test: fs: Add test to detect fat type

Ensure that a large FAT12 filesystem and a small FAT16 filesystem are
detected correctly.

Signed-off-by: Christian Taedcke <christian.taedcke@weidmueller.com>

test/py/tests/test_fs/test_fs_fat.py

@@ -0,0 +1,25 @@
+# SPDX-License-Identifier:      GPL-2.0+
+# Copyright (c) 2023 Weidmüller Interface GmbH & Co. KG
+# Author: Christian Taedcke <christian.taedcke@weidmueller.com>
+#
+# U-Boot File System: FAT Test
+
+"""
+This test verifies fat specific file system behaviour.
+"""
+
+import pytest
+import re
+
+@pytest.mark.boardspec('sandbox')
+@pytest.mark.slow
+class TestFsFat(object):
+    def test_fs_fat1(self, u_boot_console, fs_obj_fat):
+        """Test that `fstypes` prints a result which includes `sandbox`."""
+        fs_type,fs_img = fs_obj_fat
+        with u_boot_console.log.section('Test Case 1 - fatinfo'):
+            # Test Case 1 - ls
+            output = u_boot_console.run_command_list([
+                'host bind 0 %s' % fs_img,
+                'fatinfo host 0:0'])
+            assert(re.search('Filesystem: %s' % fs_type.upper(), ''.join(output)))