Actually, the initrd image should be architecture-independent.

src/arch/i386/image/initrd.c → src/image/initrd.c

  *
  */
 
-#include <initrd.h>
 #include <gpxe/image.h>
+#include <gpxe/initrd.h>
 
 /** Linux initrd image type */
 struct image_type initrd_image_type __image_type ( PROBE_NORMAL ) = {

src/arch/i386/include/initrd.h → src/include/gpxe/initrd.h

-#ifndef _INITRD_H
-#define _INITRD_H
+#ifndef _GPXE_INITRD_H
+#define _GPXE_INITRD_H
 
 /**
  * @file
 #include <gpxe/image.h>
 extern struct image_type initrdimage_image_type __image_type ( PROBE_NORMAL );
 
-#endif /* _INITRD_H */
+#endif /* _GPXE_INITRD_H */