filename | src/dreamcast.c |
changeset | 480:d28c2992f5ee |
prev | 477:9a373f2ff009 |
next | 543:361ec0a70cf2 |
author | nkeynes |
date | Wed Nov 14 10:21:33 2007 +0000 (16 years ago) |
permissions | -rw-r--r-- |
last change | Use an explicit 32-bit type for region flags (save-file compatibility) Ensure page map is fully cleared |
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1 /**
2 * $Id: dreamcast.c,v 1.28 2007-10-31 11:53:35 nkeynes Exp $
3 * Central switchboard for the system. This pulls all the individual modules
4 * together into some kind of coherent structure. This is also where you'd
5 * add Naomi support, if I ever get a board to play with...
6 *
7 * Copyright (c) 2005 Nathan Keynes.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 */
20 #include <errno.h>
21 #include "dream.h"
22 #include "config.h"
23 #include "mem.h"
24 #include "aica/aica.h"
25 #include "asic.h"
26 #include "dreamcast.h"
27 #include "gdrom/ide.h"
28 #include "maple/maple.h"
30 /**
31 * Current state of the DC virtual machine
32 */
33 #define STATE_UNINIT 0
34 #define STATE_RUNNING 1
35 #define STATE_STOPPING 2
36 #define STATE_STOPPED 3
37 static volatile int dreamcast_state = STATE_UNINIT;
38 static uint32_t timeslice_length = DEFAULT_TIMESLICE_LENGTH;
39 const char *dreamcast_config = "DEFAULT";
41 #define MAX_MODULES 32
42 static int num_modules = 0;
43 dreamcast_module_t modules[MAX_MODULES];
45 /**
46 * The unknown module is used for logging files without an actual module
47 * declaration
48 */
49 struct dreamcast_module unknown_module = { "****", NULL, NULL, NULL, NULL,
50 NULL, NULL, NULL };
52 /**
53 * This function is responsible for defining how all the pieces of the
54 * dreamcast actually fit together.
55 *
56 * Note currently the locations of the various MMIO pages are hard coded in
57 * the MMIO definitions - they should probably be moved here.
58 */
59 void dreamcast_configure( )
60 {
61 dreamcast_register_module( &eventq_module );
62 /* Register the memory framework */
63 dreamcast_register_module( &mem_module );
65 /* Setup standard memory map */
66 mem_create_repeating_ram_region( 0x0C000000, 16 MB, MEM_REGION_MAIN, 0x01000000, 0x0F000000 );
67 mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );
68 mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );
69 mem_create_ram_region( 0x05000000, 8 MB, MEM_REGION_VIDEO );
70 mem_load_rom( lxdream_get_config_value(CONFIG_BIOS_PATH),
71 0x00000000, 0x00200000, 0x89f2b1a1, MEM_REGION_BIOS );
72 mem_create_ram_region( 0x00200000, 0x00020000, MEM_REGION_FLASH );
73 mem_load_block( lxdream_get_config_value(CONFIG_FLASH_PATH),
74 0x00200000, 0x00020000 );
76 /* Load in the rest of the core modules */
77 dreamcast_register_module( &sh4_module );
78 dreamcast_register_module( &asic_module );
79 dreamcast_register_module( &pvr2_module );
80 dreamcast_register_module( &aica_module );
81 dreamcast_register_module( &maple_module );
82 dreamcast_register_module( &ide_module );
83 }
85 void dreamcast_config_changed(void)
86 {
87 mem_load_rom( lxdream_get_config_value(CONFIG_BIOS_PATH),
88 0x00000000, 0x00200000, 0x89f2b1a1, MEM_REGION_BIOS );
89 mem_load_block( lxdream_get_config_value(CONFIG_FLASH_PATH),
90 0x00200000, 0x00020000 );
91 }
93 void dreamcast_save_flash()
94 {
95 const char *file = lxdream_get_config_value(CONFIG_FLASH_PATH);
96 mem_save_block( file, 0x00200000, 0x00020000 );
97 }
99 /**
100 * Constructs a system configuration for the AICA in standalone mode,
101 * ie sound chip only.
102 */
103 void dreamcast_configure_aica_only( )
104 {
105 dreamcast_register_module( &mem_module );
106 mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );
107 mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );
108 dreamcast_register_module( &aica_module );
109 aica_enable();
110 dreamcast_state = STATE_STOPPED;
111 }
113 void dreamcast_register_module( dreamcast_module_t module )
114 {
115 modules[num_modules++] = module;
116 if( module->init != NULL )
117 module->init();
118 }
121 void dreamcast_init( void )
122 {
123 dreamcast_configure();
124 dreamcast_state = STATE_STOPPED;
125 }
127 void dreamcast_reset( void )
128 {
129 int i;
130 for( i=0; i<num_modules; i++ ) {
131 if( modules[i]->reset != NULL )
132 modules[i]->reset();
133 }
134 }
136 void dreamcast_run( void )
137 {
138 int i;
139 if( dreamcast_state != STATE_RUNNING ) {
140 for( i=0; i<num_modules; i++ ) {
141 if( modules[i]->start != NULL )
142 modules[i]->start();
143 }
144 }
145 dreamcast_state = STATE_RUNNING;
146 while( dreamcast_state == STATE_RUNNING ) {
147 int time_to_run = timeslice_length;
148 for( i=0; i<num_modules; i++ ) {
149 if( modules[i]->run_time_slice != NULL )
150 time_to_run = modules[i]->run_time_slice( time_to_run );
151 }
153 }
155 for( i=0; i<num_modules; i++ ) {
156 if( modules[i]->stop != NULL )
157 modules[i]->stop();
158 }
159 dreamcast_state = STATE_STOPPED;
160 }
162 void dreamcast_run_for( unsigned int seconds, unsigned int nanosecs )
163 {
165 int i;
166 if( dreamcast_state != STATE_RUNNING ) {
167 for( i=0; i<num_modules; i++ ) {
168 if( modules[i]->start != NULL )
169 modules[i]->start();
170 }
171 }
172 dreamcast_state = STATE_RUNNING;
173 uint32_t nanos = 0;
174 if( nanosecs != 0 ) {
175 nanos = 1000000000 - nanosecs;
176 seconds++;
177 }
178 while( dreamcast_state == STATE_RUNNING && seconds != 0 ) {
179 int time_to_run = timeslice_length;
180 for( i=0; i<num_modules; i++ ) {
181 if( modules[i]->run_time_slice != NULL )
182 time_to_run = modules[i]->run_time_slice( time_to_run );
183 }
184 nanos += time_to_run;
185 if( nanos >= 1000000000 ) {
186 nanos -= 1000000000;
187 seconds--;
188 }
189 }
191 for( i=0; i<num_modules; i++ ) {
192 if( modules[i]->stop != NULL )
193 modules[i]->stop();
194 }
195 dreamcast_state = STATE_STOPPED;
196 }
198 void dreamcast_stop( void )
199 {
200 if( dreamcast_state == STATE_RUNNING )
201 dreamcast_state = STATE_STOPPING;
202 }
204 void dreamcast_shutdown()
205 {
206 dreamcast_stop();
207 dreamcast_save_flash();
208 }
210 gboolean dreamcast_is_running( void )
211 {
212 return dreamcast_state == STATE_RUNNING;
213 }
215 /********************************* Save States *****************************/
217 struct save_state_header {
218 char magic[16];
219 uint32_t version;
220 uint32_t module_count;
221 };
223 struct chunk_header {
224 char marker[4]; /* Always BLCK */
225 char name[8]; /* Block (module) name */
226 uint32_t block_length;
227 };
229 /**
230 * Check the save state header to ensure that it is a valid, supported
231 * file.
232 * @return the number of blocks following, or 0 if the file is invalid.
233 */
234 int dreamcast_read_save_state_header( FILE *f )
235 {
236 struct save_state_header header;
237 if( fread( &header, sizeof(header), 1, f ) != 1 ) {
238 return 0;
239 }
240 if( strncmp( header.magic, DREAMCAST_SAVE_MAGIC, 16 ) != 0 ) {
241 ERROR( "Not a %s save state file", APP_NAME );
242 return 0;
243 }
244 if( header.version != DREAMCAST_SAVE_VERSION ) {
245 ERROR( "%s save state version not supported", APP_NAME );
246 return 0;
247 }
248 if( header.module_count > MAX_MODULES ) {
249 ERROR( "%s save state is corrupted (bad module count)", APP_NAME );
250 return 0;
251 }
252 return header.module_count;
253 }
255 int dreamcast_write_chunk_header( const gchar *name, uint32_t length, FILE *f )
256 {
257 struct chunk_header head;
259 memcpy( head.marker, "BLCK", 4 );
260 memset( head.name, 0, 8 );
261 memcpy( head.name, name, strlen(name) );
262 head.block_length = length;
263 return fwrite( &head, sizeof(head), 1, f );
264 }
267 frame_buffer_t dreamcast_load_preview( const gchar *filename )
268 {
269 int i;
270 FILE *f = fopen( filename, "r" );
271 if( f == NULL ) return NULL;
273 int module_count = dreamcast_read_save_state_header(f);
274 if( module_count <= 0 ) {
275 fclose(f);
276 return NULL;
277 }
278 for( i=0; i<module_count; i++ ) {
279 struct chunk_header head;
280 if( fread( &head, sizeof(head), 1, f ) != 1 ) {
281 fclose(f);
282 return NULL;
283 }
284 if( memcmp("BLCK", head.marker, 4) != 0 ) {
285 fclose(f);
286 return NULL;
287 }
289 if( strcmp("PVR2", head.name) == 0 ) {
290 uint32_t buf_count;
291 int has_front;
292 fread( &buf_count, sizeof(buf_count), 1, f );
293 fread( &has_front, sizeof(has_front), 1, f );
294 if( buf_count != 0 && has_front ) {
295 frame_buffer_t result = read_png_from_stream(f);
296 fclose(f);
297 return result;
298 }
299 break;
300 } else {
301 fseek( f, head.block_length, SEEK_CUR );
302 }
303 }
304 return NULL;
305 }
307 int dreamcast_load_state( const gchar *filename )
308 {
309 int i,j;
310 int module_count;
311 int have_read[MAX_MODULES];
313 FILE *f = fopen( filename, "r" );
314 if( f == NULL ) return errno;
316 module_count = dreamcast_read_save_state_header(f);
317 if( module_count <= 0 ) {
318 fclose(f);
319 return 1;
320 }
322 for( i=0; i<MAX_MODULES; i++ ) {
323 have_read[i] = 0;
324 }
326 for( i=0; i<module_count; i++ ) {
327 struct chunk_header chunk;
328 fread( &chunk, sizeof(chunk), 1, f );
329 if( strncmp(chunk.marker, "BLCK", 4) != 0 ) {
330 ERROR( "%s save state is corrupted (missing block header %d)", APP_NAME, i );
331 fclose(f);
332 return 2;
333 }
335 /* Find the matching module by name */
336 for( j=0; j<num_modules; j++ ) {
337 if( strcmp(modules[j]->name,chunk.name) == 0 ) {
338 have_read[j] = 1;
339 if( modules[j]->load == NULL ) {
340 ERROR( "%s save state is corrupted (no loader for %s)", APP_NAME, modules[j]->name );
341 fclose(f);
342 return 2;
343 } else if( modules[j]->load(f) != 0 ) {
344 ERROR( "%s save state is corrupted (%s failed)", APP_NAME, modules[j]->name );
345 fclose(f);
346 return 2;
347 }
348 break;
349 }
350 }
351 if( j == num_modules ) {
352 fclose(f);
353 ERROR( "%s save state contains unrecognized section", APP_NAME );
354 return 2;
355 }
356 }
358 /* Any modules that we didn't load - reset to the default state.
359 * (ie it's not an error to skip a module if you don't actually
360 * care about its state).
361 */
362 for( j=0; j<num_modules; j++ ) {
363 if( have_read[j] == 0 && modules[j]->reset != NULL ) {
364 modules[j]->reset();
365 }
366 }
367 fclose(f);
368 INFO( "Save state read from %s", filename );
369 return 0;
370 }
372 int dreamcast_save_state( const gchar *filename )
373 {
374 int i;
375 FILE *f;
376 struct save_state_header header;
378 f = fopen( filename, "w" );
379 if( f == NULL )
380 return errno;
381 strcpy( header.magic, DREAMCAST_SAVE_MAGIC );
382 header.version = DREAMCAST_SAVE_VERSION;
383 header.module_count = 0;
385 for( i=0; i<num_modules; i++ ) {
386 if( modules[i]->save != NULL )
387 header.module_count++;
388 }
389 fwrite( &header, sizeof(header), 1, f );
390 for( i=0; i<num_modules; i++ ) {
391 if( modules[i]->save != NULL ) {
392 uint32_t blocklen, posn1, posn2;
393 dreamcast_write_chunk_header( modules[i]->name, 0, f );
394 posn1 = ftell(f);
395 modules[i]->save(f);
396 posn2 = ftell(f);
397 blocklen = posn2 - posn1;
398 fseek( f, posn1-4, SEEK_SET );
399 fwrite( &blocklen, sizeof(blocklen), 1, f );
400 fseek( f, posn2, SEEK_SET );
401 }
402 }
403 fclose( f );
404 INFO( "Save state written to %s", filename );
405 return 0;
406 }
.