cmd: fs: Add command to list supported fs types

Added command "fstypes" to list supported/included filesystems.

Signed-off-by: Niel Fourie <lusus@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Limit to sandbox]
Signed-off-by: Tom Rini <trini@konsulko.com>

cmd/fs.c

@@ -100,3 +100,14 @@ U_BOOT_CMD(
 	"fstype <interface> <dev>:<part> <varname>\n"
 	"- set environment variable to filesystem type\n"
 );
+
+static int do_fstypes_wrapper(struct cmd_tbl *cmdtp, int flag, int argc,
+			      char * const argv[])
+{
+	return do_fs_types(cmdtp, flag, argc, argv);
+}
+
+U_BOOT_CMD(
+	fstypes, 1, 1, do_fstypes_wrapper,
+	"List supported filesystem types", ""
+);

fs/fs.c

@@ -903,3 +903,23 @@ int do_ln(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[],
 
 	return 0;
 }
+
+int do_fs_types(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct fstype_info *drv = fstypes;
+	const int n_ents = ARRAY_SIZE(fstypes);
+	struct fstype_info *entry;
+	int i = 0;
+
+	puts("Supported filesystems");
+	for (entry = drv; entry != drv + n_ents; entry++) {
+		if (entry->fstype != FS_TYPE_ANY) {
+			printf("%c %s", i ? ',' : ':', entry->name);
+			i++;
+		}
+	}
+	if (!i)
+		puts(": <none>");
+	puts("\n");
+	return CMD_RET_SUCCESS;
+}

include/fs.h

@@ -259,4 +259,15 @@ int do_fs_uuid(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[],
  */
 int do_fs_type(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]);
 
+/**
+ * do_fs_types - List supported filesystems.
+ *
+ * @cmdtp: Command information for fstypes
+ * @flag: Command flags (CMD_FLAG_...)
+ * @argc: Number of arguments
+ * @argv: List of arguments
+ * @return result (see enum command_ret_t)
+ */
+int do_fs_types(struct cmd_tbl *cmdtp, int flag, int argc, char * const argv[]);
+
 #endif /* _FS_H */

test/py/tests/test_fs/test_fs_cmd.py

@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2020
+# Niel Fourie, DENX Software Engineering, lusus@denx.de
+
+import pytest
+
+@pytest.mark.boardspec('sandbox')
+@pytest.mark.buildconfigspec('cmd_fs_generic')
+def test_dm_compat(u_boot_console):
+    """Test that `fstypes` prints a result which includes `sandbox`."""
+    output = u_boot_console.run_command('fstypes')
+    assert "Supported filesystems:" in output
+    assert "sandbox" in output