/*      $OpenBSD: xxboot.S,v 1.2 2022/12/08 02:11:27 guenther Exp $     */
/*      $NetBSD: xxboot.S,v 1.1 2006/09/01 21:26:19 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(xxboot_start)
        bra     xxboot_start1
         nop
        .balign 4
ENTRY(xxboot_magic)
        .long   0x20031125
boot_params:
        .long   1f - boot_params

        . = xxboot_start + 0x80
xxboot_start1:
        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.2nd_loadaddr, r15    /* new stack pointer */
        mov.l   r4, @-r15
        mov.l   .L.boot1, r0
        jsr     @r0
         mov    r15, r4

        tst     r0, r0
        bf/s    boot_fail
         mov.l  @r15+, r5               /* pass boot sector to boot */

        /* flush cache */
        mov     #0, r4
        mov     #6, r0
        trapa   #0x3f

        mov.l   .L.2nd_loadaddr, r0
        mov.l   .L.boot_params, r4
        jmp     @r0
         nop

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


        .align  2
.L._end:
        .long   _end
.L.__bss_start:
        .long   __bss_start
.L.boot1:
        .long   boot1
.L.2nd_loadaddr:
        .long   LOADADDRESS
.L.boot_params:
        .long   boot_params

        .align  2
.L.errtxt:      .asciz  "Error: "
        .align  2
.L.crlf:        .asciz  "\r\n"


/*
 * int readsects(int dev, uint32_t lba, void *buf, size_t size);
 */
ENTRY(readsects)
        mov     #2, r0
        trapa   #0x3f
        rts
         nop
argerror:
        rts
         mov    #-1, r0

/*
 * void putstr(const char *str);
 */
ENTRY(putstr)
        mov     #32, r0
        trapa   #0x3f
        rts
         nop

/*
 * void putchar(int c);
 */
ENTRY(putchar)
        mov     #31, r0
        trapa   #0x3f
        rts
         nop