[x86_64] Add support for compilation as an x86_64 binary

Currently the only supported platform for x86_64 is EFI.

Building an EFI64 gPXE requires a version of gcc that supports
__attribute__((ms_abi)).  This currently means a development build of
gcc; the feature should be present when gcc 4.4 is released.

In the meantime; you can grab a suitable gcc tree from

  git://git.etherboot.org/scm/people/mcb30/gcc/.git

1 files changed, 35 insertions, 0 deletions

diff --git a/src/include/byteswap.h b/src/include/byteswap.h
index 72b5a01d..6c3ced25 100644
--- a/src/include/byteswap.h
+++ b/src/include/byteswap.h
@@ -4,6 +4,41 @@
 #include "endian.h"
 #include "bits/byteswap.h"
 
+#define __bswap_constant_16(x) \
+	((uint16_t)((((uint16_t)(x) & 0x00ff) << 8) | \
+		    (((uint16_t)(x) & 0xff00) >> 8)))
+
+#define __bswap_constant_32(x) \
+	((uint32_t)((((uint32_t)(x) & 0x000000ffU) << 24) | \
+		    (((uint32_t)(x) & 0x0000ff00U) <<  8) | \
+		    (((uint32_t)(x) & 0x00ff0000U) >>  8) | \
+		    (((uint32_t)(x) & 0xff000000U) >> 24)))
+
+#define __bswap_constant_64(x) \
+	((uint64_t)((((uint64_t)(x) & 0x00000000000000ffULL) << 56) | \
+		    (((uint64_t)(x) & 0x000000000000ff00ULL) << 40) | \
+		    (((uint64_t)(x) & 0x0000000000ff0000ULL) << 24) | \
+		    (((uint64_t)(x) & 0x00000000ff000000ULL) <<  8) | \
+		    (((uint64_t)(x) & 0x000000ff00000000ULL) >>  8) | \
+		    (((uint64_t)(x) & 0x0000ff0000000000ULL) >> 24) | \
+		    (((uint64_t)(x) & 0x00ff000000000000ULL) >> 40) | \
+		    (((uint64_t)(x) & 0xff00000000000000ULL) >> 56)))
+
+#define __bswap_16(x) \
+	((uint16_t)(__builtin_constant_p(x) ? \
+	__bswap_constant_16(x) : \
+	__bswap_variable_16(x)))
+
+#define __bswap_32(x) \
+	((uint32_t)(__builtin_constant_p(x) ? \
+	__bswap_constant_32(x) : \
+	__bswap_variable_32(x)))
+
+#define __bswap_64(x) \
+	((uint64_t)(__builtin_constant_p(x) ? \
+	__bswap_constant_64(x) : \
+	__bswap_variable_64(x)))
+
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 #include "little_bswap.h"
 #endif