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dump_eax.S revision 1.2 
      1 /*	$NetBSD: dump_eax.S,v 1.2 2008/04/28 20:23:25 martin Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by David Laight.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <machine/asm.h>
     33 
     34 /* This is useful for debugging - although you may need to
     35  * delete some code to fit it in.
     36  * %ds:dump_eax_buff must be somewhere it is safe to write 10 bytes.
     37  */
     38 
     39 ENTRY(dump_eax)
     40 	.code16
     41 	pusha					/* saves bottom 16 bits only! */
     42 	push	%es				/* allow for %es != %ds */
     43 	push	%ds
     44 	pop	%es
     45 	movw	$dump_eax_buff, %si
     46 	mov	%si, %di
     47 	movw	$8, %cx
     48 1:	roll	$4, %eax
     49 	push	%ax
     50 	andb	$0x0f, %al
     51 	addb	$0x30, %al			/* 30..3f - clear AF */
     52 #if 1 /* 5 bytes to generate real hex... */
     53 	daa					/* 30..39, 40..45 */
     54 	addb	$0xc0, %al			/* f0..f9, 00..05 */
     55 	adcb	$0x40, %al			/* 30..39, 41..45 */
     56 #endif
     57 	stosb
     58 	pop	%ax
     59 	loop	1b
     60 	movw	$0x20, %ax			/* space + null */
     61 	stosw
     62 	pop	%es
     63 	jmp	message_1
     64