1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/bios.c	Mon Mar 13 12:37:06 2006 +0000
     1.3 @@ -0,0 +1,213 @@
     1.4 +/**
     1.5 + * $Id: bios.c,v 1.1 2006-01-22 22:40:53 nkeynes Exp $
     1.6 + * 
     1.7 + * "Fake" BIOS functions, for operation without the actual BIOS.
     1.8 + *
     1.9 + * Copyright (c) 2005 Nathan Keynes.
    1.10 + *
    1.11 + * This program is free software; you can redistribute it and/or modify
    1.12 + * it under the terms of the GNU General Public License as published by
    1.13 + * the Free Software Foundation; either version 2 of the License, or
    1.14 + * (at your option) any later version.
    1.15 + *
    1.16 + * This program is distributed in the hope that it will be useful,
    1.17 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    1.18 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    1.19 + * GNU General Public License for more details.
    1.20 + */
    1.21 +
    1.22 +#include "dream.h"
    1.23 +#include "mem.h"
    1.24 +#include "bios.h"
    1.25 +#include "sh4/sh4core.h"
    1.26 +
    1.27 +#define COMMAND_QUEUE_LENGTH 16
    1.28 +
    1.29 +/* TODO: Check if these are the real ATAPI command codes or not */
    1.30 +#define GD_CMD_PIOREAD     16
    1.31 +#define GD_CMD_DMAREAD     17
    1.32 +#define GD_CMD_GETTOC      18
    1.33 +#define GD_CMD_GETTOC2     19
    1.34 +#define GD_CMD_PLAY        20
    1.35 +#define GD_CMD_PLAY2       21
    1.36 +#define GD_CMD_PAUSE       22
    1.37 +#define GD_CMD_RELEASE     23
    1.38 +#define GD_CMD_INIT        24
    1.39 +#define GD_CMD_SEEK        27
    1.40 +#define GD_CMD_READ        28
    1.41 +#define GD_CMD_STOP        33
    1.42 +#define GD_CMD_GETSCD      34
    1.43 +#define GD_CMD_GETSES      35
    1.44 +
    1.45 +#define GD_CMD_STATUS_NONE 0
    1.46 +#define GD_CMD_STATUS_ACTIVE 1
    1.47 +#define GD_CMD_STATUS_DONE 2
    1.48 +#define GD_CMD_STATUS_ABORT 3
    1.49 +#define GD_CMD_STATUS_ERROR 4
    1.50 +
    1.51 +#define GD_ERROR_OK          0
    1.52 +#define GD_ERROR_NO_DISC     2
    1.53 +#define GD_ERROR_DISC_CHANGE 6
    1.54 +#define GD_ERROR_SYSTEM      1
    1.55 +
    1.56 +
    1.57 +typedef struct gdrom_command {
    1.58 +    int status;
    1.59 +    uint32_t cmd_code;
    1.60 +    char *data;
    1.61 +    uint32_t result[4];
    1.62 +} *gdrom_command_t;
    1.63 +
    1.64 +static struct gdrom_command gdrom_cmd_queue[COMMAND_QUEUE_LENGTH];
    1.65 +
    1.66 +static struct bios_gdrom_status {
    1.67 +    uint32_t status;
    1.68 +    uint32_t disk_type;
    1.69 +} bios_gdrom_status;
    1.70 +
    1.71 +void bios_gdrom_run_command( gdrom_command_t cmd )
    1.72 +{
    1.73 +    DEBUG( "BIOS GD command %d", cmd->cmd_code );
    1.74 +    switch( cmd->cmd_code ) {
    1.75 +    case GD_CMD_INIT:
    1.76 +	/* *shrug* */
    1.77 +	cmd->status = GD_CMD_STATUS_DONE;
    1.78 +	break;
    1.79 +    default:
    1.80 +	cmd->status = GD_CMD_STATUS_ERROR;
    1.81 +	cmd->result[0] = GD_ERROR_SYSTEM;
    1.82 +	break;
    1.83 +    }
    1.84 +}
    1.85 +
    1.86 +void bios_gdrom_init( void )
    1.87 +{
    1.88 +    memset( &gdrom_cmd_queue, 0, sizeof(gdrom_cmd_queue) );
    1.89 +}
    1.90 +
    1.91 +uint32_t bios_gdrom_enqueue( uint32_t cmd, char *ptr )
    1.92 +{
    1.93 +    int i;
    1.94 +    for( i=0; i<COMMAND_QUEUE_LENGTH; i++ ) {
    1.95 +	if( gdrom_cmd_queue[i].status != GD_CMD_STATUS_ACTIVE ) {
    1.96 +	    gdrom_cmd_queue[i].status = GD_CMD_STATUS_ACTIVE;
    1.97 +	    gdrom_cmd_queue[i].cmd_code = cmd;
    1.98 +	    gdrom_cmd_queue[i].data = ptr;
    1.99 +	    return i;
   1.100 +	}
   1.101 +    }
   1.102 +    return -1;
   1.103 +}
   1.104 +
   1.105 +void bios_gdrom_run_queue( void ) 
   1.106 +{
   1.107 +    int i;
   1.108 +    for( i=0; i<COMMAND_QUEUE_LENGTH; i++ ) {
   1.109 +	if( gdrom_cmd_queue[i].status == GD_CMD_STATUS_ACTIVE ) {
   1.110 +	    bios_gdrom_run_command( &gdrom_cmd_queue[i] );
   1.111 +	}
   1.112 +    }
   1.113 +}
   1.114 +
   1.115 +gdrom_command_t bios_gdrom_get_command( uint32_t id )
   1.116 +{
   1.117 +    if( id >= COMMAND_QUEUE_LENGTH ||
   1.118 +	gdrom_cmd_queue[id].status == GD_CMD_STATUS_NONE )
   1.119 +	return NULL;
   1.120 +    return &gdrom_cmd_queue[id];
   1.121 +}
   1.122 +
   1.123 +void bios_install( void ) 
   1.124 +{
   1.125 +    bios_gdrom_init();
   1.126 +    sh4_write_long( 0x8C0000B0, 0xFFFFFFB0 );
   1.127 +    sh4_write_long( 0x8C0000B4, 0xFFFFFFB4 );
   1.128 +    sh4_write_long( 0x8C0000B8, 0xFFFFFFB8 );
   1.129 +    sh4_write_long( 0x8C0000BC, 0xFFFFFFBC );
   1.130 +    sh4_write_long( 0x8C0000E0, 0xFFFFFFE0 );
   1.131 +}
   1.132 +
   1.133 +/**
   1.134 + * Syscall list courtesy of Marcus Comstedt
   1.135 + */
   1.136 +
   1.137 +void bios_syscall( uint32_t syscallid )
   1.138 +{
   1.139 +    gdrom_command_t cmd;
   1.140 +
   1.141 +    switch( syscallid ) {
   1.142 +    case 0xB0: /* sysinfo */
   1.143 +	break;
   1.144 +    case 0xB4: /* Font */
   1.145 +	break;
   1.146 +    case 0xB8: /* Flash */
   1.147 +	break;
   1.148 +    case 0xBC: /* Misc/GD-Rom */
   1.149 +	switch( sh4r.r[6] ) {
   1.150 +	case 0: /* GD-Rom */
   1.151 +	    switch( sh4r.r[7] ) {
   1.152 +	    case 0: /* Send command */
   1.153 +		if( sh4r.r[5] == 0 )
   1.154 +		    sh4r.r[0] = bios_gdrom_enqueue( sh4r.r[4], NULL );
   1.155 +		else
   1.156 +		    sh4r.r[0] = bios_gdrom_enqueue( sh4r.r[4], mem_get_region(sh4r.r[5]) );
   1.157 +		break;
   1.158 +	    case 1:  /* Check command */
   1.159 +		cmd = bios_gdrom_get_command( sh4r.r[4] );
   1.160 +		if( cmd == NULL ) {
   1.161 +		    sh4r.r[0] = GD_CMD_STATUS_NONE;
   1.162 +		} else {
   1.163 +		    sh4r.r[0] = cmd->status;
   1.164 +		    if( cmd->status == GD_CMD_STATUS_ERROR &&
   1.165 +			sh4r.r[5] != 0 ) {
   1.166 +			mem_copy_to_sh4( sh4r.r[5], &cmd->result, sizeof(cmd->result) );
   1.167 +		    }
   1.168 +		}
   1.169 +		break;
   1.170 +	    case 2: /* Mainloop */
   1.171 +		bios_gdrom_run_queue();
   1.172 +		break;
   1.173 +	    case 3: /* Init */
   1.174 +		bios_gdrom_init();
   1.175 +		break;
   1.176 +	    case 4: /* Drive status */
   1.177 +		if( sh4r.r[4] != 0 ) {
   1.178 +		    mem_copy_to_sh4( sh4r.r[4], &bios_gdrom_status, 
   1.179 +				      sizeof(bios_gdrom_status) );
   1.180 +		}
   1.181 +		sh4r.r[0] = 0;
   1.182 +		break;
   1.183 +	    case 8: /* Abort command */
   1.184 +		cmd = bios_gdrom_get_command( sh4r.r[4] );
   1.185 +		if( cmd == NULL || cmd->status != GD_CMD_STATUS_ACTIVE ) {
   1.186 +		    sh4r.r[0] = -1;
   1.187 +		} else {
   1.188 +		    cmd->status = GD_CMD_STATUS_ABORT;
   1.189 +		    sh4r.r[0] = 0;
   1.190 +		}
   1.191 +		break;
   1.192 +	    case 9: /* Reset */
   1.193 +		break;
   1.194 +	    case 10: /* Set mode */
   1.195 +		sh4r.r[0] = 0;
   1.196 +		break;
   1.197 +	    }
   1.198 +	    break;
   1.199 +	case -1: /* Misc */
   1.200 +	    break;
   1.201 +	default: /* ??? */
   1.202 +	    break;
   1.203 +	}
   1.204 +	break;
   1.205 +    case 0xE0: /* Menu */
   1.206 +	switch( sh4r.r[7] ) {
   1.207 +	case 0:
   1.208 +	    WARN( "Entering main program" );
   1.209 +	    break;
   1.210 +	case 1:
   1.211 +	    WARN( "Program aborted to DC menu");
   1.212 +	    dreamcast_stop();
   1.213 +	    break;
   1.214 +	}
   1.215 +    }
   1.216 +}