/*      $NetBSD: srt0.s,v 1.5 2025/08/30 09:27:06 rin Exp $     */

/*-
 * Copyright (C) 1995-1997 Gary Thomas (gdt@linuxppc.org)
 * 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 Gary Thomas.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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_EE  0x8000

        .text

/*
 * This code is loaded by the ROM loader at location 0x3100.
 * Move it to high memory so that it can load the kernel at 0x0000.
 */
#define PEF_LOAD_ADDRESS        0x3100

        .globl  _start
_start:
        mfmsr   3               /* Turn off interrupts */
        li      4,0x3002
        li      4,0
        ori     4,4,MSR_EE
        andc    3,3,4
        mtmsr   3
        bl      whichCPU
        cmpwi   %r3,0
        bne     90f
/* CPU 0 runs here */
/* Relocate code to final resting spot */
        li      3,PEF_LOAD_ADDRESS
        lis     4,_start@h
        ori     4,4,_start@l
        lis     5,edata@h
        ori     5,5,edata@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
0:      lwzu    5,4(3)
        stwu    5,4(4)
        bdnz    0b
        lis     3,start_ldr@h
        ori     3,3,start_ldr@l
        mtlr    3                       /* Easiest way to do an absolute jump */
        blr
start_ldr:      
/* Clear all of BSS */
        lis     3,edata@h
        ori     3,3,edata@l
        lis     4,end@h
        ori     4,4,end@l
        subi    3,3,4
        subi    4,4,4
        li      0,0
50:     stwu    0,4(3)
        cmpw    %r3,%r4
        bne     50b
90:
        bl      main
hang:
        b       hang    

/*
 * end address
 */
        .globl endaddr
endaddr:
        lis     3,end@h
        ori     3,3,end@l
        lis     4,_start@h
        ori     4,4,_start@l
        sub     3,3,4
        blr

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