/*      $OpenBSD: srt0.S,v 1.6 2022/12/08 02:11:27 guenther Exp $       */
/*      $NetBSD: boot.S,v 1.1 2006/09/01 21:26:18 uwe Exp $     */

/*-
 * Copyright (c) 2005 NONAKA Kimihiro
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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>

ENTRY(start)
        bra     boot_start1
         nop
        .balign 4
ENTRY(boot_magic)
        .long   0x20041110
ENTRY(boot_params)
        .long   boot_start1 - boot_params

        . = start + 0x80
boot_start1:
        mov     r4, r0
        add     #-4, r0
        mov.l   @(0, r0), r0
        mov.l   .L.boot_magic1, r1
        cmp/eq  r0, r1
        bf      2f
        mov     r4, r0
        mov.l   .L.boot_params_size, r3
        mov.l   @r0, r2
        mov.l   .L.boot_params, r1
        cmp/hi  r3, r2
        bf      1f
        mov     r3, r2
1:      mov.b   @r0+, r3
        mov.b   r3, @r1
        dt      r2
        bf/s    1b
         add    #1, r1
2:
        mov.l   .L._end, r0             /* zero bss */
        mov.l   .L.__bss_start, r1
        sub     r1, r0
        shlr2   r0                      /* _end and __bss_start are aligned */
        mov     #0, r2
1:      mov.l   r2, @r1
        dt      r0
        bf/s    1b
         add    #4, r1

        mov.l   .L.boot, r0
        jsr     @r0
         mov    r5, r4

boot_fail:
        mov     r0, r1
        mova    .L.errtxt, r0
        mov     r0, r4
        mov     #32, r0
        trapa   #0x3f
        mov     r1, r4
        mov     #32, r0
        trapa   #0x3f
        mova    .L.crlf, r0
        mov     r0, r4
        mov     #32, r0
        trapa   #0x3f
99:     bra     99b
         nop


ENTRY(halt)
        mova    .L.pwrctl, r0
        mov     #1, r1
        mov.b   @r1, r0
        rts
         nop

ENTRY(reboot)
ENTRY(_rtt)
        mov     #1, r4                  /* reboot */
        mov     #11, r0
        trapa   #0x3f
        mov.l   .L.start, r0
        jmp     @r0
         nop

/*
 * int readsects(int dev, uint32_t lba, void *buf, size_t size);
 */
ENTRY(readsects)
        mov     #2, r0
        trapa   #0x3f
        rts
         nop

/*
 * void cache_flush(void);
 */
ENTRY(cache_flush)
        /* flush cache */
        mov     #0, r4
        mov     #6, r0
        trapa   #0x3f
        rts
         nop

/*
 * void cache_disable(void);
 */
ENTRY(cache_disable)
        mov     #1, r4
        mov     #6, r0
        trapa   #0x3f
        rts
         nop

        .align  2
.L.boot_magic1:
        .long   0x20031125
.L.boot_params:
        .long   boot_params
.L.boot_params_size:
        .long   boot_start1 - boot_params
.L._end:
        .long   _end
.L.__bss_start:
        .long   __bss_start
.L.boot:
        .long   boot
.L.start:
        .long   0xc0000000
.L.pwrctl:
        .long   0xb0000003

        .align  2
.L.errtxt:      .asciz  ">>BOOT FAILED: "
        .align  2
.L.crlf:        .asciz  "\r\n"