diff -uprN a/linux_spi.c b/linux_spi.c
--- a/flash.h     2015-02-08 16:57:52.000000000 -0500
+++ b/flash.h     2016-01-08 20:09:51.599387507 -0500
@@ -30,6 +30,7 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <stddef.h>
+#include <sys/io.h>
 #include <stdbool.h>
 #if IS_WINDOWS
 #include <windows.h>