src/image/segment.c

   1 /*
   2  * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 /**
  20  * @file
  21  *
  22  * Executable image segments
  23  *
  24  */
  25
  26 #include <errno.h>
  27 #include <gpxe/uaccess.h>
  28 #include <gpxe/memmap.h>
  29 #include <gpxe/segment.h>
  30
  31 /**
  32  * Prepare segment for loading
  33  *
  34  * @v segment           Segment start
  35  * @v filesz            Size of the "allocated bytes" portion of the segment
  36  * @v memsz             Size of the segment
  37  * @ret rc              Return status code
  38  */
  39 int prep_segment ( userptr_t segment, size_t filesz, size_t memsz ) {
  40         struct memory_map memmap;
  41         physaddr_t start = user_to_phys ( segment, 0 );
  42         physaddr_t mid = user_to_phys ( segment, filesz );
  43         physaddr_t end = user_to_phys ( segment, memsz );
  44         unsigned int i;
  45
  46         DBG ( "Preparing segment [%lx,%lx,%lx)\n", start, mid, end );
  47
  48         /* Sanity check */
  49         if ( filesz > memsz ) {
  50                 DBG ( "Insane segment [%lx,%lx,%lx)\n", start, mid, end );
  51                 return -EINVAL;
  52         }
  53
  54         /* Get a fresh memory map.  This allows us to automatically
  55          * avoid treading on any regions that Etherboot is currently
  56          * editing out of the memory map.
  57          */
  58         get_memmap ( &memmap );
  59
  60         /* Look for a suitable memory region */
  61         for ( i = 0 ; i < memmap.count ; i++ ) {
  62                 if ( ( start >= memmap.regions[i].start ) &&
  63                      ( end <= memmap.regions[i].end ) ) {
  64                         /* Found valid region: zero bss and return */
  65                         memset_user ( segment, filesz, 0, ( memsz - filesz ) );
  66                         return 0;
  67                 }
  68         }
  69
  70         /* No suitable memory region found */
  71         DBG ( "Segment [%lx,%lx,%lx) does not fit into available memory\n",
  72               start, mid, end );
  73         return -ERANGE;
  74 }