FAT: implement fat_set_blk_dev(), convert cmd_fat.c

This makes the FAT filesystem API more consistent with other block-based
filesystems. If in the future standard multi-filesystem commands such as
"ls" or "load" are implemented, having FAT work the same way as other
filesystems will be necessary.

Convert cmd_fat.c to the new API, so the code looks more like other files
implementing the same commands for other filesystems.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>

fs/fat/fat.c

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 31042e5..393c378 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -61,44 +61,12 @@
 			cur_part_info.start + block, nr_blocks, buf);
 }
 
-int fat_register_device(block_dev_desc_t * dev_desc, int part_no)
+int fat_set_blk_dev(block_dev_desc_t *dev_desc, disk_partition_t *info)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
 
-	/* First close any currently found FAT filesystem */
-	cur_dev = NULL;
-
-#if (defined(CONFIG_CMD_IDE) || \
-     defined(CONFIG_CMD_SATA) || \
-     defined(CONFIG_CMD_SCSI) || \
-     defined(CONFIG_CMD_USB) || \
-     defined(CONFIG_MMC) || \
-     defined(CONFIG_SYSTEMACE) )
-
-	/* Read the partition table, if present */
-	if (!get_partition_info(dev_desc, part_no, &cur_part_info))
-		cur_dev = dev_desc;
-#endif
-
-	/* Otherwise it might be a superfloppy (whole-disk FAT filesystem) */
-	if (!cur_dev) {
-		if (part_no != 0) {
-			printf("** Partition %d not valid on device %d **\n",
-					part_no, dev_desc->dev);
-			return -1;
-		}
-
-		cur_dev = dev_desc;
-		cur_part_info.start = 0;
-		cur_part_info.size = dev_desc->lba;
-		cur_part_info.blksz = dev_desc->blksz;
-		cur_part_info.name[0] = 0;
-		cur_part_info.type[0] = 0;
-		cur_part_info.bootable = 0;
-#ifdef CONFIG_PARTITION_UUIDS
-		cur_part_info.uuid[0] = 0;
-#endif
-	}
+	cur_dev = dev_desc;
+	cur_part_info = *info;
 
 	/* Make sure it has a valid FAT header */
 	if (disk_read(0, 1, buffer) != 1) {
@@ -122,6 +90,34 @@
 	return -1;
 }
 
+int fat_register_device(block_dev_desc_t *dev_desc, int part_no)
+{
+	disk_partition_t info;
+
+	/* First close any currently found FAT filesystem */
+	cur_dev = NULL;
+
+	/* Read the partition table, if present */
+	if (get_partition_info(dev_desc, part_no, &info)) {
+		if (part_no != 0) {
+			printf("** Partition %d not valid on device %d **\n",
+					part_no, dev_desc->dev);
+			return -1;
+		}
+
+		info.start = 0;
+		info.size = dev_desc->lba;
+		info.blksz = dev_desc->blksz;
+		info.name[0] = 0;
+		info.type[0] = 0;
+		info.bootable = 0;
+#ifdef CONFIG_PARTITION_UUIDS
+		info.uuid[0] = 0;
+#endif
+	}
+
+	return fat_set_blk_dev(dev_desc, &info);
+}
 
 /*
  * Get the first occurence of a directory delimiter ('/' or '\') in a string.