grub-core/lib/powerpc/relocator.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2009,2010  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 #include <grub/cache.h>
  26
  27 #include <grub/powerpc/relocator.h>
  28 #include <grub/relocator_private.h>
  29
  30 extern grub_uint8_t grub_relocator_forward_start;
  31 extern grub_uint8_t grub_relocator_forward_end;
  32 extern grub_uint8_t grub_relocator_backward_start;
  33 extern grub_uint8_t grub_relocator_backward_end;
  34
  35 #define REGW_SIZEOF (2 * sizeof (grub_uint32_t))
  36 #define JUMP_SIZEOF (sizeof (grub_uint32_t))
  37
  38 #define RELOCATOR_SRC_SIZEOF(x) (&grub_relocator_##x##_end \
  39                                  - &grub_relocator_##x##_start)
  40 #define RELOCATOR_SIZEOF(x)     (RELOCATOR_SRC_SIZEOF(x) \
  41                                  + REGW_SIZEOF * 3)
  42 grub_size_t grub_relocator_align = sizeof (grub_uint32_t);
  43 grub_size_t grub_relocator_forward_size;
  44 grub_size_t grub_relocator_backward_size;
  45 grub_size_t grub_relocator_jumper_size = JUMP_SIZEOF + REGW_SIZEOF;
  46
  47 void
  48 grub_cpu_relocator_init (void)
  49 {
  50   grub_relocator_forward_size = RELOCATOR_SIZEOF(forward);
  51   grub_relocator_backward_size = RELOCATOR_SIZEOF(backward);
  52 }
  53
  54 static void
  55 write_reg (int regn, grub_uint32_t val, void **target)
  56 {
  57   /* lis r, val >> 16  */
  58   *(grub_uint32_t *) *target =
  59     ((0x3c00 | (regn << 5)) << 16) | (val >> 16);
  60   *target = ((grub_uint32_t *) *target) + 1;
  61   /* ori r, r, val & 0xffff. */
  62   *(grub_uint32_t *) *target = (((0x6000 | regn << 5 | regn) << 16)
  63                                 | (val & 0xffff));
  64   *target = ((grub_uint32_t *) *target) + 1;
  65 }
  66
  67 static void
  68 write_jump (void **target)
  69 {
  70   /* blr.  */
  71   *(grub_uint32_t *) *target = 0x4e800020;
  72   *target = ((grub_uint32_t *) *target) + 1;
  73 }
  74
  75 void
  76 grub_cpu_relocator_jumper (void *rels, grub_addr_t addr)
  77 {
  78   write_reg (GRUB_PPC_JUMP_REGISTER, addr, &rels);
  79   write_jump (&rels);
  80 }
  81
  82 void
  83 grub_cpu_relocator_backward (void *ptr0, void *src, void *dest,
  84                              grub_size_t size)
  85 {
  86   void *ptr = ptr0;
  87   write_reg (8, (grub_uint32_t) src, &ptr);
  88   write_reg (9, (grub_uint32_t) dest, &ptr);
  89   write_reg (10, (grub_uint32_t) size, &ptr);
  90   grub_memcpy (ptr, &grub_relocator_backward_start,
  91                RELOCATOR_SRC_SIZEOF (backward));
  92 }
  93
  94 void
  95 grub_cpu_relocator_forward (void *ptr0, void *src, void *dest,
  96                              grub_size_t size)
  97 {
  98   void *ptr = ptr0;
  99   write_reg (8, (grub_uint32_t) src, &ptr);
 100   write_reg (9, (grub_uint32_t) dest, &ptr);
 101   write_reg (10, (grub_uint32_t) size, &ptr);
 102   grub_memcpy (ptr, &grub_relocator_forward_start,
 103                RELOCATOR_SRC_SIZEOF (forward));
 104 }
 105
 106 grub_err_t
 107 grub_relocator32_boot (struct grub_relocator *rel,
 108                        struct grub_relocator32_state state)
 109 {
 110   void *ptr;
 111   grub_err_t err;
 112   void *relst;
 113   grub_size_t relsize;
 114   grub_size_t stateset_size = 32 * REGW_SIZEOF + JUMP_SIZEOF;
 115   unsigned i;
 116   grub_relocator_chunk_t ch;
 117
 118   err = grub_relocator_alloc_chunk_align (rel, &ch, 0,
 119                                           (0xffffffff - stateset_size)
 120                                           + 1, stateset_size,
 121                                           sizeof (grub_uint32_t),
 122                                           GRUB_RELOCATOR_PREFERENCE_NONE, 0);
 123   if (err)
 124     return err;
 125
 126   ptr = get_virtual_current_address (ch);
 127   for (i = 0; i < 32; i++)
 128     write_reg (i, state.gpr[i], &ptr);
 129   write_jump (&ptr);
 130
 131   err = grub_relocator_prepare_relocs (rel, get_physical_target_address (ch),
 132                                        &relst, &relsize);
 133   if (err)
 134     return err;
 135
 136   grub_arch_sync_caches ((void *) relst, relsize);
 137
 138   ((void (*) (void)) relst) ();
 139
 140   /* Not reached.  */
 141   return GRUB_ERR_NONE;
 142 }