apps/codecs/codec_crt0.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 Tomasz Malesinski
  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 #include "config.h"
  23 #include "codecs.h"
  24
  25 struct codec_api *ci DATA_ATTR;
  26
  27 extern unsigned char plugin_bss_start[];
  28 extern unsigned char plugin_end_addr[];
  29
  30 extern enum codec_status codec_main(enum codec_entry_call_reason reason);
  31
  32 /* stub, the entry point is called via its reference in __header to
  33  * avoid warning with certain compilers */
  34 int _start(void) {return 0;}
  35
  36 enum codec_status codec_start(enum codec_entry_call_reason reason)
  37 {
  38 #if (CONFIG_PLATFORM & PLATFORM_NATIVE)
  39     if (reason == CODEC_LOAD)
  40     {
  41 #ifdef USE_IRAM
  42         extern char iramcopy[], iramstart[], iramend[], iedata[], iend[];
  43         size_t iram_size = iramend - iramstart;
  44         size_t ibss_size = iend - iedata;
  45         if (iram_size > 0 || ibss_size > 0)
  46         {
  47             ci->memcpy(iramstart, iramcopy, iram_size);
  48             ci->memset(iedata, 0, ibss_size);
  49             /* make the icache (if it exists) up to date with the new code */
  50             ci->cpucache_invalidate();
  51             /* barrier to prevent reordering iram copy and BSS clearing,
  52              * because the BSS segment alias the IRAM copy.
  53              */
  54             asm volatile ("" ::: "memory");
  55         }
  56 #endif /* PLUGIN_USE_IRAM */
  57         ci->memset(plugin_bss_start, 0, plugin_end_addr - plugin_bss_start);
  58         /* Some parts of bss may be used via a no-cache alias (at least
  59          * portalplayer has this). If we don't clear the cache, those aliases
  60          * may read garbage */
  61         ci->cpucache_invalidate();
  62     }
  63 #endif /* CONFIG_PLATFORM */
  64
  65     /* Note: If for any reason codec_main would not be called with CODEC_LOAD
  66      * because the above code failed then it must not be ever be called with
  67      * any other value and some strategy to avoid doing so must be conceived */
  68     return codec_main(reason);
  69 }
  70
  71 #if defined(CPU_ARM) && (CONFIG_PLATFORM & PLATFORM_NATIVE)
  72 void __attribute__((naked)) __div0(void)
  73 {
  74     asm volatile("bx %0" : : "r"(ci->__div0));
  75 }
  76 #endif