firmware/load_code.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 #include "config.h"
  23 #include "system.h"
  24 #include "file.h"
  25 #include "debug.h"
  26 #include "load_code.h"
  27
  28 /* load binary blob from disk to memory, returning a handle */
  29 void * lc_open(const char *filename, unsigned char *buf, size_t buf_size)
  30 {
  31     int fd = open(filename, O_RDONLY);
  32     ssize_t read_size;
  33     struct lc_header hdr;
  34     unsigned char *buf_end = buf+buf_size;
  35     off_t copy_size;
  36
  37     if (fd < 0)
  38     {
  39         DEBUGF("Could not open file");
  40         goto error;
  41     }
  42
  43 #if NUM_CORES > 1
  44     /* Make sure COP cache is flushed and invalidated before loading */
  45     {
  46         int my_core = switch_core(CURRENT_CORE ^ 1);
  47         switch_core(my_core);
  48     }
  49 #endif
  50
  51     /* read the header to obtain the load address */
  52     read_size = read(fd, &hdr, sizeof(hdr));
  53
  54     if (read_size < 0)
  55     {
  56         DEBUGF("Could not read from file");
  57         goto error_fd;
  58     }
  59
  60     /* hdr.end_addr points to the end of the bss section,
  61      * but there might be idata/icode behind that so the bytes to copy
  62      * can be larger */
  63     copy_size = MAX(filesize(fd), hdr.end_addr - hdr.load_addr);
  64
  65     if (hdr.load_addr < buf || (hdr.load_addr+copy_size) > buf_end)
  66     {
  67         DEBUGF("Binary doesn't fit into memory");
  68         goto error_fd;
  69     }
  70
  71     /* go back to beginning to load the whole thing (incl. header) */
  72     if (lseek(fd, 0, SEEK_SET) < 0)
  73     {
  74         DEBUGF("lseek failed");
  75         goto error_fd;
  76     }
  77
  78     /* the header has the addresses where the code is linked at */
  79     read_size = read(fd, hdr.load_addr, copy_size);
  80     close(fd);
  81
  82     if (read_size < 0)
  83     {
  84         DEBUGF("Could not read from file");
  85         goto error;
  86     }
  87
  88     /* commit dcache and discard icache */
  89     commit_discard_idcache();
  90     /* return a pointer the header, reused by lc_get_header() */
  91     return hdr.load_addr;
  92
  93 error_fd:
  94     close(fd);
  95 error:
  96     return NULL;
  97 }