added utility files

memory.x

@@ -0,0 +1,10 @@
+MEMORY
+{
+	FLASH : ORIGIN = 0x00000000, LENGTH = 0x20000 /* 128K */
+	RAM : ORIGIN = 0x10000000, LENGTH = 0x08000 /* 32K */
+}
+
+/* This is where the call stack will be allocated. */
+/* The stack is of the full descending type. */
+/* NOTE Do NOT modify `_stack_start` unless you know what you are doing */
+_stack_start = ORIGIN(RAM) + LENGTH(RAM);