arch/all-pc/boot/grub2-aros/grub-core/efiemu/i386/loadcore32.c

   1 /* i386 CPU-specific part of loadcore.c for 32-bit mode */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/err.h>
  21 #include <grub/mm.h>
  22 #include <grub/misc.h>
  23 #include <grub/efiemu/efiemu.h>
  24 #include <grub/cpu/efiemu.h>
  25 #include <grub/elf.h>
  26 #include <grub/i18n.h>
  27
  28 /* Check if EHDR is a valid ELF header.  */
  29 int
  30 grub_arch_efiemu_check_header32 (void *ehdr)
  31 {
  32   Elf32_Ehdr *e = ehdr;
  33
  34   /* Check the magic numbers.  */
  35   return (e->e_ident[EI_CLASS] == ELFCLASS32
  36           && e->e_ident[EI_DATA] == ELFDATA2LSB
  37           && e->e_machine == EM_386);
  38 }
  39
  40 /* Relocate symbols.  */
  41 grub_err_t
  42 grub_arch_efiemu_relocate_symbols32 (grub_efiemu_segment_t segs,
  43                                      struct grub_efiemu_elf_sym *elfsyms,
  44                                      void *ehdr)
  45 {
  46   unsigned i;
  47   Elf32_Ehdr *e = ehdr;
  48   Elf32_Shdr *s;
  49   grub_err_t err;
  50
  51   grub_dprintf ("efiemu", "relocating symbols %d %d\n",
  52                 e->e_shoff, e->e_shnum);
  53
  54   for (i = 0, s = (Elf32_Shdr *) ((char *) e + e->e_shoff);
  55        i < e->e_shnum;
  56        i++, s = (Elf32_Shdr *) ((char *) s + e->e_shentsize))
  57     if (s->sh_type == SHT_REL)
  58       {
  59         grub_efiemu_segment_t seg;
  60         grub_dprintf ("efiemu", "shtrel\n");
  61
  62         /* Find the target segment.  */
  63         for (seg = segs; seg; seg = seg->next)
  64           if (seg->section == s->sh_info)
  65             break;
  66
  67         if (seg)
  68           {
  69             Elf32_Rel *rel, *max;
  70
  71             for (rel = (Elf32_Rel *) ((char *) e + s->sh_offset),
  72                    max = rel + s->sh_size / s->sh_entsize;
  73                  rel < max;
  74                  rel++)
  75               {
  76                 Elf32_Word *addr;
  77                 struct grub_efiemu_elf_sym sym;
  78                 if (seg->size < rel->r_offset)
  79                   return grub_error (GRUB_ERR_BAD_MODULE,
  80                                      "reloc offset is out of the segment");
  81
  82                 addr = (Elf32_Word *)
  83                   ((char *) grub_efiemu_mm_obtain_request (seg->handle)
  84                    + seg->off + rel->r_offset);
  85                 sym = elfsyms[ELF32_R_SYM (rel->r_info)];
  86
  87                 switch (ELF32_R_TYPE (rel->r_info))
  88                   {
  89                   case R_386_32:
  90                     err = grub_efiemu_write_value (addr, sym.off + *addr,
  91                                                    sym.handle, 0,
  92                                                    seg->ptv_rel_needed,
  93                                                    sizeof (grub_uint32_t));
  94                     if (err)
  95                       return err;
  96
  97                     break;
  98
  99                   case R_386_PC32:
 100                     err = grub_efiemu_write_value (addr, sym.off + *addr
 101                                                    - rel->r_offset
 102                                                    - seg->off, sym.handle,
 103                                                    seg->handle,
 104                                                    seg->ptv_rel_needed,
 105                                                    sizeof (grub_uint32_t));
 106                     if (err)
 107                       return err;
 108                     break;
 109                   default:
 110                     return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
 111                                        N_("relocation 0x%x is not implemented yet"),
 112                                        ELF_R_TYPE (rel->r_info));
 113                   }
 114               }
 115           }
 116       }
 117
 118   return GRUB_ERR_NONE;
 119 }
 120
 121