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     /* zero out the bss section */
  67 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
  68     rb->memset(plugin_bss_start, 0, plugin_end_addr - plugin_bss_start);
  69 #endif
  70     /* we come back here if exit() was called or the plugin returned normally */
  71     exit_ret = setjmp(__exit_env);
  72     if (exit_ret == 0)
  73     {   /* start the plugin */
  74         ret = plugin_start(param);
  75     }
  76     else
  77     {   /* plugin exit via exit() */
  78         if (exit_ret == EXIT_MAGIC)
  79         {   /* exit(EXIT_SUCCESS) */
  80             ret = PLUGIN_OK;
  81         }
  82         else if (exit_ret < INTERNAL_PLUGIN_RETVAL_START)
  83         {   /* exit(EXIT_FAILURE) */
  84             ret = PLUGIN_ERROR;
  85         }
  86         else
  87         {   /* exit(PLUGIN_XXX) */
  88             ret = (enum plugin_status)exit_ret;
  89         }
  90     }
  91
  92     /* before finishing, call the exit handler if there was one */
  93     if (atexit_handler != NULL)
  94         atexit_handler();
  95
  96     return ret;
  97 }
  98
  99 static void cleanup_wrapper(void *param)
 100 {
 101     (void)param;
 102     if (atexit_handler)
 103         atexit_handler();
 104 }
 105
 106 void exit_on_usb(int button)
 107 {   /* the default handler will call the exit handler before
 108      * showing the usb screen; after that we don't want the exit handler
 109      * to be called a second time, hence _exit()
 110      *
 111      * if not usb, then the handler will only be called if powering off
 112      * if poweroff, the plugin doesn't want to run any further so exit as well*/
 113     long result = rb->default_event_handler_ex(button, cleanup_wrapper, NULL);
 114     if (result == SYS_USB_CONNECTED)
 115         _exit(PLUGIN_USB_CONNECTED);
 116     else if (result == SYS_POWEROFF)
 117         _exit(PLUGIN_POWEROFF);
 118 }