fs: add filesystem switch libary, implement ls and fsload commands

Implement "ls" and "fsload" commands that act like {fat,ext2}{ls,load},
and transparently handle either file-system. This scheme could easily be
extended to other filesystem types; I only didn't do it for zfs because
I don't have any filesystems of that type to test with.

Replace the implementation of {fat,ext[24]}{ls,load} with this new code
too.

Signed-off-by: Stephen Warren <swarren@nvidia.com>

2 files changed, 65 insertions, 3 deletions

diff --git a/include/ext_common.h b/include/ext_common.h
index ce73857..86373a6 100644
--- a/include/ext_common.h
+++ b/include/ext_common.h
@@ -195,7 +195,4 @@ int do_ext4_load(cmd_tbl_t *cmdtp, int flag, int argc,
 int do_ext4_ls(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
 int do_ext4_write(cmd_tbl_t *cmdtp, int flag, int argc,
 				char *const argv[]);
-int do_ext_load(cmd_tbl_t *cmdtp, int flag, int argc,
-					char *const argv[]);
-int do_ext_ls(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]);
 #endif
diff --git a/include/fs.h b/include/fs.h
new file mode 100644
index 0000000..f396d84
--- /dev/null
+++ b/include/fs.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef _FS_H
+#define _FS_H
+
+#include <common.h>
+
+#define FS_TYPE_ANY	0
+#define FS_TYPE_FAT	1
+#define FS_TYPE_EXT	2
+
+/*
+ * Tell the fs layer which block device an partition to use for future
+ * commands. This also internally identifies the filesystem that is present
+ * within the partition. The identification process may be limited to a
+ * specific filesystem type by passing FS_* in the fstype parameter.
+ *
+ * Returns 0 on success.
+ * Returns non-zero if there is an error accessing the disk or partition, or
+ * no known filesystem type could be recognized on it.
+ */
+int fs_set_blk_dev(const char *ifname, const char *dev_part_str, int fstype);
+
+/*
+ * Print the list of files on the partition previously set by fs_set_blk_dev(),
+ * in directory "dirname".
+ *
+ * Returns 0 on success. Returns non-zero on error.
+ */
+int fs_ls(const char *dirname);
+
+/*
+ * Read file "filename" from the partition previously set by fs_set_blk_dev(),
+ * to address "addr", starting at byte offset "offset", and reading "len"
+ * bytes. "offset" may be 0 to read from the start of the file. "len" may be
+ * 0 to read the entire file. Note that not all filesystem types support
+ * either/both offset!=0 or len!=0.
+ *
+ * Returns number of bytes read on success. Returns <= 0 on error.
+ */
+int fs_read(const char *filename, ulong addr, int offset, int len);
+
+/*
+ * Common implementation for various filesystem commands, optionally limited
+ * to a specific filesystem type via the fstype parameter.
+ */
+int do_fsload(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
+		int fstype);
+int do_ls(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
+		int fstype);
+
+#endif /* _FS_H */