freebsd-dev/sys/amd64/include/endian.h
Peter Wemm afa8862328 Commit MD parts of a loosely functional AMD64 port. This is based on
a heavily stripped down FreeBSD/i386 (brutally stripped down actually) to
attempt to get a stable base to start from.  There is a lot missing still.
Worth noting:
- The kernel runs at 1GB in order to cheat with the pmap code.  pmap uses
  a variation of the PAE code in order to avoid having to worry about 4
  levels of page tables yet.
- It boots in 64 bit "long mode" with a tiny trampoline embedded in the
  i386 loader.  This simplifies locore.s greatly.
- There are still quite a few fragments of i386-specific code that have
  not been translated yet, and some that I cheated and wrote dumb C
  versions of (bcopy etc).
- It has both int 0x80 for syscalls (but using registers for argument
  passing, as is native on the amd64 ABI), and the 'syscall' instruction
  for syscalls.  int 0x80 preserves all registers, 'syscall' does not.
- I have tried to minimize looking at the NetBSD code, except in a couple
  of places (eg: to find which register they use to replace the trashed
  %rcx register in the syscall instruction).  As a result, there is not a
  lot of similarity.  I did look at NetBSD a few times while debugging to
  get some ideas about what I might have done wrong in my first attempt.
2003-05-01 01:05:25 +00:00

130 lines
3.8 KiB
C

/*-
* Copyright (c) 1987, 1991 Regents of the University of California.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
*
* @(#)endian.h 7.8 (Berkeley) 4/3/91
* $FreeBSD$
*/
#ifndef _MACHINE_ENDIAN_H_
#define _MACHINE_ENDIAN_H_
#include <sys/cdefs.h>
#include <sys/_types.h>
/*
* Define the order of 32-bit words in 64-bit words.
*/
#define _QUAD_HIGHWORD 1
#define _QUAD_LOWWORD 0
/*
* Definitions for byte order, according to byte significance from low
* address to high.
*/
#define _LITTLE_ENDIAN 1234 /* LSB first: i386, vax */
#define _BIG_ENDIAN 4321 /* MSB first: 68000, ibm, net */
#define _PDP_ENDIAN 3412 /* LSB first in word, MSW first in long */
#define _BYTE_ORDER _LITTLE_ENDIAN
/*
* Deprecated variants that don't have enough underscores to be useful in more
* strict namespaces.
*/
#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 __word_swap_int(x) \
__extension__ ({ register __uint32_t __X = (x); \
__asm ("rorl $16, %0" : "+r" (__X)); \
__X; })
#define __byte_swap_int(x) \
__extension__ ({ register __uint32_t __X = (x); \
__asm ("bswap %0" : "+r" (__X)); \
__X; })
#define __byte_swap_long(x) \
__extension__ ({ register __uint64_t __X = (x); \
__asm ("bswap %0" : "+r" (__X)); \
__X; })
#define __byte_swap_word(x) \
__extension__ ({ register __uint16_t __X = (x); \
__asm ("xchgb %h0, %b0" : "+Q" (__X)); \
__X; })
static __inline __uint64_t
__bswap64(__uint64_t _x)
{
return (__byte_swap_long(_x));
}
static __inline __uint32_t
__bswap32(__uint32_t _x)
{
return (__byte_swap_int(_x));
}
static __inline __uint16_t
__bswap16(__uint16_t _x)
{
return (__byte_swap_word(_x));
}
#define __htonl(x) __bswap32(x)
#define __htons(x) __bswap16(x)
#define __ntohl(x) __bswap32(x)
#define __ntohs(x) __bswap16(x)
#else /* !__GNUC__ */
/*
* No optimizations are available for this compiler. Fall back to
* non-optimized functions by defining the constant usually used to prevent
* redefinition.
*/
#define _BYTEORDER_FUNC_DEFINED
#endif /* __GNUC__ */
#endif /* !_MACHINE_ENDIAN_H_ */