/**

  * $Id: dcload.c,v 1.5 2006-07-06 22:44:39 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[5] );

 	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 );

 }