/*      $NetBSD: iris_start.S,v 1.1 2019/01/12 16:44:47 tsutsui Exp $   */

/*
 * Copyright (c) 2018 Naruaki Etomi
 * 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 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.
 */

/*
 * Silicon Graphics "IRIS" series MIPS processors machine bootloader.
 */

#include <mips/asm.h>
#include <mips/cpuregs.h>

        .globl  start
start:
        .set    noreorder
#ifdef __GP_SUPPORT__
        la      gp, _C_LABEL(_gp)
#endif
        /*
         * We assume the bootprom isn't expecting us to preserve the saved
         * registers.
         */
        move    s0, a0                          # save argc
        move    s1, a1                          # save argv
        move    s2, a2                          # save envp
        move    s3, ra                          # save RA

        la      a0, _C_LABEL(edata)             # clear BSS
        move    a1, zero
        la      a2, _C_LABEL(end)
        jal     _C_LABEL(memset)                # memset(edata, 0, end - edata)
         subu   a2, a2, a0

        move    a0, s0                          # restore argc
        move    a1, s1                          # restore argv
        move    a2, s2                          # restore envp
        j       _C_LABEL(main)                  # main(argc, argv)
         move   ra, s3                          # restore RA

LEAF(romrestart)
XLEAF(_rtt)
        PTR_LA  v0, 0xBFC00000                  # indigo RESET
        j       v0
         nop
END(romrestart)