Factor out x86-isms and add cross compile support

This patch cleans up and refactors the Makefiles to better allow new
architectures to be added:
- remove unused Makefile definitions
- import Makefile definitions from top level rather than redefining
- move x86 specific CFLAGS to inside ifeq() blocks
- remove x86 inline asm
- allow $(FORMAT) to be overridden: this is necessary as there exists no
  EFI or PE/COFF aware objcopy for ARM

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

1 files changed, 1 insertions, 9 deletions

diff --git a/netboot.c b/netboot.c
index 5ef53f75..238937d3 100644
--- a/netboot.c
+++ b/netboot.c
@@ -40,15 +40,7 @@
 #include "netboot.h"
 #include "str.h"
 
-static inline unsigned short int __swap16(unsigned short int x)
-{
-        __asm__("xchgb %b0,%h0"
-                : "=q" (x)
-                : "0" (x));
-	return x;
-}
-
-#define ntohs(x) __swap16(x)
+#define ntohs(x) __builtin_bswap16(x)	/* supported both by GCC and clang */
 #define htons(x) ntohs(x)
 
 static EFI_PXE_BASE_CODE *pxe;