fs/fat: implement fsuuid command

The FAT file system does not have a UUID but a 4 byte volume ID.
Let the fsuuid command show it in XXXX-XXXX format.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index c9742d5..157dad6 100644 (file)
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -1377,3 +1377,21 @@ void fat_closedir(struct fs_dir_stream *dirs)
 void fat_close(void)
 {
 }
+
+int fat_uuid(char *uuid_str)
+{
+       boot_sector bs;
+       volume_info volinfo;
+       int fatsize;
+       int ret;
+       u8 *id;
+
+       ret = read_bootsectandvi(&bs, &volinfo, &fatsize);
+       if (ret)
+               return ret;
+
+       id = volinfo.volume_id;
+       sprintf(uuid_str, "%02X%02X-%02X%02X", id[3], id[2], id[1], id[0]);
+
+       return 0;
+}

diff --git a/fs/fs.c b/fs/fs.c
index 7a40206..5e80648 100644 (file)
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -194,7 +194,7 @@ static struct fstype_info fstypes[] = {
                .unlink = fs_unlink_unsupported,
                .mkdir = fs_mkdir_unsupported,
 #endif
-               .uuid = fs_uuid_unsupported,
+               .uuid = fat_uuid,
                .opendir = fat_opendir,
                .readdir = fat_readdir,
                .closedir = fat_closedir,

diff --git a/include/fat.h b/include/fat.h
index 8cae283..b9f273f 100644 (file)
--- a/include/fat.h
+++ b/include/fat.h
@@ -212,4 +212,16 @@ int fat_unlink(const char *filename);
 int fat_mkdir(const char *dirname);
 void fat_close(void);
 void *fat_next_cluster(fat_itr *itr, unsigned int *nbytes);
+
+/**
+ * fat_uuid() - get FAT volume ID
+ *
+ * The FAT volume ID returned in @uuid_str as hexadecimal number in XXXX-XXXX
+ * format.
+ *
+ * @uuid_str:  caller allocated buffer of at least 10 bytes for the volume ID
+ * Return:     0 on success
+ */
+int fat_uuid(char *uuid_str);
+
 #endif /* _FAT_H_ */