1 files changed, 45 insertions, 0 deletions
diff --git a/src/arch/i386/include/bits/byteswap.h b/src/arch/i386/include/bits/byteswap.h
new file mode 100644
index 000000000..1bc84fda2
--- /dev/null
+++ b/src/arch/i386/include/bits/byteswap.h
@@ -0,0 +1,45 @@
+#ifndef ETHERBOOT_BITS_BYTESWAP_H
+#define ETHERBOOT_BITS_BYTESWAP_H
+
+static inline uint16_t __i386_bswap_16(uint16_t x)
+{
+	__asm__("xchgb %b0,%h0\n\t"
+		: "=q" (x)
+		: "0" (x));
+	return x;
+}
+
+static inline 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;
+}
+
+
+#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_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)))
+
+
+#endif /* ETHERBOOT_BITS_BYTESWAP_H */