2 * $Id: bios.c,v 1.2 2006-03-13 12:38:34 nkeynes Exp $
4 * "Fake" BIOS functions, for operation without the actual BIOS.
6 * Copyright (c) 2005 Nathan Keynes.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
22 #include "sh4/sh4core.h"
24 #define COMMAND_QUEUE_LENGTH 16
26 /* TODO: Check if these are the real ATAPI command codes or not */
27 #define GD_CMD_PIOREAD 16
28 #define GD_CMD_DMAREAD 17
29 #define GD_CMD_GETTOC 18
30 #define GD_CMD_GETTOC2 19
31 #define GD_CMD_PLAY 20
32 #define GD_CMD_PLAY2 21
33 #define GD_CMD_PAUSE 22
34 #define GD_CMD_RELEASE 23
35 #define GD_CMD_INIT 24
36 #define GD_CMD_SEEK 27
37 #define GD_CMD_READ 28
38 #define GD_CMD_STOP 33
39 #define GD_CMD_GETSCD 34
40 #define GD_CMD_GETSES 35
42 #define GD_CMD_STATUS_NONE 0
43 #define GD_CMD_STATUS_ACTIVE 1
44 #define GD_CMD_STATUS_DONE 2
45 #define GD_CMD_STATUS_ABORT 3
46 #define GD_CMD_STATUS_ERROR 4
49 #define GD_ERROR_NO_DISC 2
50 #define GD_ERROR_DISC_CHANGE 6
51 #define GD_ERROR_SYSTEM 1
54 typedef struct gdrom_command {
61 static struct gdrom_command gdrom_cmd_queue[COMMAND_QUEUE_LENGTH];
63 static struct bios_gdrom_status {
68 void bios_gdrom_run_command( gdrom_command_t cmd )
70 DEBUG( "BIOS GD command %d", cmd->cmd_code );
71 switch( cmd->cmd_code ) {
74 cmd->status = GD_CMD_STATUS_DONE;
77 cmd->status = GD_CMD_STATUS_ERROR;
78 cmd->result[0] = GD_ERROR_SYSTEM;
83 void bios_gdrom_init( void )
85 memset( &gdrom_cmd_queue, 0, sizeof(gdrom_cmd_queue) );
88 uint32_t bios_gdrom_enqueue( uint32_t cmd, char *ptr )
91 for( i=0; i<COMMAND_QUEUE_LENGTH; i++ ) {
92 if( gdrom_cmd_queue[i].status != GD_CMD_STATUS_ACTIVE ) {
93 gdrom_cmd_queue[i].status = GD_CMD_STATUS_ACTIVE;
94 gdrom_cmd_queue[i].cmd_code = cmd;
95 gdrom_cmd_queue[i].data = ptr;
102 void bios_gdrom_run_queue( void )
105 for( i=0; i<COMMAND_QUEUE_LENGTH; i++ ) {
106 if( gdrom_cmd_queue[i].status == GD_CMD_STATUS_ACTIVE ) {
107 bios_gdrom_run_command( &gdrom_cmd_queue[i] );
112 gdrom_command_t bios_gdrom_get_command( uint32_t id )
114 if( id >= COMMAND_QUEUE_LENGTH ||
115 gdrom_cmd_queue[id].status == GD_CMD_STATUS_NONE )
117 return &gdrom_cmd_queue[id];
121 * Syscall list courtesy of Marcus Comstedt
124 void bios_syscall( uint32_t syscallid )
128 switch( syscallid ) {
129 case 0xB0: /* sysinfo */
131 case 0xB4: /* Font */
133 case 0xB8: /* Flash */
135 case 0xBC: /* Misc/GD-Rom */
136 switch( sh4r.r[6] ) {
138 switch( sh4r.r[7] ) {
139 case 0: /* Send command */
141 sh4r.r[0] = bios_gdrom_enqueue( sh4r.r[4], NULL );
143 sh4r.r[0] = bios_gdrom_enqueue( sh4r.r[4], mem_get_region(sh4r.r[5]) );
145 case 1: /* Check command */
146 cmd = bios_gdrom_get_command( sh4r.r[4] );
148 sh4r.r[0] = GD_CMD_STATUS_NONE;
150 sh4r.r[0] = cmd->status;
151 if( cmd->status == GD_CMD_STATUS_ERROR &&
153 mem_copy_to_sh4( sh4r.r[5], &cmd->result, sizeof(cmd->result) );
157 case 2: /* Mainloop */
158 bios_gdrom_run_queue();
163 case 4: /* Drive status */
164 if( sh4r.r[4] != 0 ) {
165 mem_copy_to_sh4( sh4r.r[4], &bios_gdrom_status,
166 sizeof(bios_gdrom_status) );
170 case 8: /* Abort command */
171 cmd = bios_gdrom_get_command( sh4r.r[4] );
172 if( cmd == NULL || cmd->status != GD_CMD_STATUS_ACTIVE ) {
175 cmd->status = GD_CMD_STATUS_ABORT;
181 case 10: /* Set mode */
192 case 0xE0: /* Menu */
193 switch( sh4r.r[7] ) {
195 WARN( "Entering main program" );
198 WARN( "Program aborted to DC menu");
205 void bios_install( void )
208 syscall_add_hook_vector( 0xB0, 0x8C0000B0, bios_syscall );
209 syscall_add_hook_vector( 0xB4, 0x8C0000B4, bios_syscall );
210 syscall_add_hook_vector( 0xB8, 0x8C0000B8, bios_syscall );
211 syscall_add_hook_vector( 0xBC, 0x8C0000BC, bios_syscall );
212 syscall_add_hook_vector( 0xE0, 0x8C0000E0, bios_syscall );
.