apps/plugins/plugin_crt0.c

   1 /***************************************************************************
   2 *             __________               __   ___.
   3 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7 *                     \/            \/     \/    \/            \/
   8 * $Id$
   9 *
  10 * Copyright (C) 2010 by Thomas Martitz
  11 *
  12 * This program is free software; you can redistribute it and/or
  13 * modify it under the terms of the GNU General Public License
  14 * as published by the Free Software Foundation; either version 2
  15 * of the License, or (at your option) any later version.
  16 *
  17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18 * KIND, either express or implied.
  19 *
  20 ****************************************************************************/
  21
  22
  23 #include "plugin.h"
  24 #include <setjmp.h>
  25
  26 PLUGIN_HEADER
  27
  28 /*
  29  * EXIT_MAGIC magic, because 0 cannot be used due to setjmp()
  30  * must be > 0
  31  */
  32 #define EXIT_MAGIC 0x0CDEBABE
  33
  34 extern enum plugin_status plugin_start(const void*);
  35 extern unsigned char plugin_bss_start[];
  36 extern unsigned char plugin_end_addr[];
  37
  38 static jmp_buf __exit_env;
  39 /* only 1 atexit handler for now, chain in the exit handler if you need more */
  40 static void (*atexit_handler)(void);
  41
  42 int rb_atexit(void (*fn)(void))
  43 {
  44     if (atexit_handler)
  45         return -1;
  46     atexit_handler = fn;
  47     return 0;
  48 }
  49
  50 void exit(int status)
  51 {   /* jump back in time to before starting the plugin */
  52     longjmp(__exit_env, status != 0 ? status : EXIT_MAGIC);
  53 }
  54
  55 void _exit(int status)
  56 {   /* don't call exit handler */
  57     atexit_handler = NULL;
  58     exit(status);
  59 }
  60
  61 enum plugin_status plugin__start(const void *param)
  62 {
  63     int exit_ret;
  64     enum plugin_status ret;
  65
  66 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
  67
  68 /* IRAM must be copied before clearing the BSS ! */
  69 #ifdef PLUGIN_USE_IRAM
  70     extern char iramcopy[], iramstart[], iramend[], iedata[], iend[];
  71     size_t iram_size = iramend - iramstart;
  72     size_t ibss_size = iend - iedata;
  73     if (iram_size > 0 || ibss_size > 0)
  74     {
  75         /* We need to stop audio playback in order to use codec IRAM */
  76         rb->audio_stop();
  77         rb->memcpy(iramstart, iramcopy, iram_size);
  78         rb->memset(iedata, 0, ibss_size);
  79 #ifdef HAVE_CPUCACHE_INVALIDATE
  80         /* make the icache (if it exists) up to date with the new code */
  81         rb->cpucache_invalidate();
  82 #endif /* HAVE_CPUCACHE_INVALIDATE */
  83
  84         /* barrier to prevent reordering iram copy and BSS clearing,
  85          * because the BSS segment alias the IRAM copy.
  86          */
  87         asm volatile ("" ::: "memory");
  88     }
  89 #endif /* PLUGIN_USE_IRAM */
  90
  91     /* zero out the bss section */
  92     rb->memset(plugin_bss_start, 0, plugin_end_addr - plugin_bss_start);
  93
  94 #ifdef HAVE_CPUCACHE_INVALIDATE
  95     /* Some parts of bss may be used via a no-cache alias (at least
  96      * portalplayer has this). If we don't clear the cache, those aliases
  97      * may read garbage */
  98     rb->cpucache_invalidate();
  99 #endif /* HAVE_CPUCACHE_INVALIDATE */
 100 #endif
 101
 102     /* we come back here if exit() was called or the plugin returned normally */
 103     exit_ret = setjmp(__exit_env);
 104     if (exit_ret == 0)
 105     {   /* start the plugin */
 106         ret = plugin_start(param);
 107     }
 108     else
 109     {   /* plugin exit via exit() */
 110         if (exit_ret == EXIT_MAGIC)
 111         {   /* exit(EXIT_SUCCESS) */
 112             ret = PLUGIN_OK;
 113         }
 114         else if (exit_ret < INTERNAL_PLUGIN_RETVAL_START)
 115         {   /* exit(EXIT_FAILURE) */
 116             ret = PLUGIN_ERROR;
 117         }
 118         else
 119         {   /* exit(PLUGIN_XXX) */
 120             ret = (enum plugin_status)exit_ret;
 121         }
 122     }
 123
 124     /* before finishing, call the exit handler if there was one */
 125     if (atexit_handler != NULL)
 126         atexit_handler();
 127
 128     return ret;
 129 }
 130
 131 static void cleanup_wrapper(void *param)
 132 {
 133     (void)param;
 134     if (atexit_handler)
 135         atexit_handler();
 136 }
 137
 138 void exit_on_usb(int button)
 139 {   /* the default handler will call the exit handler before
 140      * showing the usb screen; after that we don't want the exit handler
 141      * to be called a second time, hence _exit()
 142      *
 143      * if not usb, then the handler will only be called if powering off
 144      * if poweroff, the plugin doesn't want to run any further so exit as well*/
 145     long result = rb->default_event_handler_ex(button, cleanup_wrapper, NULL);
 146     if (result == SYS_USB_CONNECTED)
 147         _exit(PLUGIN_USB_CONNECTED);
 148     else if (result == SYS_POWEROFF)
 149         _exit(PLUGIN_POWEROFF);
 150 }