apps/plugin.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 Björn Stenberg
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19 #include "plugin.h"
  20 #include <ctype.h>
  21 #include <string.h>
  22 #include <sprintf.h>
  23 #include <atoi.h>
  24 #include "debug.h"
  25 #include "i2c.h"
  26 #include "lang.h"
  27 #include "keyboard.h"
  28 #include "buffer.h"
  29 #include "backlight.h"
  30 #include "sound_menu.h"
  31 #include "mp3data.h"
  32 #include "powermgmt.h"
  33 #include "splash.h"
  34 #include "logf.h"
  35 #include "option_select.h"
  36
  37 #if CONFIG_CHARGING
  38 #include "power.h"
  39 #endif
  40
  41 #ifdef HAVE_LCD_BITMAP
  42 #include "scrollbar.h"
  43 #include "peakmeter.h"
  44 #include "bmp.h"
  45 #include "bidi.h"
  46 #endif
  47
  48 #ifdef SIMULATOR
  49 static unsigned char pluginbuf[PLUGIN_BUFFER_SIZE];
  50 void *sim_plugin_load(char *plugin, void **pd);
  51 void sim_plugin_close(void *pd);
  52 void sim_lcd_ex_init(int shades, unsigned long (*getpixel)(int, int));
  53 void sim_lcd_ex_update_rect(int x, int y, int width, int height);
  54 #else
  55 #define sim_plugin_close(x)
  56 extern unsigned char pluginbuf[];
  57 #include "bitswap.h"
  58 #endif
  59
  60 /* for actual plugins only, not for codecs */
  61 static bool plugin_loaded = false;
  62 static int  plugin_size = 0;
  63 static bool (*pfn_tsr_exit)(bool reenter) = NULL; /* TSR exit callback */
  64 static char current_plugin[MAX_PATH];
  65
  66 extern struct thread_entry threads[MAXTHREADS];
  67
  68 static const struct plugin_api rockbox_api = {
  69
  70     /* lcd */
  71     lcd_set_contrast,
  72     lcd_update,
  73     lcd_clear_display,
  74     lcd_setmargins,
  75     lcd_getstringsize,
  76     lcd_putsxy,
  77     lcd_puts,
  78     lcd_puts_scroll,
  79     lcd_stop_scroll,
  80 #ifdef HAVE_LCD_CHARCELLS
  81     lcd_define_pattern,
  82     lcd_get_locked_pattern,
  83     lcd_unlock_pattern,
  84     lcd_putc,
  85     lcd_put_cursor,
  86     lcd_remove_cursor,
  87     lcd_icon,
  88     lcd_double_height,
  89 #else
  90     lcd_set_drawmode,
  91     lcd_get_drawmode,
  92     lcd_setfont,
  93     lcd_drawpixel,
  94     lcd_drawline,
  95     lcd_hline,
  96     lcd_vline,
  97     lcd_drawrect,
  98     lcd_fillrect,
  99     lcd_mono_bitmap_part,
 100     lcd_mono_bitmap,
 101 #if LCD_DEPTH > 1
 102     lcd_set_foreground,
 103     lcd_get_foreground,
 104     lcd_set_background,
 105     lcd_get_background,
 106     lcd_bitmap_part,
 107     lcd_bitmap,
 108     lcd_get_backdrop,
 109     lcd_set_backdrop,
 110 #endif
 111 #if LCD_DEPTH == 16
 112     lcd_bitmap_transparent_part,
 113     lcd_bitmap_transparent,
 114 #endif
 115     bidi_l2v,
 116     font_get_bits,
 117     font_load,
 118     lcd_puts_style,
 119     lcd_puts_scroll_style,
 120     &lcd_framebuffer[0][0],
 121     lcd_blit,
 122     lcd_update_rect,
 123     gui_scrollbar_draw,
 124     font_get,
 125     font_getstringsize,
 126     font_get_width,
 127 #endif
 128     backlight_on,
 129     backlight_off,
 130     backlight_set_timeout,
 131     gui_syncsplash,
 132 #ifdef HAVE_REMOTE_LCD
 133     /* remote lcd */
 134     lcd_remote_set_contrast,
 135     lcd_remote_clear_display,
 136     lcd_remote_puts,
 137     lcd_remote_puts_scroll,
 138     lcd_remote_stop_scroll,
 139     lcd_remote_set_drawmode,
 140     lcd_remote_get_drawmode,
 141     lcd_remote_setfont,
 142     lcd_remote_getstringsize,
 143     lcd_remote_drawpixel,
 144     lcd_remote_drawline,
 145     lcd_remote_hline,
 146     lcd_remote_vline,
 147     lcd_remote_drawrect,
 148     lcd_remote_fillrect,
 149     lcd_remote_mono_bitmap_part,
 150     lcd_remote_mono_bitmap,
 151     lcd_remote_putsxy,
 152     lcd_remote_puts_style,
 153     lcd_remote_puts_scroll_style,
 154     &lcd_remote_framebuffer[0][0],
 155     lcd_remote_update,
 156     lcd_remote_update_rect,
 157
 158     remote_backlight_on,
 159     remote_backlight_off,
 160 #endif
 161 #if NB_SCREENS == 2
 162     {&screens[SCREEN_MAIN], &screens[SCREEN_REMOTE]},
 163 #else
 164     {&screens[SCREEN_MAIN]},
 165 #endif
 166 #if defined(HAVE_REMOTE_LCD) && (LCD_REMOTE_DEPTH > 1)
 167     lcd_remote_set_foreground,
 168     lcd_remote_get_foreground,
 169     lcd_remote_set_background,
 170     lcd_remote_get_background,
 171     lcd_remote_bitmap_part,
 172     lcd_remote_bitmap,
 173 #endif
 174
 175 #if defined(HAVE_LCD_COLOR) && !defined(SIMULATOR)
 176     lcd_yuv_blit,
 177 #endif
 178     /* list */
 179     gui_synclist_init,
 180     gui_synclist_set_nb_items,
 181     gui_synclist_set_icon_callback,
 182     gui_synclist_get_nb_items,
 183     gui_synclist_get_sel_pos,
 184     gui_synclist_draw,
 185     gui_synclist_select_item,
 186     gui_synclist_add_item,
 187     gui_synclist_del_item,
 188     gui_synclist_limit_scroll,
 189     gui_synclist_flash,
 190     gui_synclist_do_button,
 191     gui_synclist_set_title,
 192
 193     /* button */
 194     button_get,
 195     button_get_w_tmo,
 196     button_status,
 197     button_clear_queue,
 198 #ifdef HAS_BUTTON_HOLD
 199     button_hold,
 200 #endif
 201
 202     /* file */
 203     (open_func)PREFIX(open),
 204     close,
 205     (read_func)read,
 206     PREFIX(lseek),
 207     (creat_func)PREFIX(creat),
 208     (write_func)write,
 209     PREFIX(remove),
 210     PREFIX(rename),
 211     PREFIX(ftruncate),
 212     PREFIX(filesize),
 213     fdprintf,
 214     read_line,
 215     settings_parseline,
 216 #ifndef SIMULATOR
 217     ata_sleep,
 218     ata_disk_is_active,
 219 #endif
 220     ata_spindown,
 221     reload_directory,
 222     create_numbered_filename,
 223
 224     /* dir */
 225     PREFIX(opendir),
 226     PREFIX(closedir),
 227     PREFIX(readdir),
 228     PREFIX(mkdir),
 229     PREFIX(rmdir),
 230
 231     /* dir, cached */
 232 #ifdef HAVE_DIRCACHE
 233     opendir_cached,
 234     readdir_cached,
 235     closedir_cached,
 236 #endif
 237
 238     /* kernel/ system */
 239     PREFIX(sleep),
 240     yield,
 241 #ifdef HAVE_PRIORITY_SCHEDULING
 242     priority_yield,
 243 #endif
 244     &current_tick,
 245     default_event_handler,
 246     default_event_handler_ex,
 247     threads,
 248     create_thread,
 249     remove_thread,
 250     reset_poweroff_timer,
 251 #ifndef SIMULATOR
 252     system_memory_guard,
 253     &cpu_frequency,
 254
 255 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
 256 #ifdef CPU_BOOST_LOGGING
 257     cpu_boost_,
 258 #else
 259     cpu_boost,
 260 #endif
 261 #endif
 262     timer_register,
 263     timer_unregister,
 264     timer_set_period,
 265 #endif
 266     queue_init,
 267     queue_delete,
 268     queue_post,
 269     queue_wait_w_tmo,
 270     usb_acknowledge,
 271 #ifdef RB_PROFILE
 272     profile_thread,
 273     profstop,
 274     profile_func_enter,
 275     profile_func_exit,
 276 #endif
 277
 278 #ifdef SIMULATOR
 279     /* special simulator hooks */
 280 #if defined(HAVE_LCD_BITMAP) && LCD_DEPTH < 8
 281     sim_lcd_ex_init,
 282     sim_lcd_ex_update_rect,
 283 #endif
 284 #endif
 285
 286     /* strings and memory */
 287     snprintf,
 288     vsnprintf,
 289     strcpy,
 290     strncpy,
 291     strlen,
 292     strrchr,
 293     strcmp,
 294     strncmp,
 295     strcasecmp,
 296     strncasecmp,
 297     memset,
 298     memcpy,
 299     memmove,
 300     _ctype_,
 301     atoi,
 302     strchr,
 303     strcat,
 304     memchr,
 305     memcmp,
 306     strcasestr,
 307     strtok_r,
 308     /* unicode stuff */
 309     utf8decode,
 310     iso_decode,
 311     utf16LEdecode,
 312     utf16BEdecode,
 313     utf8encode,
 314     utf8length,
 315     utf8seek,
 316
 317     /* sound */
 318 #if CONFIG_CODEC == SWCODEC
 319     sound_default,
 320 #endif
 321     sound_set,
 322
 323     sound_min,
 324     sound_max,
 325 #ifndef SIMULATOR
 326     mp3_play_data,
 327     mp3_play_pause,
 328     mp3_play_stop,
 329     mp3_is_playing,
 330 #if CONFIG_CODEC != SWCODEC
 331     bitswap,
 332 #endif
 333 #endif
 334 #if CONFIG_CODEC == SWCODEC
 335     &audio_master_sampr_list[0],
 336     &hw_freq_sampr[0],
 337     pcm_apply_settings,
 338     pcm_play_data,
 339     pcm_play_stop,
 340     pcm_set_frequency,
 341     pcm_is_playing,
 342     pcm_is_paused,
 343     pcm_play_pause,
 344     pcm_get_bytes_waiting,
 345     pcm_calculate_peaks,
 346 #ifdef HAVE_RECORDING
 347     &rec_freq_sampr[0],
 348     pcm_init_recording,
 349     pcm_close_recording,
 350     pcm_record_data,
 351     pcm_record_more,
 352     pcm_stop_recording,
 353     pcm_calculate_rec_peaks,
 354     audio_set_recording_gain,
 355 #endif /* HAVE_RECORDING */
 356 #if INPUT_SRC_CAPS != 0
 357     audio_set_output_source,
 358     audio_set_input_source,
 359 #endif
 360 #endif /* CONFIG_CODEC == SWCODEC */
 361
 362     /* playback control */
 363     playlist_amount,
 364     playlist_resume,
 365     playlist_start,
 366     PREFIX(audio_play),
 367     audio_stop,
 368     audio_pause,
 369     audio_resume,
 370     audio_next,
 371     audio_prev,
 372     audio_ff_rewind,
 373     audio_next_track,
 374     audio_status,
 375     audio_has_changed_track,
 376     audio_current_track,
 377     audio_flush_and_reload_tracks,
 378     audio_get_file_pos,
 379 #if !defined(SIMULATOR) && (CONFIG_CODEC != SWCODEC)
 380     mpeg_get_last_header,
 381 #endif
 382 #if (CONFIG_CODEC == MAS3587F) || (CONFIG_CODEC == MAS3539F) || \
 383     (CONFIG_CODEC == SWCODEC)
 384     sound_set_pitch,
 385 #endif
 386
 387 #if !defined(SIMULATOR) && (CONFIG_CODEC != SWCODEC)
 388     /* MAS communication */
 389     mas_readmem,
 390     mas_writemem,
 391     mas_readreg,
 392     mas_writereg,
 393 #if (CONFIG_CODEC == MAS3587F) || (CONFIG_CODEC == MAS3539F)
 394     mas_codec_writereg,
 395     mas_codec_readreg,
 396     i2c_begin,
 397     i2c_end,
 398     i2c_write,
 399 #endif
 400 #endif /* !SIMULATOR && CONFIG_CODEC != SWCODEC */
 401
 402     /* menu */
 403     do_menu,
 404     /* statusbars */
 405     &statusbars,
 406     gui_syncstatusbar_draw,
 407     /* options */
 408     find_setting,
 409     option_screen,
 410     set_option,
 411     set_bool_options,
 412     set_int,
 413     set_bool,
 414 #ifdef HAVE_LCD_COLOR
 415     set_color,
 416 #endif
 417
 418     /* action handling */
 419     get_custom_action,
 420     get_action,
 421     action_signalscreenchange,
 422     action_userabort,
 423
 424     /* power */
 425     battery_level,
 426     battery_level_safe,
 427     battery_time,
 428 #ifndef SIMULATOR
 429     battery_voltage,
 430 #endif
 431 #if CONFIG_CHARGING
 432     charger_inserted,
 433 # if CONFIG_CHARGING == CHARGING_MONITOR
 434     charging_state,
 435 # endif
 436 #endif
 437 #ifdef HAVE_USB_POWER
 438         usb_powered,
 439 #endif
 440
 441     /* misc */
 442     srand,
 443     rand,
 444     (qsort_func)qsort,
 445     kbd_input,
 446     get_time,
 447     set_time,
 448     plugin_get_buffer,
 449     plugin_get_audio_buffer,
 450     plugin_tsr,
 451 #ifdef IRAM_STEAL
 452     plugin_iram_init,
 453 #endif
 454 #if defined(DEBUG) || defined(SIMULATOR)
 455     debugf,
 456 #endif
 457 #ifdef ROCKBOX_HAS_LOGF
 458     _logf,
 459 #endif
 460     &global_settings,
 461     &global_status,
 462     mp3info,
 463     count_mp3_frames,
 464     create_xing_header,
 465     find_next_frame,
 466 #if (CONFIG_CODEC == MAS3587F) || (CONFIG_CODEC == MAS3539F)
 467     peak_meter_scale_value,
 468     peak_meter_set_use_dbfs,
 469     peak_meter_get_use_dbfs,
 470 #endif
 471 #ifdef HAVE_LCD_BITMAP
 472     read_bmp_file,
 473     screen_dump_set_hook,
 474 #endif
 475     show_logo,
 476     tree_get_context,
 477
 478 #ifdef HAVE_WHEEL_POSITION
 479     wheel_status,
 480     wheel_send_events,
 481 #endif
 482
 483 #ifdef IRIVER_H100_SERIES
 484     /* Routines for the iriver_flash -plugin. */
 485     detect_original_firmware,
 486     detect_flashed_ramimage,
 487     detect_flashed_romimage,
 488 #endif
 489     /* new stuff at the end, sort into place next time
 490        the API gets incompatible */
 491 #if NUM_CORES > 1
 492     spinlock_init,
 493     spinlock_lock,
 494     spinlock_unlock,
 495 #endif
 496
 497 #if (CONFIG_CODEC == SWCODEC)
 498     codec_load_file,
 499     get_codec_filename,
 500     get_metadata,
 501 #endif
 502 };
 503
 504 int plugin_load(const char* plugin, void* parameter)
 505 {
 506     int rc;
 507     struct plugin_header *hdr;
 508     const char *p = strrchr(plugin,'/');
 509 #ifdef SIMULATOR
 510     void *pd;
 511 #else
 512     int fd;
 513     ssize_t readsize;
 514 #endif
 515     int xm, ym;
 516 #ifdef HAVE_REMOTE_LCD
 517     int rxm, rym;
 518 #endif
 519
 520 #if LCD_DEPTH > 1
 521     fb_data* old_backdrop;
 522 #endif
 523
 524     if (!p)
 525         p = plugin;
 526     action_signalscreenchange();
 527
 528     if (pfn_tsr_exit != NULL) /* if we have a resident old plugin: */
 529     {
 530         if (pfn_tsr_exit(!strcmp(current_plugin,p)) == false )
 531         {
 532             /* not allowing another plugin to load */
 533             return PLUGIN_OK;
 534         }
 535         pfn_tsr_exit = NULL;
 536         plugin_loaded = false;
 537     }
 538
 539     gui_syncsplash(0, str(LANG_WAIT));
 540     strcpy(current_plugin,p);
 541
 542 #ifdef SIMULATOR
 543     hdr = sim_plugin_load((char *)plugin, &pd);
 544     if (pd == NULL) {
 545         gui_syncsplash(HZ*2, str(LANG_PLUGIN_CANT_OPEN), plugin);
 546         return -1;
 547     }
 548     if (hdr == NULL
 549         || hdr->magic != PLUGIN_MAGIC
 550         || hdr->target_id != TARGET_ID) {
 551         sim_plugin_close(pd);
 552         gui_syncsplash(HZ*2, str(LANG_PLUGIN_WRONG_MODEL));
 553         return -1;
 554     }
 555     if (hdr->api_version > PLUGIN_API_VERSION
 556         || hdr->api_version < PLUGIN_MIN_API_VERSION) {
 557         sim_plugin_close(pd);
 558         gui_syncsplash(HZ*2, str(LANG_PLUGIN_WRONG_VERSION));
 559         return -1;
 560     }
 561 #else
 562     fd = open(plugin, O_RDONLY);
 563     if (fd < 0) {
 564         gui_syncsplash(HZ*2, str(LANG_PLUGIN_CANT_OPEN), plugin);
 565         return fd;
 566     }
 567
 568     readsize = read(fd, pluginbuf, PLUGIN_BUFFER_SIZE);
 569     close(fd);
 570
 571     if (readsize < 0) {
 572         gui_syncsplash(HZ*2, str(LANG_READ_FAILED), plugin);
 573         return -1;
 574     }
 575     hdr = (struct plugin_header *)pluginbuf;
 576
 577     if ((unsigned)readsize <= sizeof(struct plugin_header)
 578         || hdr->magic != PLUGIN_MAGIC
 579         || hdr->target_id != TARGET_ID
 580         || hdr->load_addr != pluginbuf
 581         || hdr->end_addr > pluginbuf + PLUGIN_BUFFER_SIZE) {
 582         gui_syncsplash(HZ*2, str(LANG_PLUGIN_WRONG_MODEL));
 583         return -1;
 584     }
 585     if (hdr->api_version > PLUGIN_API_VERSION
 586         || hdr->api_version < PLUGIN_MIN_API_VERSION) {
 587         gui_syncsplash(HZ*2, str(LANG_PLUGIN_WRONG_VERSION));
 588         return -1;
 589     }
 590     plugin_size = hdr->end_addr - pluginbuf;
 591
 592     /* zero out bss area only, above guards end of pluginbuf */
 593     if (plugin_size > readsize)
 594         memset(pluginbuf + readsize, 0, plugin_size - readsize);
 595 #endif
 596
 597     plugin_loaded = true;
 598
 599     xm = lcd_getxmargin();
 600     ym = lcd_getymargin();
 601     lcd_setmargins(0,0);
 602
 603 #if defined HAVE_LCD_BITMAP && LCD_DEPTH > 1
 604     old_backdrop = lcd_get_backdrop();
 605 #endif
 606     lcd_clear_display();
 607     lcd_update();
 608
 609 #ifdef HAVE_REMOTE_LCD
 610     rxm = lcd_remote_getxmargin();
 611     rym = lcd_remote_getymargin();
 612     lcd_remote_setmargins(0, 0);
 613     lcd_remote_clear_display();
 614     lcd_remote_update();
 615 #endif
 616
 617     invalidate_icache();
 618
 619     rc = hdr->entry_point((struct plugin_api*) &rockbox_api, parameter);
 620     /* explicitly casting the pointer here to avoid touching every plugin. */
 621
 622     action_signalscreenchange();
 623     button_clear_queue();
 624
 625 #ifdef HAVE_LCD_BITMAP
 626 #if LCD_DEPTH > 1
 627     lcd_set_backdrop(old_backdrop);
 628 #ifdef HAVE_LCD_COLOR
 629     lcd_set_drawinfo(DRMODE_SOLID, global_settings.fg_color,
 630                                    global_settings.bg_color);
 631 #else
 632     lcd_set_drawinfo(DRMODE_SOLID, LCD_DEFAULT_FG, LCD_DEFAULT_BG);
 633 #endif
 634 #else /* LCD_DEPTH == 1 */
 635     lcd_set_drawmode(DRMODE_SOLID);
 636 #endif /* LCD_DEPTH */
 637 #endif /* HAVE_LCD_BITMAP */
 638
 639     /* restore margins */
 640     lcd_setmargins(xm,ym);
 641     lcd_clear_display();
 642     lcd_update();
 643
 644 #ifdef HAVE_REMOTE_LCD
 645 #if LCD_REMOTE_DEPTH > 1
 646     lcd_remote_set_drawinfo(DRMODE_SOLID, LCD_REMOTE_DEFAULT_FG,
 647                             LCD_REMOTE_DEFAULT_BG);
 648 #else
 649     lcd_remote_set_drawmode(DRMODE_SOLID);
 650 #endif
 651     lcd_remote_setmargins(rxm, rym);
 652     lcd_remote_clear_display();
 653     lcd_remote_update();
 654 #endif
 655
 656     if (pfn_tsr_exit == NULL)
 657         plugin_loaded = false;
 658
 659     sim_plugin_close(pd);
 660
 661     switch (rc) {
 662         case PLUGIN_OK:
 663             break;
 664
 665         case PLUGIN_USB_CONNECTED:
 666             return PLUGIN_USB_CONNECTED;
 667
 668         default:
 669             gui_syncsplash(HZ*2, str(LANG_PLUGIN_ERROR));
 670             break;
 671     }
 672     return PLUGIN_OK;
 673 }
 674
 675 /* Returns a pointer to the portion of the plugin buffer that is not already
 676    being used.  If no plugin is loaded, returns the entire plugin buffer */
 677 void* plugin_get_buffer(size_t *buffer_size)
 678 {
 679     int buffer_pos;
 680
 681     if (plugin_loaded)
 682     {
 683         if (plugin_size >= PLUGIN_BUFFER_SIZE)
 684             return NULL;
 685
 686         *buffer_size = PLUGIN_BUFFER_SIZE-plugin_size;
 687         buffer_pos = plugin_size;
 688     }
 689     else
 690     {
 691         *buffer_size = PLUGIN_BUFFER_SIZE;
 692         buffer_pos = 0;
 693     }
 694
 695     return &pluginbuf[buffer_pos];
 696 }
 697
 698 /* Returns a pointer to the mp3 buffer.
 699    Playback gets stopped, to avoid conflicts.
 700    Talk buffer is stolen as well.
 701  */
 702 void* plugin_get_audio_buffer(size_t *buffer_size)
 703 {
 704 #if CONFIG_CODEC == SWCODEC
 705     return audio_get_buffer(true, buffer_size);
 706 #else
 707     audio_stop();
 708     talk_buffer_steal(); /* we use the mp3 buffer, need to tell */
 709     *buffer_size = audiobufend - audiobuf;
 710     return audiobuf;
 711 #endif
 712 }
 713
 714 #ifdef IRAM_STEAL
 715 /* Initializes plugin IRAM */
 716 void plugin_iram_init(char *iramstart, char *iramcopy, size_t iram_size,
 717                       char *iedata, size_t iedata_size)
 718 {
 719     audio_iram_steal();
 720     memcpy(iramstart, iramcopy, iram_size);
 721     memset(iedata, 0, iedata_size);
 722     memset(iramcopy, 0, iram_size);
 723 }
 724 #endif /* IRAM_STEAL */
 725
 726 /* The plugin wants to stay resident after leaving its main function, e.g.
 727    runs from timer or own thread. The callback is registered to later
 728    instruct it to free its resources before a new plugin gets loaded. */
 729 void plugin_tsr(bool (*exit_callback)(bool))
 730 {
 731     pfn_tsr_exit = exit_callback; /* remember the callback for later */
 732 }