freebsd-dev/sys/libkern/alpha/byte_swap_2.S

/* $FreeBSD$ */
/*	$NetBSD: byte_swap_2.S,v 1.2 1996/10/17 03:08:08 cgd Exp $	*/

/*-
 * Copyright (c) 1996 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#include <machine/asm.h>

#ifndef NAME
#error NAME not defined
#endif

/*
 * Byte-swap a 2-byte quantity.  (Convert 0x0123 to 0x2301.)
 *
 * Argument is an unsigned 2-byte integer (u_int16_t).
 */
LEAF(NAME, 1)			/* a0 contains 0x0123 */
	extbl	a0, 0, t0	/* t0 = 0x  23 */
	extbl	a0, 1, t1	/* t1 = 0x  01 */
	sll	t0, 8, t0	/* t1 = 0x23   */
	or	t0, t1, v0	/* v0 = 0x2301 */
	RET
END(NAME)
Add $FreeBSD$ 2000-05-01 20:32:07 +00:00			`/* $FreeBSD$ */`
Add initial support for the FreeBSD/alpha kernel. This is very much a work in progress and has never booted a real machine. Initial development and testing was done using SimOS (see http://simos.stanford.edu for details). On the SimOS simulator, this port successfully reaches single-user mode and has been tested with loads as high as one copy of /bin/ls :-). Obtained from: partly from NetBSD/alpha 1998-06-10 10:57:29 +00:00			`/* $NetBSD: byte_swap_2.S,v 1.2 1996/10/17 03:08:08 cgd Exp $ */`

/* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-07 00:24:33 +00:00			`/*-`
Add initial support for the FreeBSD/alpha kernel. This is very much a work in progress and has never booted a real machine. Initial development and testing was done using SimOS (see http://simos.stanford.edu for details). On the SimOS simulator, this port successfully reaches single-user mode and has been tested with loads as high as one copy of /bin/ls :-). Obtained from: partly from NetBSD/alpha 1998-06-10 10:57:29 +00:00			`* Copyright (c) 1996 Carnegie-Mellon University.`
			`* All rights reserved.`
			`*`
			`* Author: Chris G. Demetriou`
			`*`
			`* Permission to use, copy, modify and distribute this software and`
			`* its documentation is hereby granted, provided that both the copyright`
			`* notice and this permission notice appear in all copies of the`
			`* software, derivative works or modified versions, and any portions`
			`* thereof, and that both notices appear in supporting documentation.`
			`*`
			`* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"`
			`* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND`
			`* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.`
			`*`
			`* Carnegie Mellon requests users of this software to return to`
			`*`
			`* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU`
			`* School of Computer Science`
			`* Carnegie Mellon University`
			`* Pittsburgh PA 15213-3890`
			`*`
			`* any improvements or extensions that they make and grant Carnegie the`
			`* rights to redistribute these changes.`
			`*/`

			`#include <machine/asm.h>`

Add the following functions/macros to support byte order conversions and device drivers for bus system with other endinesses than the CPU (using interfaces compatible to NetBSD): - bwap16() and bswap32(). These have optimized implementations on some architectures; for those that don't, there exist generic implementations. - macros to convert from a certain byte order to host byte order and vice versa, using a naming scheme like le16toh(), htole16(). These are implemented using the bswap functions. - stream bus space access functions, which do not perform a byte order conversion (while the normal access functions would if the bus endianess differs from the CPU endianess). htons(), htonl(), ntohs() and ntohl() are implemented using the new functions above for kernel usage. None of the above interfaces is currently exported to user land. Make use of the new functions in a few places where local implementations of the same functionality existed. Reviewed by: mike, bde Tested on alpha by: mike 2002-02-27 17:16:18 +00:00			`#ifndef NAME`
			`#error NAME not defined`
Add initial support for the FreeBSD/alpha kernel. This is very much a work in progress and has never booted a real machine. Initial development and testing was done using SimOS (see http://simos.stanford.edu for details). On the SimOS simulator, this port successfully reaches single-user mode and has been tested with loads as high as one copy of /bin/ls :-). Obtained from: partly from NetBSD/alpha 1998-06-10 10:57:29 +00:00			`#endif`

			`/*`
			`* Byte-swap a 2-byte quantity. (Convert 0x0123 to 0x2301.)`
			`*`
			`* Argument is an unsigned 2-byte integer (u_int16_t).`
			`*/`
			`LEAF(NAME, 1) /* a0 contains 0x0123 */`
			`extbl a0, 0, t0 /* t0 = 0x 23 */`
			`extbl a0, 1, t1 /* t1 = 0x 01 */`
			`sll t0, 8, t0 /* t1 = 0x23 */`
			`or t0, t1, v0 /* v0 = 0x2301 */`
			`RET`
			`END(NAME)`