arch/common/boot/grub2/kern/i386/pc/init.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/kernel.h>
  20 #include <grub/mm.h>
  21 #include <grub/machine/init.h>
  22 #include <grub/machine/memory.h>
  23 #include <grub/machine/console.h>
  24 #include <grub/machine/kernel.h>
  25 #include <grub/types.h>
  26 #include <grub/err.h>
  27 #include <grub/dl.h>
  28 #include <grub/misc.h>
  29 #include <grub/loader.h>
  30 #include <grub/env.h>
  31 #include <grub/cache.h>
  32 #include <grub/time.h>
  33 #include <grub/cpu/tsc.h>
  34
  35 struct mem_region
  36 {
  37   grub_addr_t addr;
  38   grub_size_t size;
  39 };
  40
  41 #define MAX_REGIONS     32
  42
  43 static struct mem_region mem_regions[MAX_REGIONS];
  44 static int num_regions;
  45
  46 grub_addr_t grub_os_area_addr;
  47 grub_size_t grub_os_area_size;
  48 grub_size_t grub_lower_mem, grub_upper_mem;
  49
  50 void
  51 grub_arch_sync_caches (void *address __attribute__ ((unused)),
  52                        grub_size_t len __attribute__ ((unused)))
  53 {
  54 }
  55
  56 static char *
  57 make_install_device (void)
  58 {
  59   /* XXX: This should be enough.  */
  60   char dev[100];
  61
  62   if (grub_prefix[0] != '(')
  63     {
  64       /* If the root drive is not set explicitly, assume that it is identical
  65          to the boot drive.  */
  66       if (grub_root_drive == 0xFF)
  67         grub_root_drive = grub_boot_drive;
  68
  69       grub_sprintf (dev, "(%cd%u", (grub_root_drive & 0x80) ? 'h' : 'f',
  70                     grub_root_drive & 0x7f);
  71
  72       if (grub_install_dos_part >= 0)
  73         grub_sprintf (dev + grub_strlen (dev), ",%u", grub_install_dos_part + 1);
  74
  75       if (grub_install_bsd_part >= 0)
  76         grub_sprintf (dev + grub_strlen (dev), ",%c", grub_install_bsd_part + 'a');
  77
  78       grub_sprintf (dev + grub_strlen (dev), ")%s", grub_prefix);
  79       grub_strcpy (grub_prefix, dev);
  80     }
  81
  82   return grub_prefix;
  83 }
  84
  85 /* Add a memory region.  */
  86 static void
  87 add_mem_region (grub_addr_t addr, grub_size_t size)
  88 {
  89   if (num_regions == MAX_REGIONS)
  90     /* Ignore.  */
  91     return;
  92
  93   mem_regions[num_regions].addr = addr;
  94   mem_regions[num_regions].size = size;
  95   num_regions++;
  96 }
  97
  98 /* Compact memory regions.  */
  99 static void
 100 compact_mem_regions (void)
 101 {
 102   int i, j;
 103
 104   /* Sort them.  */
 105   for (i = 0; i < num_regions - 1; i++)
 106     for (j = i + 1; j < num_regions; j++)
 107       if (mem_regions[i].addr > mem_regions[j].addr)
 108         {
 109           struct mem_region tmp = mem_regions[i];
 110           mem_regions[i] = mem_regions[j];
 111           mem_regions[j] = tmp;
 112         }
 113
 114   /* Merge overlaps.  */
 115   for (i = 0; i < num_regions - 1; i++)
 116     if (mem_regions[i].addr + mem_regions[i].size >= mem_regions[i + 1].addr)
 117       {
 118         j = i + 1;
 119
 120         if (mem_regions[i].addr + mem_regions[i].size
 121             < mem_regions[j].addr + mem_regions[j].size)
 122           mem_regions[i].size = (mem_regions[j].addr + mem_regions[j].size
 123                                  - mem_regions[i].addr);
 124
 125         grub_memmove (mem_regions + j, mem_regions + j + 1,
 126                       (num_regions - j - 1) * sizeof (struct mem_region));
 127         i--;
 128         num_regions--;
 129       }
 130 }
 131
 132 void
 133 grub_machine_init (void)
 134 {
 135   int i;
 136
 137   /* Initialize the console as early as possible.  */
 138   grub_console_init ();
 139
 140   grub_lower_mem = grub_get_memsize (0) << 10;
 141
 142   /* Sanity check.  */
 143   if (grub_lower_mem < GRUB_MEMORY_MACHINE_RESERVED_END)
 144     grub_fatal ("too small memory");
 145
 146 #if 0
 147   /* Turn on Gate A20 to access >1MB.  */
 148   grub_gate_a20 (1);
 149 #endif
 150
 151   /* Add the lower memory into free memory.  */
 152   if (grub_lower_mem >= GRUB_MEMORY_MACHINE_RESERVED_END)
 153     add_mem_region (GRUB_MEMORY_MACHINE_RESERVED_END,
 154                     grub_lower_mem - GRUB_MEMORY_MACHINE_RESERVED_END);
 155
 156   auto int NESTED_FUNC_ATTR hook (grub_uint64_t, grub_uint64_t, grub_uint32_t);
 157   int NESTED_FUNC_ATTR hook (grub_uint64_t addr, grub_uint64_t size, grub_uint32_t type)
 158     {
 159       /* Avoid the lower memory.  */
 160       if (addr < 0x100000)
 161         {
 162           if (size <= 0x100000 - addr)
 163             return 0;
 164
 165           size -= 0x100000 - addr;
 166           addr = 0x100000;
 167         }
 168
 169       /* Ignore >4GB.  */
 170       if (addr <= 0xFFFFFFFF && type == GRUB_MACHINE_MEMORY_AVAILABLE)
 171         {
 172           grub_size_t len;
 173
 174           len = (grub_size_t) ((addr + size > 0xFFFFFFFF)
 175                  ? 0xFFFFFFFF - addr
 176                  : size);
 177           add_mem_region (addr, len);
 178         }
 179
 180       return 0;
 181     }
 182
 183   grub_machine_mmap_iterate (hook);
 184
 185   compact_mem_regions ();
 186
 187   /* Add the memory regions to free memory, except for the region starting
 188      from 1MB. This region is partially used for loading OS images.
 189      For now, 1/4 of this is added to free memory.  */
 190   for (i = 0; i < num_regions; i++)
 191     if (mem_regions[i].addr == 0x100000)
 192       {
 193         grub_size_t quarter = mem_regions[i].size >> 2;
 194
 195         grub_upper_mem = mem_regions[i].size;
 196         grub_os_area_addr = mem_regions[i].addr;
 197         grub_os_area_size = mem_regions[i].size - quarter;
 198         grub_mm_init_region ((void *) (grub_os_area_addr + grub_os_area_size),
 199                              quarter);
 200       }
 201     else
 202       grub_mm_init_region ((void *) mem_regions[i].addr, mem_regions[i].size);
 203
 204   if (! grub_os_area_addr)
 205     grub_fatal ("no upper memory");
 206
 207   grub_tsc_init ();
 208 }
 209
 210 void
 211 grub_machine_set_prefix (void)
 212 {
 213   /* Initialize the prefix.  */
 214   grub_env_set ("prefix", make_install_device ());
 215 }
 216
 217 void
 218 grub_machine_fini (void)
 219 {
 220   grub_console_fini ();
 221 }
 222
 223 /* Return the end of the core image.  */
 224 grub_addr_t
 225 grub_arch_modules_addr (void)
 226 {
 227   return GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR
 228     + (grub_kernel_image_size - GRUB_KERNEL_MACHINE_RAW_SIZE);
 229 }