kern/i386/qemu/mmap.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/machine/init.h>
  20 #include <grub/machine/memory.h>
  21 #include <grub/machine/boot.h>
  22 #include <grub/types.h>
  23 #include <grub/err.h>
  24 #include <grub/misc.h>
  25 #include <grub/cmos.h>
  26
  27 #define QEMU_CMOS_MEMSIZE_HIGH          0x35
  28 #define QEMU_CMOS_MEMSIZE_LOW           0x34
  29
  30 #define min(a,b)        ((a) > (b) ? (b) : (a))
  31
  32 extern char _start[];
  33 extern char _end[];
  34
  35 grub_size_t grub_lower_mem, grub_upper_mem;
  36 grub_uint64_t mem_size;
  37
  38 void
  39 grub_machine_mmap_init ()
  40 {
  41   mem_size = grub_cmos_read (QEMU_CMOS_MEMSIZE_HIGH) << 24 | grub_cmos_read (QEMU_CMOS_MEMSIZE_LOW) << 16;
  42
  43   /* Don't ask... */
  44   mem_size += (16 * 1024 * 1024);
  45 }
  46
  47 grub_err_t
  48 grub_machine_mmap_iterate (int NESTED_FUNC_ATTR (*hook) (grub_uint64_t, grub_uint64_t, grub_uint32_t))
  49 {
  50   if (hook (0x0,
  51             (grub_addr_t) _start,
  52             GRUB_MACHINE_MEMORY_AVAILABLE))
  53     return 1;
  54
  55   if (hook (GRUB_MEMORY_MACHINE_UPPER,
  56             0x100000 - GRUB_MEMORY_MACHINE_UPPER,
  57             GRUB_MACHINE_MEMORY_RESERVED))
  58     return 1;
  59
  60   /* Protect boot.img, which contains the gdt.  It is mapped at the top of memory
  61      (it is also mapped below 0x100000, but we already reserved that area).  */
  62   if (hook ((grub_uint32_t) -GRUB_BOOT_MACHINE_SIZE,
  63             GRUB_BOOT_MACHINE_SIZE,
  64             GRUB_MACHINE_MEMORY_RESERVED))
  65     return 1;
  66
  67   /* Everything else is free.  */
  68   if (hook (0x100000,
  69             min (mem_size, (grub_uint32_t) -GRUB_BOOT_MACHINE_SIZE) - 0x100000,
  70             GRUB_MACHINE_MEMORY_AVAILABLE))
  71     return 1;
  72
  73   return 0;
  74 }