Move fs-filo to filo-fs

Signed-off-by: Thomas Heijligen <src@posteo.de>
diff --git a/src/filo-fs.ads b/src/filo-fs.ads
new file mode 100644
index 0000000..1ed5cf5
--- /dev/null
+++ b/src/filo-fs.ads
@@ -0,0 +1,26 @@
+with Interfaces;
+with Interfaces.C;
+
+use Interfaces.C;
+
+package FILO.FS is
+
+   type Partition_Length is range 0 .. Interfaces.Unsigned_64'Last;
+   subtype Partition_Offset is Partition_Length range 0 .. Partition_Length'Last - 1;
+
+   BLOCK_SIZE : constant := 512;
+   type Block_Offset is range 0 .. Partition_Offset'Last / BLOCK_SIZE;
+
+   type File_Length is range 0 .. int'Last; -- Should be higher, fix FILO first
+   subtype File_Offset is File_Length;
+
+private
+   function Part_Len return Partition_Length;
+
+   function File_Max return File_Length;
+   procedure Set_File_Max (Len : File_Length);
+
+   function File_Pos return File_Offset;
+   procedure Set_File_Pos (Off : File_Offset);
+
+end FILO.FS;