kern/i386/multiboot_mmap.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2002,2003,2004,2005,2006,2007,2008  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/machine/init.h>
  20 #include <grub/machine/memory.h>
  21 #include <grub/types.h>
  22 #include <grub/multiboot.h>
  23 #include <grub/err.h>
  24 #include <grub/misc.h>
  25
  26 grub_size_t grub_lower_mem, grub_upper_mem;
  27
  28 /* A pointer to the MBI in its initial location.  */
  29 struct grub_multiboot_info *startup_multiboot_info;
  30
  31 /* The MBI has to be copied to our BSS so that it won't be
  32    overwritten.  This is its final location.  */
  33 static struct grub_multiboot_info kern_multiboot_info;
  34
  35 /* Unfortunately we can't use heap at this point.  But 32 looks like a sane
  36    limit (used by memtest86).  */
  37 static grub_uint8_t mmap_entries[sizeof (struct grub_multiboot_mmap_entry) * 32];
  38
  39 void
  40 grub_machine_mmap_init ()
  41 {
  42   if (! startup_multiboot_info)
  43     grub_fatal ("Must be loaded using Multiboot specification (is this an old version of coreboot?)");
  44
  45   /* Move MBI to a safe place.  */
  46   grub_memmove (&kern_multiboot_info, startup_multiboot_info, sizeof (struct grub_multiboot_info));
  47
  48   if ((kern_multiboot_info.flags & MULTIBOOT_INFO_MEM_MAP) == 0)
  49     grub_fatal ("Missing Multiboot memory information");
  50
  51   /* Move the memory map to a safe place.  */
  52   if (kern_multiboot_info.mmap_length > sizeof (mmap_entries))
  53     {
  54       grub_printf ("WARNING: Memory map size exceeds limit; it will be truncated\n");
  55       kern_multiboot_info.mmap_length = sizeof (mmap_entries);
  56     }
  57   grub_memmove (mmap_entries, (void *) kern_multiboot_info.mmap_addr, kern_multiboot_info.mmap_length);
  58   kern_multiboot_info.mmap_addr = (grub_uint32_t) mmap_entries;
  59
  60   if ((kern_multiboot_info.flags & MULTIBOOT_INFO_MEMORY) == 0)
  61     {
  62       grub_lower_mem = GRUB_MEMORY_MACHINE_LOWER_USABLE;
  63       grub_upper_mem = 0;
  64     }
  65   else
  66     {
  67       grub_lower_mem = kern_multiboot_info.mem_lower * 1024;
  68       grub_upper_mem = kern_multiboot_info.mem_upper * 1024;
  69     }
  70 }
  71
  72 grub_err_t
  73 grub_machine_mmap_iterate (int NESTED_FUNC_ATTR (*hook) (grub_uint64_t, grub_uint64_t, grub_uint32_t))
  74 {
  75   struct grub_multiboot_mmap_entry *entry = (void *) kern_multiboot_info.mmap_addr;
  76
  77   while ((unsigned long) entry < kern_multiboot_info.mmap_addr + kern_multiboot_info.mmap_length)
  78     {
  79       if (hook (entry->addr, entry->len, entry->type))
  80         break;
  81
  82       entry = (void *) ((grub_addr_t) entry + entry->size + sizeof (entry->size));
  83     }
  84
  85   return 0;
  86 }