/**

 * $Id: syscall.c,v 1.1 2006-03-13 12:38:34 nkeynes Exp $

 * 

 * Routines to add hook functions that are callable from the SH4

 *

 * 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 "dream.h"

#include "mem.h"

#include "syscall.h"

#include "sh4/sh4core.h"

struct syscall_hook {

    syscall_hook_func_t hook;

    sh4addr_t vector;

} syscall_hooks[256];

void syscall_add_hook( uint32_t hook_id, syscall_hook_func_t hook ) 

{

    hook_id &= 0xFF;

    if( syscall_hooks[hook_id].hook != NULL )

	WARN( "Overwriting existing hook %02X", hook_id );

    syscall_hooks[hook_id].hook = hook;

    syscall_hooks[hook_id].vector = 0;

}

void syscall_add_hook_vector( uint32_t hook_id, uint32_t vector_addr,

			      syscall_hook_func_t hook )

{

    hook_id &= 0xFF;

    syscall_add_hook( hook_id, hook );

    syscall_hooks[hook_id].vector = vector_addr;

    sh4_write_long( vector_addr, 0xFFFFFF00 + hook_id );

}

void syscall_invoke( uint32_t hook_id )

{

    hook_id &= 0xFF;

    syscall_hook_func_t hook = syscall_hooks[hook_id].hook;

    if( hook == NULL ) {

	WARN( "Invoked non-existent hook %02X", hook_id );

    } else {

	hook(hook_id);

    }

}

void syscall_repatch_vectors( )

{

    int i;

    for( i=0; i<256; i++ ) {

	if( syscall_hooks[i].hook != NULL &&

	    syscall_hooks[i].vector != 0 ) {

	    sh4_write_long( syscall_hooks[i].vector, 0xFFFFFF00 + i );

	}

    }

}