rockbox/apps/plugin.c

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 Björn Stenberg
 *
 * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "plugin.h"
#include <ctype.h>
#include <string.h>
#include <sprintf.h>
#include <stdlib.h>
#include "debug.h"
#include "i2c.h"
#include "lang.h"
#include "led.h"
#include "keyboard.h"
#include "buffer.h"
#include "backlight.h"
#include "sound_menu.h"
#include "mp3data.h"
#include "powermgmt.h"
#include "splash.h"
#include "logf.h"
#include "option_select.h"
#include "talk.h"
#include "version.h"
#include "storage.h"

#if CONFIG_CHARGING
#include "power.h"
#endif

#ifdef HAVE_LCD_BITMAP
#include "scrollbar.h"
#include "peakmeter.h"
#include "bmp.h"
#include "bidi.h"
#endif

#if defined(HAVE_USBSTACK) && defined(USB_ENABLE_HID)
#include "usbstack/usb_hid.h"
#endif

#ifdef SIMULATOR
#define PREFIX(_x_) sim_ ## _x_
#else
#define PREFIX
#endif

#ifdef SIMULATOR
static unsigned char pluginbuf[PLUGIN_BUFFER_SIZE];
void *sim_plugin_load(char *plugin, void **pd);
void sim_plugin_close(void *pd);
void sim_lcd_ex_init(unsigned long (*getpixel)(int, int));
void sim_lcd_ex_update_rect(int x, int y, int width, int height);
#else
#define sim_plugin_close(x)
extern unsigned char pluginbuf[];
#include "bitswap.h"
#endif

/* for actual plugins only, not for codecs */
static bool plugin_loaded = false;
static int  plugin_size = 0;
static bool (*pfn_tsr_exit)(bool reenter) = NULL; /* TSR exit callback */
static char current_plugin[MAX_PATH];

char *plugin_get_current_filename(void);

static const struct plugin_api rockbox_api = {

    /* lcd */
#ifdef HAVE_LCD_CONTRAST
    lcd_set_contrast,
#endif
    lcd_update,
    lcd_clear_display,
    lcd_getstringsize,
    lcd_putsxy,
    lcd_puts,
    lcd_puts_scroll,
    lcd_stop_scroll,
#ifdef HAVE_LCD_CHARCELLS
    lcd_define_pattern,
    lcd_get_locked_pattern,
    lcd_unlock_pattern,
    lcd_putc,
    lcd_put_cursor,
    lcd_remove_cursor,
    lcd_icon,
    lcd_double_height,
#else
    &lcd_framebuffer[0][0],
    lcd_update_rect,
    lcd_set_drawmode,
    lcd_get_drawmode,
    lcd_setfont,
    lcd_drawpixel,
    lcd_drawline,
    lcd_hline,
    lcd_vline,
    lcd_drawrect,
    lcd_fillrect,
    lcd_mono_bitmap_part,
    lcd_mono_bitmap,
#if LCD_DEPTH > 1
    lcd_set_foreground,
    lcd_get_foreground,
    lcd_set_background,
    lcd_get_background,
    lcd_bitmap_part,
    lcd_bitmap,
    lcd_get_backdrop,
    lcd_set_backdrop,
#endif
#if LCD_DEPTH == 16
    lcd_bitmap_transparent_part,
    lcd_bitmap_transparent,
#if MEMORYSIZE > 2
    lcd_blit_yuv,
#if defined(TOSHIBA_GIGABEAT_F) || defined(SANSA_E200) || defined(SANSA_C200) \
    || defined(IRIVER_H10) || defined(COWON_D2) || defined(PHILIPS_HDD1630) \
    || defined(SANSA_FUZE) || defined(SANSA_E200V2) || defined(TOSHIBA_GIGABEAT_S)
    lcd_yuv_set_options,
#endif
#endif /* MEMORYSIZE > 2 */
#elif (LCD_DEPTH < 4) && !defined(SIMULATOR)
    lcd_blit_mono,
    lcd_blit_grey_phase,
#endif /* LCD_DEPTH */
#if defined(HAVE_LCD_MODES) && (HAVE_LCD_MODES & LCD_MODE_PAL256)
    lcd_blit_pal256,
    lcd_pal256_update_pal,
#endif
    lcd_puts_style,
    lcd_puts_scroll_style,
#ifdef HAVE_LCD_INVERT
    lcd_set_invert_display,
#endif /* HAVE_LCD_INVERT */
#if defined(HAVE_LCD_MODES)
    lcd_set_mode,
#endif
#if defined(HAVE_LCD_ENABLE) || defined(HAVE_LCD_SLEEP)
    lcd_activation_set_hook,
    &button_queue,
#endif
    bidi_l2v,
    font_get_bits,
    font_load,
    font_get,
    font_getstringsize,
    font_get_width,
    screen_clear_area,
    gui_scrollbar_draw,
#endif /* HAVE_LCD_BITMAP */
    get_codepage_name,

    backlight_on,
    backlight_off,
    backlight_set_timeout,
#ifdef HAVE_BACKLIGHT_BRIGHTNESS
    backlight_set_brightness,
#endif /* HAVE_BACKLIGHT_BRIGHTNESS */

#if CONFIG_CHARGING
    backlight_set_timeout_plugged,
#endif
    is_backlight_on,
    splash,
    splashf,

#ifdef HAVE_REMOTE_LCD
    /* remote lcd */
    lcd_remote_set_contrast,
    lcd_remote_clear_display,
    lcd_remote_puts,
    lcd_remote_puts_scroll,
    lcd_remote_stop_scroll,
    lcd_remote_set_drawmode,
    lcd_remote_get_drawmode,
    lcd_remote_setfont,
    lcd_remote_getstringsize,
    lcd_remote_drawpixel,
    lcd_remote_drawline,
    lcd_remote_hline,
    lcd_remote_vline,
    lcd_remote_drawrect,
    lcd_remote_fillrect,
    lcd_remote_mono_bitmap_part,
    lcd_remote_mono_bitmap,
    lcd_remote_putsxy,
    lcd_remote_puts_style,
    lcd_remote_puts_scroll_style,
    &lcd_remote_framebuffer[0][0],
    lcd_remote_update,
    lcd_remote_update_rect,

    remote_backlight_on,
    remote_backlight_off,
    remote_backlight_set_timeout,
#if CONFIG_CHARGING
    remote_backlight_set_timeout_plugged,
#endif
#endif /* HAVE_REMOTE_LCD */
#if NB_SCREENS == 2
    {&screens[SCREEN_MAIN], &screens[SCREEN_REMOTE]},
#else
    {&screens[SCREEN_MAIN]},
#endif
#if defined(HAVE_REMOTE_LCD) && (LCD_REMOTE_DEPTH > 1)
    lcd_remote_set_foreground,
    lcd_remote_get_foreground,
    lcd_remote_set_background,
    lcd_remote_get_background,
    lcd_remote_bitmap_part,
    lcd_remote_bitmap,
#endif
    viewport_set_defaults,
    viewportmanager_set_statusbar,
    
    /* list */
    gui_synclist_init,
    gui_synclist_set_nb_items,
    gui_synclist_set_icon_callback,
    gui_synclist_get_nb_items,
    gui_synclist_get_sel_pos,
    gui_synclist_draw,
    gui_synclist_select_item,
    gui_synclist_add_item,
    gui_synclist_del_item,
    gui_synclist_limit_scroll,
    gui_synclist_do_button,
    gui_synclist_set_title,
    gui_syncyesno_run,
    simplelist_info_init,
    simplelist_show_list,

    /* button */
    button_get,
    button_get_w_tmo,
    button_status,
#ifdef HAVE_BUTTON_DATA
    button_get_data,
#endif
    button_clear_queue,
    button_queue_count,
#ifdef HAS_BUTTON_HOLD
    button_hold,
#endif
#ifdef HAVE_TOUCHSCREEN
    touchscreen_set_mode,
#endif
    
#ifdef HAVE_BUTTON_LIGHT
    buttonlight_set_timeout,
    buttonlight_off,
    buttonlight_on,
#ifdef HAVE_BUTTONLIGHT_BRIGHTNESS
    buttonlight_set_brightness,
#endif /* HAVE_BUTTONLIGHT_BRIGHTNESS */
#endif /* HAVE_BUTTON_LIGHT */

    /* file */
    (open_func)PREFIX(open),
    PREFIX(close),
    (read_func)PREFIX(read),
    PREFIX(lseek),
    (creat_func)PREFIX(creat),
    (write_func)PREFIX(write),
    PREFIX(remove),
    PREFIX(rename),
    PREFIX(ftruncate),
    PREFIX(filesize),
    fdprintf,
    read_line,
    settings_parseline,
    storage_sleep,
    storage_spin,
    storage_spindown,
#if USING_STORAGE_CALLBACK
    register_storage_idle_func,
    unregister_storage_idle_func,
#endif /* USING_STORAGE_CALLBACK */
    reload_directory,
    create_numbered_filename,
    file_exists,
    strip_extension,

    /* dir */
    opendir,
    closedir,
    readdir,
    mkdir,
    rmdir,
    dir_exists,

    /* kernel/ system */
#ifdef CPU_ARM
    __div0,
#endif
    PREFIX(sleep),
    yield,
    &current_tick,
    default_event_handler,
    default_event_handler_ex,
    create_thread,
    thread_exit,
    thread_wait,
#if (CONFIG_CODEC == SWCODEC)
    thread_thaw,
#ifdef HAVE_PRIORITY_SCHEDULING
    thread_set_priority,
#endif
    mutex_init,
    mutex_lock,
    mutex_unlock,
#endif

    reset_poweroff_timer,
#ifndef SIMULATOR
    system_memory_guard,
    &cpu_frequency,

#ifdef HAVE_ADJUSTABLE_CPU_FREQ
#ifdef CPU_BOOST_LOGGING
    cpu_boost_,
#else
    cpu_boost,
#endif
#endif /* HAVE_ADJUSTABLE_CPU_FREQ */
#endif /* !SIMULATOR */
#ifdef HAVE_SCHEDULER_BOOSTCTRL
    trigger_cpu_boost,
    cancel_cpu_boost,
#endif
#if NUM_CORES > 1
    cpucache_flush,
    cpucache_invalidate,
#endif
    timer_register,
    timer_unregister,
    timer_set_period,

    queue_init,
    queue_delete,
    queue_post,
    queue_wait_w_tmo,
#if CONFIG_CODEC == SWCODEC
    queue_enable_queue_send,
    queue_empty,
    queue_wait,
    queue_send,
    queue_reply,
#endif
    usb_acknowledge,
#if defined(HAVE_USBSTACK) && defined(USB_ENABLE_HID)
    usb_hid_send,
#endif
#ifdef RB_PROFILE
    profile_thread,
    profstop,
    __cyg_profile_func_enter,
    __cyg_profile_func_exit,
#endif

#ifdef SIMULATOR
    /* special simulator hooks */
#if defined(HAVE_LCD_BITMAP) && LCD_DEPTH < 8
    sim_lcd_ex_init,
    sim_lcd_ex_update_rect,
#endif
#endif

    /* strings and memory */
    snprintf,
    vsnprintf,
    strcpy,
    strlcpy,
    strlen,
    strrchr,
    strcmp,
    strncmp,
    strcasecmp,
    strncasecmp,
    memset,
    memcpy,
    memmove,
    _ctype_,
    atoi,
    strchr,
    strcat,
    memchr,
    memcmp,
    strcasestr,
    strtok_r,
    /* unicode stuff */
    utf8decode,
    iso_decode,
    utf16LEdecode,
    utf16BEdecode,
    utf8encode,
    utf8length,
    utf8seek,

    /* sound */
    sound_set,
    sound_default,
    sound_min,
    sound_max,
    sound_unit,
    sound_val2phys,
#ifndef SIMULATOR
    mp3_play_data,
    mp3_play_pause,
    mp3_play_stop,
    mp3_is_playing,
#if CONFIG_CODEC != SWCODEC
    bitswap,
#endif
#endif
#if CONFIG_CODEC == SWCODEC
    &audio_master_sampr_list[0],
    &hw_freq_sampr[0],
    pcm_apply_settings,
    pcm_play_data,
    pcm_play_stop,
    pcm_set_frequency,
    pcm_is_playing,
    pcm_is_paused,
    pcm_play_pause,
    pcm_get_bytes_waiting,
    pcm_calculate_peaks,
    pcm_play_lock,
    pcm_play_unlock,
#ifdef HAVE_RECORDING
    &rec_freq_sampr[0],
    pcm_init_recording,
    pcm_close_recording,
    pcm_record_data,
    pcm_record_more,
    pcm_stop_recording,
    pcm_calculate_rec_peaks,
    audio_set_recording_gain,
#endif /* HAVE_RECORDING */
#if INPUT_SRC_CAPS != 0
    audio_set_output_source,
    audio_set_input_source,
#endif
    dsp_set_crossfeed,
    dsp_set_eq,
    dsp_dither_enable,
    dsp_configure,
    dsp_process,
    dsp_input_count,
    dsp_output_count,
    dsp_flush_limiter_buffer,
#endif /* CONFIG_CODEC == SWCODEC */

    /* playback control */
    playlist_amount,
    playlist_resume,
    playlist_start,
    playlist_add,
    playlist_sync,
    playlist_remove_all_tracks,
    playlist_create,
    playlist_insert_track,
    playlist_insert_directory,
    playlist_shuffle,
    PREFIX(audio_play),
    audio_stop,
    audio_pause,
    audio_resume,
    audio_next,
    audio_prev,
    audio_ff_rewind,
    audio_next_track,
    audio_status,
    audio_current_track,
    audio_flush_and_reload_tracks,
    audio_get_file_pos,
#if !defined(SIMULATOR) && (CONFIG_CODEC != SWCODEC)
    mpeg_get_last_header,
#endif
#if (CONFIG_CODEC == MAS3587F) || (CONFIG_CODEC == MAS3539F) || \
    (CONFIG_CODEC == SWCODEC)
    sound_set_pitch,
#endif

#if !defined(SIMULATOR) && (CONFIG_CODEC != SWCODEC)
    /* MAS communication */
    mas_readmem,
    mas_writemem,
    mas_readreg,
    mas_writereg,
#if (CONFIG_CODEC == MAS3587F) || (CONFIG_CODEC == MAS3539F)
    mas_codec_writereg,
    mas_codec_readreg,
    i2c_begin,
    i2c_end,
    i2c_write,
#endif
#endif /* !SIMULATOR && CONFIG_CODEC != SWCODEC */

    /* menu */
    do_menu,
    /* statusbars */
    &statusbars,
    gui_syncstatusbar_draw,
    /* options */
    get_settings_list,
    find_setting,
    option_screen,
    set_option,
    set_bool_options,
    set_int,
    set_bool,
#ifdef HAVE_LCD_COLOR
    set_color,
#endif

    /* action handling */
    get_custom_action,
    get_action,
#ifdef HAVE_TOUCHSCREEN
    action_get_touchscreen_press,
#endif
    action_userabort,

    /* power */
    battery_level,
    battery_level_safe,
    battery_time,
#ifndef SIMULATOR
    battery_voltage,
#endif
#if CONFIG_CHARGING
    charger_inserted,
# if CONFIG_CHARGING >= CHARGING_MONITOR
    charging_state,
# endif
#endif
#ifdef HAVE_USB_POWER
    usb_powered,
#endif

    /* misc */
    srand,
    rand,
    (qsort_func)qsort,
    kbd_input,
    get_time,
    set_time,
#if CONFIG_RTC
    mktime,
#endif
    plugin_get_buffer,
    plugin_get_audio_buffer,
    plugin_tsr,
    plugin_get_current_filename,
#ifdef PLUGIN_USE_IRAM
    plugin_iram_init,
#endif
#if defined(DEBUG) || defined(SIMULATOR)
    debugf,
#endif
#ifdef ROCKBOX_HAS_LOGF
    _logf,
#endif
    &global_settings,
    &global_status,
    talk_disable,
#if CONFIG_CODEC == SWCODEC
    codec_thread_do_callback,
    codec_load_file,
    get_codec_filename,
#endif
    get_metadata,
    mp3info,
    count_mp3_frames,
    create_xing_header,
    find_next_frame,
#if (CONFIG_CODEC == MAS3587F) || (CONFIG_CODEC == MAS3539F)
    peak_meter_scale_value,
    peak_meter_set_use_dbfs,
    peak_meter_get_use_dbfs,
#endif
#ifdef HAVE_LCD_BITMAP
    read_bmp_file,
    read_bmp_fd,
#ifdef HAVE_JPEG
    read_jpeg_file,
    read_jpeg_fd,
#endif
    screen_dump_set_hook,
#endif
    show_logo,
    tree_get_context,
    set_current_file,
    set_dirfilter,

#ifdef HAVE_WHEEL_POSITION
    wheel_status,
    wheel_send_events,
#endif

#ifdef IRIVER_H100_SERIES
    /* Routines for the iriver_flash -plugin. */
    detect_original_firmware,
    detect_flashed_ramimage,
    detect_flashed_romimage,
#endif
    led,
#if (CONFIG_CODEC == SWCODEC)
    bufopen,
    bufalloc,
    bufclose,
    bufseek,
    bufadvance,
    bufread,
    bufgetdata,
    bufgettail,
    bufcuttail,

    buf_get_offset,
    buf_handle_offset,
    buf_request_buffer_handle,
    buf_set_base_handle,
    buf_used,
#endif

#ifdef HAVE_TAGCACHE
    tagcache_search,
    tagcache_search_set_uniqbuf,
    tagcache_search_add_filter,
    tagcache_get_next,
    tagcache_retrieve,
    tagcache_search_finish,
    tagcache_get_numeric,
#ifdef HAVE_TC_RAMCACHE
    tagcache_fill_tags,
#endif
#endif

#ifdef HAVE_ALBUMART
    search_albumart_files,
#endif

#ifdef HAVE_SEMAPHORE_OBJECTS
    semaphore_init,
    semaphore_wait,
    semaphore_release,
#endif

    appsversion,
    /* new stuff at the end, sort into place next time
       the API gets incompatible */
};

int plugin_load(const char* plugin, const void* parameter)
{
    int rc, i;
    int oldbars;
    struct plugin_header *hdr;
    struct viewport plugin_vp[NB_SCREENS];
#ifdef SIMULATOR
    void *pd;
#else /* !SIMULATOR */
    int fd;
    ssize_t readsize;
#if NUM_CORES > 1
    unsigned my_core;
#endif
#endif /* !SIMULATOR */

#if LCD_DEPTH > 1
    fb_data* old_backdrop;
#endif

    if (pfn_tsr_exit != NULL) /* if we have a resident old plugin: */
    {
        if (pfn_tsr_exit(!strcmp(current_plugin, plugin)) == false )
        {
            /* not allowing another plugin to load */
            return PLUGIN_OK;
        }
        pfn_tsr_exit = NULL;
        plugin_loaded = false;
    }

    splash(0, ID2P(LANG_WAIT));
    strcpy(current_plugin, plugin);

#ifdef SIMULATOR
    hdr = sim_plugin_load((char *)plugin, &pd);
    if (pd == NULL) {
        splashf(HZ*2, str(LANG_PLUGIN_CANT_OPEN), plugin);
        return -1;
    }
    if (hdr == NULL
        || hdr->magic != PLUGIN_MAGIC
        || hdr->target_id != TARGET_ID) {
        sim_plugin_close(pd);
        splash(HZ*2, str(LANG_PLUGIN_WRONG_MODEL));
        return -1;
    }
    if (hdr->api_version > PLUGIN_API_VERSION
        || hdr->api_version < PLUGIN_MIN_API_VERSION) {
        sim_plugin_close(pd);
        splash(HZ*2, str(LANG_PLUGIN_WRONG_VERSION));
        return -1;
    }
#else
    fd = open(plugin, O_RDONLY);
    if (fd < 0) {
        splashf(HZ*2, str(LANG_PLUGIN_CANT_OPEN), plugin);
        return fd;
    }
#if NUM_CORES > 1
    /* Make sure COP cache is flushed and invalidated before loading */
    my_core = switch_core(CURRENT_CORE ^ 1);
    cpucache_invalidate();
    switch_core(my_core);
#endif

    readsize = read(fd, pluginbuf, PLUGIN_BUFFER_SIZE);
    close(fd);

    if (readsize < 0) {
        splashf(HZ*2, str(LANG_READ_FAILED), plugin);
        return -1;
    }
    hdr = (struct plugin_header *)pluginbuf;

    if ((unsigned)readsize <= sizeof(struct plugin_header)
        || hdr->magic != PLUGIN_MAGIC
        || hdr->target_id != TARGET_ID
        || hdr->load_addr != pluginbuf
        || hdr->end_addr > pluginbuf + PLUGIN_BUFFER_SIZE) {
        splash(HZ*2, str(LANG_PLUGIN_WRONG_MODEL));
        return -1;
    }
    if (hdr->api_version > PLUGIN_API_VERSION
        || hdr->api_version < PLUGIN_MIN_API_VERSION) {
        splash(HZ*2, str(LANG_PLUGIN_WRONG_VERSION));
        return -1;
    }
    plugin_size = hdr->end_addr - pluginbuf;

    /* zero out bss area only, above guards end of pluginbuf */
    if (plugin_size > readsize)
        memset(pluginbuf + readsize, 0, plugin_size - readsize);
#endif

    *(hdr->api) = &rockbox_api;
    plugin_loaded = true;
    

#if defined HAVE_LCD_BITMAP && LCD_DEPTH > 1
    old_backdrop = lcd_get_backdrop();
#endif
    lcd_clear_display();
    lcd_update();

#ifdef HAVE_REMOTE_LCD
    lcd_remote_clear_display();
    lcd_remote_update();
#endif

    oldbars = viewportmanager_set_statusbar(VP_SB_HIDE_ALL);

    FOR_NB_SCREENS(i)
        viewport_set_fullscreen(&plugin_vp[i], i);

    viewport_set_current_vp(plugin_vp);

    cpucache_invalidate();
    
#ifdef HAVE_TOUCHSCREEN
    touchscreen_set_mode(TOUCHSCREEN_BUTTON);
#endif

    rc = hdr->entry_point(parameter);
    
    /* Go back to the global setting in case the plugin changed it */
#ifdef HAVE_TOUCHSCREEN
    touchscreen_set_mode(global_settings.touch_mode);
#endif
    
    viewportmanager_set_statusbar(oldbars);

    button_clear_queue();

#ifdef HAVE_LCD_BITMAP
    lcd_setfont(FONT_UI);
#if LCD_DEPTH > 1
    lcd_set_backdrop(old_backdrop);
#ifdef HAVE_LCD_COLOR
    lcd_set_drawinfo(DRMODE_SOLID, global_settings.fg_color,
                                   global_settings.bg_color);
#else
    lcd_set_drawinfo(DRMODE_SOLID, LCD_DEFAULT_FG, LCD_DEFAULT_BG);
#endif
#else /* LCD_DEPTH == 1 */
    lcd_set_drawmode(DRMODE_SOLID);
#endif /* LCD_DEPTH */
#endif /* HAVE_LCD_BITMAP */


#ifdef HAVE_REMOTE_LCD
#if LCD_REMOTE_DEPTH > 1
    lcd_remote_set_drawinfo(DRMODE_SOLID, LCD_REMOTE_DEFAULT_FG,
                            LCD_REMOTE_DEFAULT_BG);
#else
    lcd_remote_set_drawmode(DRMODE_SOLID);
#endif
#endif

    if (rc != PLUGIN_GOTO_WPS)
    {
        send_event(GUI_EVENT_REFRESH, NULL);
    }

    viewportmanager_set_statusbar(oldbars);
    viewport_set_current_vp(NULL);
    if (pfn_tsr_exit == NULL)
        plugin_loaded = false;

    sim_plugin_close(pd);

    if (rc == PLUGIN_ERROR)
        splash(HZ*2, str(LANG_PLUGIN_ERROR));

    return rc;
}

/* Returns a pointer to the portion of the plugin buffer that is not already
   being used.  If no plugin is loaded, returns the entire plugin buffer */
void* plugin_get_buffer(size_t *buffer_size)
{
    int buffer_pos;

    if (plugin_loaded)
    {
        if (plugin_size >= PLUGIN_BUFFER_SIZE)
            return NULL;

        *buffer_size = PLUGIN_BUFFER_SIZE-plugin_size;
        buffer_pos = plugin_size;
    }
    else
    {
        *buffer_size = PLUGIN_BUFFER_SIZE;
        buffer_pos = 0;
    }

    return &pluginbuf[buffer_pos];
}

/* Returns a pointer to the mp3 buffer.
   Playback gets stopped, to avoid conflicts.
   Talk buffer is stolen as well.
 */
void* plugin_get_audio_buffer(size_t *buffer_size)
{
#if CONFIG_CODEC == SWCODEC
    return audio_get_buffer(true, buffer_size);
#else
    audio_stop();
    talk_buffer_steal(); /* we use the mp3 buffer, need to tell */
    *buffer_size = audiobufend - audiobuf;
    return audiobuf;
#endif
}

#ifdef PLUGIN_USE_IRAM
/* Initializes plugin IRAM */
void plugin_iram_init(char *iramstart, char *iramcopy, size_t iram_size,
                      char *iedata, size_t iedata_size)
{
    /* We need to stop audio playback in order to use codec IRAM */
    audio_hard_stop();
    memcpy(iramstart, iramcopy, iram_size);
    memset(iedata, 0, iedata_size);
    memset(iramcopy, 0, iram_size);
#if NUM_CORES > 1
    /* writeback cleared iedata and iramcopy areas */
    cpucache_flush();
#endif
}
#endif /* PLUGIN_USE_IRAM */

/* The plugin wants to stay resident after leaving its main function, e.g.
   runs from timer or own thread. The callback is registered to later
   instruct it to free its resources before a new plugin gets loaded. */
void plugin_tsr(bool (*exit_callback)(bool))
{
    pfn_tsr_exit = exit_callback; /* remember the callback for later */
}

char *plugin_get_current_filename(void)
{
    return current_plugin;
}