/*      $NetBSD: kickstart.S,v 1.3 2008/04/28 20:23:13 martin Exp $     */

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Ignatios Souvatzis.
 *
 * 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.
 */

#define PPC_CACHESIZE 16384
#define PPC_LINESIZE 32

/*
Memst:  .long   0x08000000
Krnst:  .long   0x082f3400
Krnsz:  .long   0x00100000
 */
        .globl _start
_start:
        bl      L2      /* we start with this address @ 0xfff00100 */
L2:
        lis     13,0xf60000@ha
        li      14,0x08
        stb     14,0xf60000@l(13)
#ifdef DEBUG
        lis     13,0xdff180@h
        ori     13,13,0xdff180@l

        lis     12,1000000@h
        ori     12,12,1000000@l
        mtctr   12
L2a:
        li      14,0x00f
        sth     14,0(13)
        sync
        li      14,0xf0f
        sth     14,0(13)
        sync
        bdnz    L2a
#endif
        mflr    3
        lwz     4,-16(3)
        lwz     5,-12(3)
        lwz     6,-8(3)
        li      7,3
        addi    8,6,3
        cmplw   4,5
        andc    8,8,7
        srwi    9,8,2
        mtctr   9
        bgt     Lb0
/* here: copying downwards and forwards */
        lwz     9,0(5)
        stw     9,0(4)
        bdz     Lflush
Lf1:    lwzu    7,4(5)
        stwu    7,4(4)
        bdnz    Lf1
        b       Lflush

Lb0:    add     4,4,8   /* add the rounded up length */
        add     5,5,8   /* add the rounded up length */
Lb1:    lwzu    7,-4(5)
        stwu    7,-4(4)
        bdnz    Lb1
        
Lflush:
#ifdef DEBUG
        li      14,0xff0
        sth     14,0(13)
        sync
#endif
        li      10,PPC_CACHESIZE/PPC_LINESIZE
        li      11,PPC_LINESIZE
/* dcbst loop */
        mtctr   10
        lwz     12,-8(3)
Lfl1:   dcbst   0,12
        add     12,12,11
        bdnz    Lfl1
        sync            /* and wait for past instructions to finish */
/* icbi loop */
        mtctr   10
        lwz     12,-8(3)
Lfl2:   icbi    0,12
        add     12,12,11
        bdnz    Lfl2
        sync            /* and wait for past instructions to finish */
        isync           /* and flush instruction queue */
Ljump:
#ifdef DEBUG
        li      14,0x0f0
        sth     14,0(13)
        sync
#endif
        lwz     3,-16(3)
        mtlr    3
        blr
/* NOTREACHED */