Added public files
Roughly added all public files. Probably missed some, though.
diff --git a/sys/files.h b/sys/files.h
new file mode 100644
index 0000000..3d7e2c8
--- /dev/null
+++ b/sys/files.h
@@ -0,0 +1,29 @@
+#ifndef LPC_FILES_H_
+#define LPC_FILES_H_ 1
+
+/* Definitions and macros for the various file efuns */
+
+/* Special return values of file_size() and the size part of get_dir().
+ */
+
+#define FSIZE_NOFILE -1 /* File doesn't exist or is not readable */
+#define FSIZE_DIR -2 /* The file is actually a directory */
+
+
+/* Flag values for get_dir().
+ */
+
+#define GETDIR_EMPTY (0) /* return an empty array (not very useful) */
+#define GETDIR_NAMES (0x01) /* return the filenames */
+#define GETDIR_SIZES (0x02) /* return the file sizes */
+#define GETDIR_DATES (0x04) /* return the dates of last modification */
+/* (0x08) unused */
+#define GETDIR_ACCESS (0x40) /* return the dates of last access */
+#define GETDIR_MODES (0x80) /* return the file mode */
+
+#define GETDIR_PATH (0x10) /* with _NAMES: add the path to the filenames */
+#define GETDIR_UNSORTED (0x20) /* return the results unsorted */
+
+#define GETDIR_ALL (0xDF) /* return all */
+
+#endif /* LPC_FILES_H_ */