/*      $NetBSD: start.S,v 1.2 2008/04/28 20:23:19 martin Exp $ */

/*-
 * Copyright (c) 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by UCHIYAMA Yasushi.
 *
 * 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.
 */

#include <mips/regdef.h>

        .set    noreorder
        .set    mips3
        .align  2
        .text
/*
 * Entry point.
 */
        .globl  start
start:
        nop
        nop
        nop
        nop
        la      sp, _ftext

        mfc0    t0, $12
        lui     t1, 0x0040      /* BEV : use IPL's exception vector. */
        and     t0, t0, t1
        mtc0    t0, $12
        nop
        la      t0, main
        move    a1, v0
        jr      t0
         move   a2, v1          /* v1 = mainfo */
1:      b       1b
         nop
        /* NOTREACHED */

#if 0 /* ROM putc test */
        li      a0, 50          /* x-pos */
2:      li      a2, 90          /* 'Z' */
        lui     v0, 0xbfc0
        ori     v0, 0xff60
        li      a1, 50          /* y-pos */
        jal     v0
         nop
        b       2b
         addiu  a0, a0, 12
        /* NOTREACHED */
#endif
#if 0 /* Frame buffer (TLB kseg2 mapped by IPL) test */
        move    a3, zero
        xori    a3, a3, 0x00
3:      sll     v0, a3, 0x18
        sra     a2, v0, 0x18
        lui     a0, 0xf000
        move    v1, zero
        lui     a1, 0x1
        ori     a1, a1, 0xffff
2:      sb      a2, 0(a0)
        addiu   v1, v1, 1
        slt     v0, a1, v1
        addiu   a0, a0, 1
        beqz    v0, 2b
         nop
        xori    a3, a3, 0xff
        j       3b
         nop
        /* NOTREACHED */
#endif

/*
 * void tlb_read(int index, void *)
 */
        .global tlb_read
        .ent    tlb_read
tlb_read:
        mtc0    a0, $0          /* Index Register */
        nop; nop; nop; nop;
        tlbr
        nop; nop; nop; nop;
        mfc0    t0, $5          /* PageMask */
        nop; nop; nop; nop;
        mfc0    t1, $10         /* EntryHi */
        nop; nop; nop; nop;
        mfc0    t2, $2          /* EntryLo0 */
        nop; nop; nop; nop;
        mfc0    t3, $3          /* EntryLo1 */
        nop; nop; nop; nop;
        sw      t0,  0(a1)
        sw      t1,  4(a1)
        sw      t2,  8(a1)
        sw      t3, 12(a1)
        jr      ra
         nop
        .end    tlb_read