1 files changed, 76 insertions, 0 deletions
diff --git a/gpxe/src/arch/i386/include/bits/byteswap.h b/gpxe/src/arch/i386/include/bits/byteswap.h
new file mode 100644
index 00000000..54b93ab9
--- /dev/null
+++ b/gpxe/src/arch/i386/include/bits/byteswap.h
@@ -0,0 +1,76 @@
+#ifndef ETHERBOOT_BITS_BYTESWAP_H
+#define ETHERBOOT_BITS_BYTESWAP_H
+
+static inline __attribute__ ((always_inline, const)) uint16_t
+__i386_bswap_16(uint16_t x)
+{
+	__asm__("xchgb %b0,%h0\n\t"
+		: "=q" (x)
+		: "0" (x));
+	return x;
+}
+
+static inline __attribute__ ((always_inline, const)) uint32_t
+__i386_bswap_32(uint32_t x)
+{
+	__asm__("xchgb %b0,%h0\n\t"
+		"rorl $16,%0\n\t"
+		"xchgb %b0,%h0"
+		: "=q" (x)
+		: "0" (x));
+	return x;
+}
+
+static inline __attribute__ ((always_inline, const)) uint64_t
+__i386_bswap_64(uint64_t x)
+{
+	union {
+		uint64_t qword;
+		uint32_t dword[2]; 
+	} u;
+
+	u.qword = x;
+	u.dword[0] = __i386_bswap_32(u.dword[0]);
+	u.dword[1] = __i386_bswap_32(u.dword[1]);
+	__asm__("xchgl %0,%1"
+		: "=r" ( u.dword[0] ), "=r" ( u.dword[1] )
+		: "0" ( u.dword[0] ), "1" ( u.dword[1] ) );
+	return u.qword;
+}
+
+#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) : \
+	__i386_bswap_16(x)))
+
+#define __bswap_32(x) \
+	((uint32_t)(__builtin_constant_p(x) ? \
+	__bswap_constant_32(x) : \
+	__i386_bswap_32(x)))
+
+#define __bswap_64(x) \
+	((uint64_t)(__builtin_constant_p(x) ? \
+	__bswap_constant_64(x) : \
+	__i386_bswap_64(x)))
+
+#endif /* ETHERBOOT_BITS_BYTESWAP_H */