X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fdrivers%2Fao_fat.c;h=3c72c397e7befeede0fa28d38f56e82bca93b882;hp=7d9bcd810321abcb01b914499da54b128c47d612;hb=0838b6c8797b84cf8df8f92ee20fb6ae79e434d7;hpb=b3d8956df3a3ecb3918b5db4d78b057d68541c33

diff --git a/src/drivers/ao_fat.c b/src/drivers/ao_fat.c
index 7d9bcd81..3c72c397 100644
--- a/src/drivers/ao_fat.c
+++ b/src/drivers/ao_fat.c
@@ -22,6 +22,24 @@
 #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
  */
@@ -268,101 +286,130 @@ ao_fat_cluster_seek(cluster_t cluster, cluster_t distance)
 static cluster_t
 ao_fat_cluster_set_size(cluster_t first_cluster, cluster_t size)
 {
-	cluster_t	clear_cluster = 0;
+	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;
 
-	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;
-		}
+			/* Clear the remaining clusters in the chain */
+			ao_fat_free_cluster_chain(next_cluster);
 
-		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 */
-				;
-			}
+			/* The file system is no longer full (if it was) */
+			filesystem_full = 0;
 		} else {
-			cluster_t	need;
-			cluster_t	free;
+			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;
+		if (filesystem_full)
+			return AO_FAT_BAD_CLUSTER;
 
-			if (next_free < 2 || number_cluster <= next_free) {
-				next_free = 2;
-				fsinfo_dirty = 1;
-			}
+		/* 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;
+		/* 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;
-			}
+#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;
+		}
 
-			/* 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;
+		/* 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
-			/* Mark the new end of the chain */
-			ao_fat_entry_replace(last_cluster, AO_FAT_LAST_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);
 	}
 
-	/* Deallocate clusters off the end of the file */
-	if (ao_fat_cluster_valid(clear_cluster))
-		ao_fat_free_cluster_chain(clear_cluster);
+	DBG("\tfirst cluster %08x\n", first_cluster);
 	return first_cluster;
 }
 
@@ -409,7 +456,7 @@ ao_fat_root_put(uint8_t *root, dirent_t e, uint8_t write)
 /*
  * ao_fat_root_extend
  *
- * On FAT32, make the 
+ * On FAT32, make the root directory at least 'ents' entries long
  */
 static int8_t
 ao_fat_root_extend(dirent_t ents)
@@ -419,8 +466,8 @@ ao_fat_root_extend(dirent_t ents)
 	if (!fat32)
 		return 0;
 	
-	byte_size = ents * 0x20;
-	cluster_size = byte_size / bytes_per_cluster;
+	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;
@@ -440,14 +487,14 @@ ao_fat_setup_partition(void)
 
 	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
@@ -472,24 +519,22 @@ ao_fat_setup_partition(void)
 		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
@@ -499,22 +544,22 @@ ao_fat_setup_fs(void)
 	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];
@@ -552,18 +597,7 @@ ao_fat_setup_fs(void)
 
 	number_cluster = data_sectors / sectors_per_cluster;
 
-	printf ("fat32: %d\n", fat32);
-	printf ("sectors per cluster %d\n", sectors_per_cluster);
-	printf ("reserved sectors %d\n", reserved_sector_count);
-	printf ("number of FATs %d\n", number_fat);
-	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);
-
-	return 1;
+	return AO_FAT_FILESYSTEM_SUCCESS;
 }
 
 /*
@@ -574,8 +608,8 @@ 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_available;
 static uint8_t			ao_filesystem_setup;
+static uint8_t			ao_filesystem_status;
 
 static uint8_t
 ao_fat_setup(void)
@@ -597,13 +631,20 @@ ao_fat_setup(void)
 		memset(&ao_file_dirent, '\0', sizeof (ao_file_dirent));
 
 		ao_file_offset = ao_file_cluster_offset = ao_file_cluster = ao_file_opened = 0;
-		if (!ao_fat_setup_partition())
-			return 0;
-		if (!ao_fat_setup_fs())
-			return 0;
-		ao_filesystem_available = 1;
+		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_available;
+	return ao_filesystem_status;
+}
+
+void
+ao_fat_unmount(void)
+{
+	ao_filesystem_setup = 0;
 }
 
 /*
@@ -618,6 +659,9 @@ ao_fat_current_sector(void)
 	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;
 
@@ -626,6 +670,7 @@ ao_fat_current_sector(void)
 	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) {
@@ -635,6 +680,7 @@ ao_fat_current_sector(void)
 
 		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))
@@ -644,12 +690,16 @@ ao_fat_current_sector(void)
 	}
 
 	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;
 }
 
@@ -666,23 +716,30 @@ ao_fat_set_size(uint32_t size)
 	cluster_t	first_cluster;
 	cluster_t	have_clusters, need_clusters;
 
-	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;
+	}
 
 	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)
@@ -690,6 +747,7 @@ ao_fat_set_size(uint32_t size)
 		}
 	}
 
+	DBG ("\tupdate directory size\n");
 	/* Update the directory entry */
 	dent = ao_fat_root_get(ao_file_dirent.entry);
 	if (!dent)
@@ -702,6 +760,7 @@ ao_fat_set_size(uint32_t size)
 
 	ao_file_dirent.size = size;
 	ao_file_dirent.cluster = first_cluster;
+	DBG ("set size done\n");
 	return AO_FAT_SUCCESS;
 }
 
@@ -796,7 +855,7 @@ ao_fat_flush_fsinfo(void)
 void
 ao_fat_sync(void)
 {
-	if (!ao_fat_setup())
+	if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS)
 		return;
 	ao_fat_flush_fsinfo();
 	ao_bufio_flush();
@@ -812,8 +871,8 @@ ao_fat_sync(void)
 int8_t
 ao_fat_full(void)
 {
-	if (!ao_fat_setup())
-		return -AO_FAT_EIO;
+	if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS)
+		return 1;
 	return filesystem_full;
 }
 
@@ -828,7 +887,7 @@ ao_fat_open(char name[11], uint8_t mode)
 	uint16_t		entry = 0;
 	struct ao_fat_dirent	dirent;
 
-	if (!ao_fat_setup())
+	if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS)
 		return -AO_FAT_EIO;
 
 	if (ao_file_opened)
@@ -864,7 +923,7 @@ ao_fat_creat(char name[11])
 	int8_t		status;
 	uint8_t		*dent;
 
-	if (!ao_fat_setup())
+	if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS)
 		return -AO_FAT_EIO;
 
 	if (ao_file_opened)
@@ -925,6 +984,32 @@ ao_fat_close(void)
 	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
  *
@@ -933,12 +1018,11 @@ ao_fat_close(void)
 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;
@@ -950,16 +1034,7 @@ ao_fat_read(void *dst, int len)
 		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;
@@ -984,7 +1059,6 @@ int
 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;
@@ -1000,16 +1074,7 @@ ao_fat_write(void *src, int len)
 	}
 
 	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;
@@ -1069,8 +1134,9 @@ ao_fat_unlink(char name[11])
 	uint16_t		entry = 0;
 	struct ao_fat_dirent	dirent;
 
-	if (!ao_fat_setup())
+	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;
@@ -1114,49 +1180,205 @@ ao_fat_readdir(uint16_t *entry, struct ao_fat_dirent *dirent)
 {
 	uint8_t	*dent;
 
-	if (!ao_fat_setup())
+	if (ao_fat_setup() != AO_FAT_FILESYSTEM_SUCCESS)
 		return -AO_FAT_EIO;
+
 	for (;;) {
 		dent = ao_fat_root_get(*entry);
 		if (!dent)
-			return 0;
+			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_list(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;
+	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_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_list,	"F\0List 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)
 {