lib/i386/relocator.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2009  Free Software Foundation, Inc.
   4  *
   5  *  GRUB is free software: you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation, either version 3 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  GRUB is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <grub/mm.h>
  20 #include <grub/misc.h>
  21
  22 #include <grub/types.h>
  23 #include <grub/types.h>
  24 #include <grub/err.h>
  25
  26 #include <grub/i386/relocator.h>
  27
  28 extern grub_uint8_t grub_relocator32_forward_start;
  29 extern grub_uint8_t grub_relocator32_forward_end;
  30 extern grub_uint8_t grub_relocator32_backward_start;
  31 extern grub_uint8_t grub_relocator32_backward_end;
  32
  33 extern grub_uint32_t grub_relocator32_backward_dest;
  34 extern grub_uint32_t grub_relocator32_backward_size;
  35 extern grub_addr_t grub_relocator32_backward_src;
  36
  37 extern grub_uint32_t grub_relocator32_forward_dest;
  38 extern grub_uint32_t grub_relocator32_forward_size;
  39 extern grub_addr_t grub_relocator32_forward_src;
  40
  41 extern grub_uint32_t grub_relocator32_forward_eax;
  42 extern grub_uint32_t grub_relocator32_forward_ebx;
  43 extern grub_uint32_t grub_relocator32_forward_ecx;
  44 extern grub_uint32_t grub_relocator32_forward_edx;
  45 extern grub_uint32_t grub_relocator32_forward_eip;
  46 extern grub_uint32_t grub_relocator32_forward_esp;
  47
  48 extern grub_uint32_t grub_relocator32_backward_eax;
  49 extern grub_uint32_t grub_relocator32_backward_ebx;
  50 extern grub_uint32_t grub_relocator32_backward_ecx;
  51 extern grub_uint32_t grub_relocator32_backward_edx;
  52 extern grub_uint32_t grub_relocator32_backward_eip;
  53 extern grub_uint32_t grub_relocator32_backward_esp;
  54
  55 #define RELOCATOR_SIZEOF(x)     (&grub_relocator32_##x##_end - &grub_relocator32_##x##_start)
  56 #define RELOCATOR_ALIGN 16
  57 #define PREFIX(x) grub_relocator32_ ## x
  58
  59 static void
  60 write_call_relocator_bw (void *ptr, void *src, grub_uint32_t dest,
  61                          grub_size_t size, struct grub_relocator32_state state)
  62 {
  63   grub_relocator32_backward_dest = dest;
  64   grub_relocator32_backward_src = PTR_TO_UINT64 (src);
  65   grub_relocator32_backward_size = size;
  66
  67   grub_relocator32_backward_eax = state.eax;
  68   grub_relocator32_backward_ebx = state.ebx;
  69   grub_relocator32_backward_ecx = state.ecx;
  70   grub_relocator32_backward_edx = state.edx;
  71   grub_relocator32_backward_eip = state.eip;
  72   grub_relocator32_backward_esp = state.esp;
  73
  74   grub_memmove (ptr,
  75                 &grub_relocator32_backward_start,
  76                 RELOCATOR_SIZEOF (backward));
  77   ((void (*) (void)) ptr) ();
  78 }
  79
  80 static void
  81 write_call_relocator_fw (void *ptr, void *src, grub_uint32_t dest,
  82                          grub_size_t size, struct grub_relocator32_state state)
  83 {
  84
  85   grub_relocator32_forward_dest = dest;
  86   grub_relocator32_forward_src = PTR_TO_UINT64 (src);
  87   grub_relocator32_forward_size = size;
  88
  89   grub_relocator32_forward_eax = state.eax;
  90   grub_relocator32_forward_ebx = state.ebx;
  91   grub_relocator32_forward_ecx = state.ecx;
  92   grub_relocator32_forward_edx = state.edx;
  93   grub_relocator32_forward_eip = state.eip;
  94   grub_relocator32_forward_esp = state.esp;
  95
  96   grub_memmove (ptr,
  97                 &grub_relocator32_forward_start,
  98                 RELOCATOR_SIZEOF (forward));
  99   ((void (*) (void)) ptr) ();
 100 }
 101
 102 #include "../relocator.c"