We don't actually have a stdio.h header file. Our printf() functions are

defined in vsprintf.h.  (This may change, since vsprintf.h is a
non-standard name, but for now it's the one to use.)

There should be no need to include vsprintf.h just for DBG() statements,
since include/compiler.h forces it in for a debug build anyway.

src/arch/i386/firmware/pcbios/hidemem.c

@@ -15,7 +15,6 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include <stdio.h>
 #include <realmode.h>
 #include <biosint.h>