/*      $NetBSD: pvcopy.S,v 1.2 2008/04/28 20:23:25 martin Exp $        */

/*-
* Copyright (c) 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by David Laight.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/

#include <machine/asm.h>

/*
* Routines to copy to/from absolute virtual addresses.
* Needed because the boot code runs with %ds having a 64k offset
* whereas Unix runs with a zero offset.
*
* These routines are optimised for code space, not execution speed.
*/

/*
* pbzero(void *dst, int cnt)
*      zero absolute virtual memory
*/
ENTRY(pbzero)
       .code32
       push    %edi
       push    %es
       mov     12(%esp),%edi
       mov     16(%esp),%ecx

       mov     $flatdataseg, %ax       /* selector with offset == 0 */
       mov     %ax, %es
       xor     %eax,%eax

       cld
       rep
       stosb

       pop     %es
       pop     %edi
       ret

/*
* vpbcopy(const void *src, void *dst, int cnt)
*      Copy to absolute virtual address
*/
ENTRY(vpbcopy)
       .code32
       push    %esi
       push    %edi
       push    %es
       mov     16(%esp),%esi
       mov     20(%esp),%edi
       mov     24(%esp),%ecx

       mov     $flatdataseg, %ax       /* selector with offset == 0 */
       mov     %ax, %es
       xor     %eax,%eax

       cld
       rep
       movsb

       popl    %es
       popl    %edi
       popl    %esi
       ret

/*
* pvbcopy(const void *src, void *dst, int cnt)
*      Copy from absolute virtual address
*/
ENTRY(pvbcopy)
       .code32
       push    %esi
       push    %edi
       push    %ds
       mov     16(%esp),%esi
       mov     20(%esp),%edi
       mov     24(%esp),%ecx

       mov     $flatdataseg, %ax       /* selector with offset == 0 */
       mov     %ax, %ds
       xor     %eax,%eax

       cld
       rep
       movsb

       popl    %ds
       popl    %edi
       popl    %esi
       ret

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