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 FILE_LICENCE ( GPL2_OR_LATER );
  20
  21 /**
  22  * @file
  23  *
  24  * Executable image segments
  25  *
  26  */
  27
  28 #include <errno.h>
  29 #include <gpxe/uaccess.h>
  30 #include <gpxe/memmap.h>
  31 #include <gpxe/errortab.h>
  32 #include <gpxe/segment.h>
  33
  34 /**
  35  * Segment-specific error messages
  36  *
  37  * This error happens sufficiently often to merit a user-friendly
  38  * description.
  39  */
  40 #define ERANGE_SEGMENT __einfo_error ( EINFO_ERANGE_SEGMENT )
  41 #define EINFO_ERANGE_SEGMENT \
  42         __einfo_uniqify ( EINFO_ERANGE, 0x01, "Requested memory not available" )
  43 struct errortab segment_errors[] __errortab = {
  44         __einfo_errortab ( EINFO_ERANGE_SEGMENT ),
  45 };
  46
  47 /**
  48  * Prepare segment for loading
  49  *
  50  * @v segment           Segment start
  51  * @v filesz            Size of the "allocated bytes" portion of the segment
  52  * @v memsz             Size of the segment
  53  * @ret rc              Return status code
  54  */
  55 int prep_segment ( userptr_t segment, size_t filesz, size_t memsz ) {
  56         struct memory_map memmap;
  57         physaddr_t start = user_to_phys ( segment, 0 );
  58         physaddr_t mid = user_to_phys ( segment, filesz );
  59         physaddr_t end = user_to_phys ( segment, memsz );
  60         unsigned int i;
  61
  62         DBG ( "Preparing segment [%lx,%lx,%lx)\n", start, mid, end );
  63
  64         /* Sanity check */
  65         if ( filesz > memsz ) {
  66                 DBG ( "Insane segment [%lx,%lx,%lx)\n", start, mid, end );
  67                 return -EINVAL;
  68         }
  69
  70         /* Get a fresh memory map.  This allows us to automatically
  71          * avoid treading on any regions that Etherboot is currently
  72          * editing out of the memory map.
  73          */
  74         get_memmap ( &memmap );
  75
  76         /* Look for a suitable memory region */
  77         for ( i = 0 ; i < memmap.count ; i++ ) {
  78                 if ( ( start >= memmap.regions[i].start ) &&
  79                      ( end <= memmap.regions[i].end ) ) {
  80                         /* Found valid region: zero bss and return */
  81                         memset_user ( segment, filesz, 0, ( memsz - filesz ) );
  82                         return 0;
  83                 }
  84         }
  85
  86         /* No suitable memory region found */
  87         DBG ( "Segment [%lx,%lx,%lx) does not fit into available memory\n",
  88               start, mid, end );
  89         return -ERANGE_SEGMENT;
  90 }