/*      $NetBSD: srt0_pwr.s,v 1.1 2007/12/17 19:09:54 garbled Exp $     */

/*
 * Copyright (C) 1996-1999 Cort Dougan (cort@fsmlasb.com).
 * Copyright (C) 1996-1999 Gary Thomas (gdt@osf.org).
 * Copyright (C) 1996-1999 Paul Mackeras (paulus@linuxcare.com).
 * 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 TooLs GmbH.
 * 4. The name of TooLs GmbH may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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 MSR_DR          (1<<4)
#define MSR_IP          (1<<6)
#define MSR_AL          (1<<7)
#define MSR_ME          (1<<12)

#define HID0_DCI        (1<<10)
#define HID0_ICFI       (1<<11)
#define HID0_DCE        (1<<14)
#define HID0_ICE        (1<<15)

/* when we start, the IPLCB pointer is in r3, and the extended one is in r4 */

        .machine "com"
        .text

        .globl  _start
_start:
        bl      start
start:
        li      2,MSR_ME|MSR_AL /* Establish default MSR value */
        mtmsr   2
        isync
#if 0
/*
        mflr    7
        bl      flush_icache
        mfspr   3,1008
        lis     4,~(HID0_ICE|HID0_DCE)@h
        ori     4,4,~(HID0_ICE|HID0_DCE)@l
        andc    3,3,4
        mtspr   1008,3
        mtlr    7
*/
/*
 * check if we need to relocate ourselves to the link addr or were we
 * loaded there to begin with -- Cort
 */
        lis     4,_start@h
        ori     4,4,_start@l
        mflr    3
        subi    3,3,4           /* we get the nip, not the ip of the branch */
        mr      8,3
        cmpw    3,4
        bne     relocate
        b       start_ldr

/* 
 * no matter where we're loaded, move ourselves to -Ttext address
 */
relocate:
        lis     4,_start@h
        ori     4,4,_start@l
        lis     5,end@h
        ori     5,5,end@l
        addi    5,5,3           /* Round up - just in case */
        sub     5,5,4           /* Compute # longwords to move */
        srwi    5,5,2
        mtctr   5
        subi    3,3,4           /* Set up for loop */
        subi    4,4,4
2:
        lwzu    5,4(3)
        stwu    5,4(4)
        bdnz    2b
        lis     3,start_ldr@h
        ori     3,3,start_ldr@l
        mtlr    3               /* Easiest way to do an absolute jump */
        blr
#endif /* no good */
start_ldr:
        mr      9,1             /* Save old stack pointer */
        lis     1,.stack@h
        ori     1,1,.stack@l
        addi    1,1,4096
        li      2,0x000F
        andc    1,1,2
#if 0
        mr      3,11            /* arg1: residual/board data */
        mr      4,8             /* arg2: loadaddr */
#endif
        bl      boot
hang:
        b       hang

/*
 * Execute
 * run(startsym, endsym, args, bootinfo, entry)
 */
        .globl  run
run:
        mtctr   7                       /* Entry point */
        bctr

/*
 * Flush instruction cache
 */
        .globl flush_icache
flush_icache:
        mflr    5
        bl      flush_dcache
        mfspr   4,1008
        li      4,0
        ori     4,4,HID0_ICE|HID0_ICFI
        or      3,3,4
        mtspr   1008,3
        andc    3,3,4
        ori     3,3,HID0_ICE
        mtspr   1008,3
        mtlr    5
        blr

/*
 * Flush data cache
 */
        .globl flush_dcache
flush_dcache:
        lis     3,0x1000@h
        ori     3,3,0x1000@l
        li      4,1024
        mtctr   4
1:
        lwz     4,0(3)
        addi    3,3,32
        bdnz    1b
        blr

#if 0
/*
 * write LEDS
 */

        .globl led
led:
        mfmsr   5       /* save MSR to r5 */
        lis     7,0xffff
        ori     7,7,~(MSR_DR)
        and     6,5,7
        mtmsr   6
        isync
        
#endif
/*
 * local stack
 */
        .comm   .stack,8192,4