat_unmount(void)
{
- if (!ao_fat_setup_partition())
- return 0;
- check_bufio("partition setup");
- if (!ao_fat_setup_fs())
- return 0;
- check_bufio("fs setup");
- return 1;
+ ao_filesystem_setup = 0;
}
/*
* 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;
+
+ 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) {
+ 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 = ao_fat_cluster_seek(ao_file_dirent.cluster, cluster_offset);
+ 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;
}
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)
{
-
- if (offset == 0) {
- ao_file_cluster = ao_file_dirent.cluster;
- ao_file_cluster_offset = 0;
- }
- else if (offset < ao_file_cluster_offset ||
- ao_file_cluster_offset + bytes_per_cluster <= offset)
- {
- ao_file_cluster = 0;
- }
+ DBG("Set offset %d\n", offset);
ao_file_offset = 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)
+ DBG ("Set size %d\n", size);
+ if (size == ao_file_dirent.size) {
+ DBG("\tsize match\n");
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;
-
- /* See if there are enough free clusters in the file system */
- need = new_num - old_num;
-
-#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)
+ 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);
- /* 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);
-
+ 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;
}
*
* Initialize a root directory entry
*/
-void
+static void
ao_fat_root_init(uint8_t *dent, char name[11], uint8_t attr)
{
memset(dent, '\0', 0x20);
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
*
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;
{
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_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;
}
} else {
ao_fat_root_put(dent, entry, 0);
}
+ entry++;
}
- if (entry == root_entries)
- status = -AO_FAT_ENOSPC;
}
return status;
}
ao_file_offset = 0;
ao_file_cluster = 0;
ao_file_opened = 0;
- ao_bufio_flush();
+
+ 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
*
int
ao_fat_read(void *dst, int len)
{
- uint8_t *dst_b = dst;
- uint32_t sector;
- uint16_t this_time;
- uint16_t offset;
- uint8_t *buf;
- int ret = 0;
+ 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;
len = 0;
while (len) {
- offset = ao_file_offset & SECTOR_MASK;
- if (offset + len < SECTOR_SIZE)
- this_time = len;
- else
- this_time = SECTOR_SIZE - offset;
-
- sector = ao_fat_current_sector();
- if (sector == 0xffffffff)
- break;
- buf = ao_fat_sector_get(sector);
+ buf = ao_fat_map_current(len, &offset, &this_time);
if (!buf) {
ret = -AO_FAT_EIO;
break;
ao_fat_write(void *src, int len)
{
uint8_t *src_b = src;
- uint32_t sector;
uint16_t this_time;
uint16_t offset;
uint8_t *buf;
}
while (len) {
- offset = ao_file_offset & SECTOR_MASK;
- if (offset + len < SECTOR_SIZE)
- this_time = len;
- else
- this_time = SECTOR_SIZE - offset;
-
- sector = ao_fat_current_sector();
- if (sector == 0xffffffff)
- break;
- buf = ao_fat_sector_get(sector);
+ buf = ao_fat_map_current(len, &offset, &this_time);
if (!buf) {
ret = -AO_FAT_EIO;
break;
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 *dent;
- if (*entry >= root_entries)
- return 0;
+ 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 0;
+ return -AO_FAT_EDIREOF;
}
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;
+ return AO_FAT_SUCCESS;
}
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(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);
+}
- while (ao_fat_readdir(&entry, &dirent)) {
- printf ("%-8.8s.%-3.3s %02x %04x %d\n",
- dirent.name,
- dirent.name + 8,
- dirent.attr,
- 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();
}
+ while (c < 11)
+ name[c++] = ' ';
}
static void
-ao_fat_test(void)
+ao_fat_show_cmd(void)
{
- ao_fat_setup();
- ao_fat_list();
+ 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_test, "F\0Test FAT" },
+ { ao_fat_mbr_cmd, "M\0Show FAT MBR and other info" },
+ { ao_fat_list_cmd, "F\0List FAT directory" },
+ { ao_fat_show_cmd, "S <name>\0Show FAT file" },
+ { ao_fat_write_cmd, "W <name>\0Write FAT file (end with ^D)" },
{ 0, NULL },
};
+#endif
+
void
ao_fat_init(void)
{
projects / fw / altos / blobdiff