/**

 * $Id: dcload.c,v 1.4 2006-07-06 08:47:33 nkeynes Exp $

 * 

 * DC-load syscall implementation.

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <stdio.h>

#include "dream.h"

#include "dreamcast.h"

#include "mem.h"

#include "syscall.h"

#include "sh4/sh4core.h"

#define SYS_READ 0

#define SYS_WRITE 1

#define SYS_OPEN 2

#define SYS_CLOSE 3

#define SYS_CREAT 4

#define SYS_LINK 5

#define SYS_UNLINK 6

#define SYS_CHDIR 7

#define SYS_CHMOD 8

#define SYS_LSEEK 9

#define SYS_FSTAT 10

#define SYS_TIME 11

#define SYS_STAT 12

#define SYS_UTIME 13

#define SYS_ASSIGNWRKMEM 14

#define SYS_EXIT 15

#define SYS_OPENDIR 16

#define SYS_CLOSEDIR 17

#define SYS_READDIR 18

#define SYS_GETHOSTINFO 19

#define SYS_MAGIC 0xDEADBEEF

#define SYS_MAGIC_ADDR 0x8c004004

#define SYSCALL_ADDR 0x8c004008

static gboolean dcload_allow_exit = FALSE;

void dcload_set_allow_exit( gboolean allow )

{

    dcload_allow_exit = allow;

}

void dcload_syscall( uint32_t syscall_id ) 

{

    uint32_t syscall = sh4r.r[4];

    switch( sh4r.r[4] ) {

    case SYS_READ:

	if( sh4r.r[5] == 0 ) {

	    char *buf = mem_get_region( sh4r.r[6] );

	    int length = sh4r.r[7];

	    sh4r.r[0] = read( 0, buf, length );

	} else {

	    sh4r.r[0] = -1;

	}

	break;

    case SYS_WRITE:

	if( sh4r.r[5] == 1 || sh4r.r[5] == 2 ) {

	    char *buf = mem_get_region( sh4r.r[6] );

	    int length = sh4r.r[7];

	    sh4r.r[0] = write( sh4r.r[5], buf, length );

	} else {

	    sh4r.r[0] = -1;

	}

	break;

    case SYS_EXIT:

	if( dcload_allow_exit ) 

	    exit( sh4r.r[4] );

	else

	    dreamcast_stop();

    default:

	sh4r.r[0] = -1;

    }

}

void dcload_install() 

{

    syscall_add_hook_vector( 0xF0, SYSCALL_ADDR, dcload_syscall );

    sh4_write_long( SYS_MAGIC_ADDR, SYS_MAGIC );

}