text: /*
   *  GRUB  --  GRand Unified Bootloader
   *  Copyright (C) 2009-2013  Free Software Foundation, Inc.
   *
   *  GRUB is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  GRUB is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  #include <grub/mm.h>
  #include <grub/misc.h>
  
  #include <grub/types.h>
  #include <grub/err.h>
  #include <grub/term.h>
  
  #include <grub/relocator.h>
  #include <grub/relocator_private.h>
  
  extern grub_uint8_t grub_relocator_forward_start;
  extern grub_uint8_t grub_relocator_forward_end;
  extern grub_uint8_t grub_relocator_backward_start;
  extern grub_uint8_t grub_relocator_backward_end;
  
  extern void *grub_relocator_backward_dest;
  extern void *grub_relocator_backward_src;
  extern grub_size_t grub_relocator_backward_chunk_size;
  
  extern void *grub_relocator_forward_dest;
  extern void *grub_relocator_forward_src;
  extern grub_size_t grub_relocator_forward_chunk_size;
  
  #define RELOCATOR_SIZEOF(x)	(&grub_relocator##x##_end - &grub_relocator##x##_start)
  
  grub_size_t grub_relocator_align = 1;
  grub_size_t grub_relocator_forward_size;
  grub_size_t grub_relocator_backward_size;
  #ifdef __x86_64__
  grub_size_t grub_relocator_jumper_size = 12;
  #else
  grub_size_t grub_relocator_jumper_size = 7;
  #endif
  
  void
  grub_cpu_relocator_init (void)
  {
    grub_relocator_forward_size = RELOCATOR_SIZEOF (_forward);
    grub_relocator_backward_size = RELOCATOR_SIZEOF (_backward);
  }
  
  void
  grub_cpu_relocator_jumper (void *rels, grub_addr_t addr)
  {
    grub_uint8_t *ptr;
    ptr = rels;
  #ifdef __x86_64__
    /* movq imm64, %rax (for relocator) */
    *(grub_uint8_t *) ptr = 0x48;
    ptr++;
    *(grub_uint8_t *) ptr = 0xb8;
    ptr++;
    *(grub_uint64_t *) ptr = addr;
    ptr += sizeof (grub_uint64_t);
  #else
    /* movl imm32, %eax (for relocator) */
    *(grub_uint8_t *) ptr = 0xb8;
    ptr++;
    *(grub_uint32_t *) ptr = addr;
    ptr += sizeof (grub_uint32_t);
  #endif
    /* jmp $eax/$rax */
    *(grub_uint8_t *) ptr = 0xff;
    ptr++;
    *(grub_uint8_t *) ptr = 0xe0;
    ptr++;
  }
  
  void
  grub_cpu_relocator_backward (void *ptr, void *src, void *dest,
  			     grub_size_t size)
  {
    grub_relocator_backward_dest = dest;
    grub_relocator_backward_src = src;
    grub_relocator_backward_chunk_size = size;
  
    grub_memmove (ptr,
  		&grub_relocator_backward_start, RELOCATOR_SIZEOF (_backward));
  }
  
  void
  grub_cpu_relocator_forward (void *ptr, void *src, void *dest,
  			    grub_size_t size)
  {
    grub_relocator_forward_dest = dest;
    grub_relocator_forward_src = src;
    grub_relocator_forward_chunk_size = size;
  
    grub_memmove (ptr,
  		&grub_relocator_forward_start, RELOCATOR_SIZEOF (_forward));
  }
  