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         /* make the icache (if it exists) up to date with the new code */
  80         rb->commit_discard_idcache();
  81
  82         /* barrier to prevent reordering iram copy and BSS clearing,
  83          * because the BSS segment alias the IRAM copy.
  84          */
  85         asm volatile ("" ::: "memory");
  86     }
  87 #endif /* PLUGIN_USE_IRAM */
  88
  89     /* zero out the bss section */
  90     rb->memset(plugin_bss_start, 0, plugin_end_addr - plugin_bss_start);
  91
  92     /* Some parts of bss may be used via a no-cache alias (at least
  93      * portalplayer has this). If we don't clear the cache, those aliases
  94      * may read garbage */
  95     rb->commit_dcache();
  96 #endif
  97
  98     /* we come back here if exit() was called or the plugin returned normally */
  99     exit_ret = setjmp(__exit_env);
 100     if (exit_ret == 0)
 101     {   /* start the plugin */
 102         ret = plugin_start(param);
 103     }
 104     else
 105     {   /* plugin exit via exit() */
 106         if (exit_ret == EXIT_MAGIC)
 107         {   /* exit(EXIT_SUCCESS) */
 108             ret = PLUGIN_OK;
 109         }
 110         else if (exit_ret < INTERNAL_PLUGIN_RETVAL_START)
 111         {   /* exit(EXIT_FAILURE) */
 112             ret = PLUGIN_ERROR;
 113         }
 114         else
 115         {   /* exit(PLUGIN_XXX) */
 116             ret = (enum plugin_status)exit_ret;
 117         }
 118     }
 119
 120     /* before finishing, call the exit handler if there was one */
 121     if (atexit_handler != NULL)
 122         atexit_handler();
 123
 124     return ret;
 125 }
 126
 127 static void cleanup_wrapper(void *param)
 128 {
 129     (void)param;
 130     if (atexit_handler)
 131         atexit_handler();
 132 }
 133
 134 void exit_on_usb(int button)
 135 {   /* the default handler will call the exit handler before
 136      * showing the usb screen; after that we don't want the exit handler
 137      * to be called a second time, hence _exit()
 138      *
 139      * if not usb, then the handler will only be called if powering off
 140      * if poweroff, the plugin doesn't want to run any further so exit as well*/
 141     long result = rb->default_event_handler_ex(button, cleanup_wrapper, NULL);
 142     if (result == SYS_USB_CONNECTED)
 143         _exit(PLUGIN_USB_CONNECTED);
 144     else if (result == SYS_POWEROFF)
 145         _exit(PLUGIN_POWEROFF);
 146 }