loader/xnu_resume.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/normal.h>
  20 #include <grub/dl.h>
  21 #include <grub/file.h>
  22 #include <grub/disk.h>
  23 #include <grub/misc.h>
  24 #include <grub/xnu.h>
  25 #include <grub/cpu/xnu.h>
  26 #include <grub/mm.h>
  27 #include <grub/loader.h>
  28
  29 static void *grub_xnu_hibernate_image;
  30
  31 static grub_err_t
  32 grub_xnu_resume_unload (void)
  33 {
  34   /* Free loaded image */
  35   if (grub_xnu_hibernate_image)
  36     grub_free (grub_xnu_hibernate_image);
  37   grub_xnu_hibernate_image = 0;
  38   grub_xnu_unlock ();
  39   return GRUB_ERR_NONE;
  40 }
  41
  42 grub_err_t
  43 grub_xnu_resume (char *imagename)
  44 {
  45   grub_file_t file;
  46   grub_size_t total_header_size;
  47   struct grub_xnu_hibernate_header hibhead;
  48   char *buf, *codetmp;
  49
  50   grub_uint32_t codedest;
  51   grub_uint32_t codesize;
  52
  53   file = grub_file_open (imagename);
  54   if (! file)
  55     return 0;
  56
  57   /* Read the header. */
  58   if (grub_file_read (file, &hibhead, sizeof (hibhead))
  59       !=sizeof (hibhead))
  60     {
  61       grub_file_close (file);
  62       return grub_error (GRUB_ERR_READ_ERROR,
  63                          "cannot read the hibernate header");
  64     }
  65
  66   /* Check the header. */
  67   if (hibhead.magic != GRUB_XNU_HIBERNATE_MAGIC)
  68     {
  69       grub_file_close (file);
  70       return grub_error (GRUB_ERR_BAD_OS,
  71                          "hibernate header has incorrect magic number");
  72     }
  73   if (hibhead.encoffset)
  74     {
  75       grub_file_close (file);
  76       return grub_error (GRUB_ERR_BAD_OS,
  77                          "encrypted images aren't supported yet");
  78     }
  79
  80   codedest = hibhead.launchcode_target_page;
  81   codedest *= GRUB_XNU_PAGESIZE;
  82   codesize = hibhead.launchcode_numpages;
  83   codesize *= GRUB_XNU_PAGESIZE;
  84
  85   /* FIXME: check that codedest..codedest+codesize is available. */
  86
  87   /* Calculate total size before pages to copy. */
  88   total_header_size = hibhead.extmapsize + sizeof (hibhead);
  89
  90   /* Unload image if any. */
  91   if (grub_xnu_hibernate_image)
  92     grub_free (grub_xnu_hibernate_image);
  93
  94   /* Try to allocate necessary space.
  95      FIXME: mm isn't good enough yet to handle huge allocations.
  96    */
  97   grub_xnu_hibernate_image = buf = grub_malloc (hibhead.image_size);
  98   if (! buf)
  99     {
 100       grub_file_close (file);
 101       return grub_error (GRUB_ERR_OUT_OF_MEMORY,
 102                          "not enough memory to load image");
 103     }
 104
 105   /* Read image. */
 106   if (grub_file_seek (file, 0) == (grub_off_t)-1
 107       || grub_file_read (file, buf, hibhead.image_size)
 108       != (grub_ssize_t) hibhead.image_size)
 109     {
 110       grub_file_close (file);
 111       return grub_error (GRUB_ERR_READ_ERROR, "Cannot read resume image.");
 112     }
 113   grub_file_close (file);
 114
 115   codetmp = grub_memalign (GRUB_XNU_PAGESIZE, codesize + GRUB_XNU_PAGESIZE);
 116   /* Setup variables needed by asm helper. */
 117   grub_xnu_heap_will_be_at = codedest;
 118   grub_xnu_heap_start = codetmp;
 119   grub_xnu_heap_size = codesize;
 120   grub_xnu_stack = (codedest + hibhead.stack);
 121   grub_xnu_entry_point = (codedest + hibhead.entry_point);
 122   grub_xnu_arg1 = (long) buf;
 123
 124   /* Prepare asm helper. */
 125   grub_memcpy (codetmp, ((grub_uint8_t *) buf) + total_header_size, codesize);
 126   grub_memcpy (codetmp + codesize, grub_xnu_launcher_start,
 127                grub_xnu_launcher_end - grub_xnu_launcher_start);
 128
 129   /* We're ready now. */
 130   grub_loader_set ((grub_err_t (*) (void)) (codetmp + codesize),
 131                    grub_xnu_resume_unload, 0);
 132
 133   /* Prevent module from unloading. */
 134   grub_xnu_lock ();
 135   return GRUB_ERR_NONE;
 136 }