auto import from //depot/cupcake/@135843
diff --git a/libc/include/sys/endian.h b/libc/include/sys/endian.h
new file mode 100644
index 0000000..00f4839
--- /dev/null
+++ b/libc/include/sys/endian.h
@@ -0,0 +1,273 @@
+/* $OpenBSD: endian.h,v 1.17 2006/01/06 18:53:05 millert Exp $ */
+
+/*-
+ * Copyright (c) 1997 Niklas Hallqvist. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Generic definitions for little- and big-endian systems. Other endianesses
+ * has to be dealt with in the specific machine/endian.h file for that port.
+ *
+ * This file is meant to be included from a little- or big-endian port's
+ * machine/endian.h after setting _BYTE_ORDER to either 1234 for little endian
+ * or 4321 for big..
+ */
+
+#ifndef _SYS_ENDIAN_H_
+#define _SYS_ENDIAN_H_
+
+#include <sys/cdefs.h>
+#include <machine/_types.h>
+
+#define _LITTLE_ENDIAN 1234
+#define _BIG_ENDIAN 4321
+#define _PDP_ENDIAN 3412
+
+#if __BSD_VISIBLE
+#define LITTLE_ENDIAN _LITTLE_ENDIAN
+#define BIG_ENDIAN _BIG_ENDIAN
+#define PDP_ENDIAN _PDP_ENDIAN
+#define BYTE_ORDER _BYTE_ORDER
+#endif
+
+#ifdef __GNUC__
+
+#define __swap16gen(x) __statement({ \
+ __uint16_t __swap16gen_x = (x); \
+ \
+ (__uint16_t)((__swap16gen_x & 0xff) << 8 | \
+ (__swap16gen_x & 0xff00) >> 8); \
+})
+
+#define __swap32gen(x) __statement({ \
+ __uint32_t __swap32gen_x = (x); \
+ \
+ (__uint32_t)((__swap32gen_x & 0xff) << 24 | \
+ (__swap32gen_x & 0xff00) << 8 | \
+ (__swap32gen_x & 0xff0000) >> 8 | \
+ (__swap32gen_x & 0xff000000) >> 24); \
+})
+
+#define __swap64gen(x) __statement({ \
+ __uint64_t __swap64gen_x = (x); \
+ \
+ (__uint64_t)((__swap64gen_x & 0xff) << 56 | \
+ (__swap64gen_x & 0xff00ULL) << 40 | \
+ (__swap64gen_x & 0xff0000ULL) << 24 | \
+ (__swap64gen_x & 0xff000000ULL) << 8 | \
+ (__swap64gen_x & 0xff00000000ULL) >> 8 | \
+ (__swap64gen_x & 0xff0000000000ULL) >> 24 | \
+ (__swap64gen_x & 0xff000000000000ULL) >> 40 | \
+ (__swap64gen_x & 0xff00000000000000ULL) >> 56); \
+})
+
+#else /* __GNUC__ */
+
+/* Note that these macros evaluate their arguments several times. */
+#define __swap16gen(x) \
+ (__uint16_t)(((__uint16_t)(x) & 0xff) << 8 | ((__uint16_t)(x) & 0xff00) >> 8)
+
+#define __swap32gen(x) \
+ (__uint32_t)(((__uint32_t)(x) & 0xff) << 24 | \
+ ((__uint32_t)(x) & 0xff00) << 8 | ((__uint32_t)(x) & 0xff0000) >> 8 |\
+ ((__uint32_t)(x) & 0xff000000) >> 24)
+
+#define __swap64gen(x) \
+ (__uint64_t)((((__uint64_t)(x) & 0xff) << 56) | \
+ ((__uint64_t)(x) & 0xff00ULL) << 40 | \
+ ((__uint64_t)(x) & 0xff0000ULL) << 24 | \
+ ((__uint64_t)(x) & 0xff000000ULL) << 8 | \
+ ((__uint64_t)(x) & 0xff00000000ULL) >> 8 | \
+ ((__uint64_t)(x) & 0xff0000000000ULL) >> 24 | \
+ ((__uint64_t)(x) & 0xff000000000000ULL) >> 40 | \
+ ((__uint64_t)(x) & 0xff00000000000000ULL) >> 56)
+
+#endif /* __GNUC__ */
+
+/*
+ * Define MD_SWAP if you provide swap{16,32}md functions/macros that are
+ * optimized for your architecture, These will be used for swap{16,32}
+ * unless the argument is a constant and we are using GCC, where we can
+ * take advantage of the CSE phase much better by using the generic version.
+ */
+#ifdef MD_SWAP
+#if __GNUC__
+
+#define __swap16(x) __statement({ \
+ __uint16_t __swap16_x = (x); \
+ \
+ __builtin_constant_p(x) ? __swap16gen(__swap16_x) : \
+ __swap16md(__swap16_x); \
+})
+
+#define __swap32(x) __statement({ \
+ __uint32_t __swap32_x = (x); \
+ \
+ __builtin_constant_p(x) ? __swap32gen(__swap32_x) : \
+ __swap32md(__swap32_x); \
+})
+
+#define __swap64(x) __statement({ \
+ __uint64_t __swap64_x = (x); \
+ \
+ __builtin_constant_p(x) ? __swap64gen(__swap64_x) : \
+ __swap64md(__swap64_x); \
+})
+
+#endif /* __GNUC__ */
+
+#else /* MD_SWAP */
+#define __swap16 __swap16gen
+#define __swap32 __swap32gen
+#define __swap64 __swap64gen
+#endif /* MD_SWAP */
+
+#define __swap16_multi(v, n) do { \
+ __size_t __swap16_multi_n = (n); \
+ __uint16_t *__swap16_multi_v = (v); \
+ \
+ while (__swap16_multi_n) { \
+ *__swap16_multi_v = swap16(*__swap16_multi_v); \
+ __swap16_multi_v++; \
+ __swap16_multi_n--; \
+ } \
+} while (0)
+
+#if __BSD_VISIBLE
+#define swap16 __swap16
+#define swap32 __swap32
+#define swap64 __swap64
+#define swap16_multi __swap16_multi
+
+__BEGIN_DECLS
+__uint64_t htobe64(__uint64_t);
+__uint32_t htobe32(__uint32_t);
+__uint16_t htobe16(__uint16_t);
+__uint64_t betoh64(__uint64_t);
+__uint32_t betoh32(__uint32_t);
+__uint16_t betoh16(__uint16_t);
+
+__uint64_t htole64(__uint64_t);
+__uint32_t htole32(__uint32_t);
+__uint16_t htole16(__uint16_t);
+__uint64_t letoh64(__uint64_t);
+__uint32_t letoh32(__uint32_t);
+__uint16_t letoh16(__uint16_t);
+__END_DECLS
+#endif /* __BSD_VISIBLE */
+
+#if _BYTE_ORDER == _LITTLE_ENDIAN
+
+/* Can be overridden by machine/endian.h before inclusion of this file. */
+#ifndef _QUAD_HIGHWORD
+#define _QUAD_HIGHWORD 1
+#endif
+#ifndef _QUAD_LOWWORD
+#define _QUAD_LOWWORD 0
+#endif
+
+#if __BSD_VISIBLE
+#define htobe16 __swap16
+#define htobe32 __swap32
+#define htobe64 __swap64
+#define betoh16 __swap16
+#define betoh32 __swap32
+#define betoh64 __swap64
+
+#define htole16(x) (x)
+#define htole32(x) (x)
+#define htole64(x) (x)
+#define letoh16(x) (x)
+#define letoh32(x) (x)
+#define letoh64(x) (x)
+#endif /* __BSD_VISIBLE */
+
+#define htons(x) __swap16(x)
+#define htonl(x) __swap32(x)
+#define ntohs(x) __swap16(x)
+#define ntohl(x) __swap32(x)
+
+/* Bionic additions */
+#define ntohq(x) __swap64(x)
+#define htonq(x) __swap64(x)
+
+#define __LITTLE_ENDIAN_BITFIELD
+
+#endif /* _BYTE_ORDER */
+
+#if _BYTE_ORDER == _BIG_ENDIAN
+
+/* Can be overridden by machine/endian.h before inclusion of this file. */
+#ifndef _QUAD_HIGHWORD
+#define _QUAD_HIGHWORD 0
+#endif
+#ifndef _QUAD_LOWWORD
+#define _QUAD_LOWWORD 1
+#endif
+
+#if __BSD_VISIBLE
+#define htole16 __swap16
+#define htole32 __swap32
+#define htole64 __swap64
+#define letoh16 __swap16
+#define letoh32 __swap32
+#define letoh64 __swap64
+
+#define htobe16(x) (x)
+#define htobe32(x) (x)
+#define htobe64(x) (x)
+#define betoh16(x) (x)
+#define betoh32(x) (x)
+#define betoh64(x) (x)
+#endif /* __BSD_VISIBLE */
+
+#define htons(x) (x)
+#define htonl(x) (x)
+#define ntohs(x) (x)
+#define ntohl(x) (x)
+
+/* Bionic additions */
+#define ntohq(x) (x)
+#define htonq(x) (x)
+
+#define __BIG_ENDIAN_BITFIELD
+
+#endif /* _BYTE_ORDER */
+
+#if __BSD_VISIBLE
+#define NTOHL(x) (x) = ntohl((u_int32_t)(x))
+#define NTOHS(x) (x) = ntohs((u_int16_t)(x))
+#define HTONL(x) (x) = htonl((u_int32_t)(x))
+#define HTONS(x) (x) = htons((u_int16_t)(x))
+#endif
+
+
+#define __BYTE_ORDER _BYTE_ORDER
+#ifndef __LITTLE_ENDIAN
+#define __LITTLE_ENDIAN _LITTLE_ENDIAN
+#endif
+#ifndef __BIG_ENDIAN
+#define __BIG_ENDIAN _BIG_ENDIAN
+#endif
+
+#endif /* _SYS_ENDIAN_H_ */