kern/i386/pc/init.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 2002,2003,2004,2005,2006,2007,2008,2009,2010  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/kernel.h>
  20 #include <grub/mm.h>
  21 #include <grub/machine/boot.h>
  22 #include <grub/machine/init.h>
  23 #include <grub/machine/memory.h>
  24 #include <grub/machine/console.h>
  25 #include <grub/machine/kernel.h>
  26 #include <grub/types.h>
  27 #include <grub/err.h>
  28 #include <grub/dl.h>
  29 #include <grub/misc.h>
  30 #include <grub/loader.h>
  31 #include <grub/env.h>
  32 #include <grub/cache.h>
  33 #include <grub/time.h>
  34 #include <grub/cpu/tsc.h>
  35
  36 struct mem_region
  37 {
  38   grub_addr_t addr;
  39   grub_size_t size;
  40 };
  41
  42 #define MAX_REGIONS     32
  43
  44 static struct mem_region mem_regions[MAX_REGIONS];
  45 static int num_regions;
  46
  47 grub_addr_t grub_os_area_addr;
  48 grub_size_t grub_os_area_size;
  49
  50 static char *
  51 make_install_device (void)
  52 {
  53   /* XXX: This should be enough.  */
  54   char dev[100], *ptr = dev;
  55
  56   if (grub_prefix[0] != '(')
  57     {
  58       /* No hardcoded root partition - make it from the boot drive and the
  59          partition number encoded at the install time.  */
  60       if (grub_boot_drive == GRUB_BOOT_MACHINE_PXE_DL)
  61         {
  62           grub_strcpy (dev, "(pxe");
  63           ptr += sizeof ("(pxe") - 1;
  64         }
  65       else
  66         {
  67           grub_snprintf (dev, sizeof (dev),
  68                          "(%cd%u", (grub_boot_drive & 0x80) ? 'h' : 'f',
  69                          grub_boot_drive & 0x7f);
  70           ptr += grub_strlen (ptr);
  71
  72           if (grub_install_dos_part >= 0)
  73             grub_snprintf (ptr, sizeof (dev) - (ptr - dev),
  74                            ",%u", grub_install_dos_part + 1);
  75           ptr += grub_strlen (ptr);
  76
  77           if (grub_install_bsd_part >= 0)
  78             grub_snprintf (ptr, sizeof (dev) - (ptr - dev), ",%c",
  79                            grub_install_bsd_part + 'a');
  80           ptr += grub_strlen (ptr);
  81         }
  82
  83       grub_snprintf (ptr, sizeof (dev) - (ptr - dev), ")%s", grub_prefix);
  84       grub_strcpy (grub_prefix, dev);
  85     }
  86
  87   return grub_prefix;
  88 }
  89
  90 /* Add a memory region.  */
  91 static void
  92 add_mem_region (grub_addr_t addr, grub_size_t size)
  93 {
  94   if (num_regions == MAX_REGIONS)
  95     /* Ignore.  */
  96     return;
  97
  98   mem_regions[num_regions].addr = addr;
  99   mem_regions[num_regions].size = size;
 100   num_regions++;
 101 }
 102
 103 /* Compact memory regions.  */
 104 static void
 105 compact_mem_regions (void)
 106 {
 107   int i, j;
 108
 109   /* Sort them.  */
 110   for (i = 0; i < num_regions - 1; i++)
 111     for (j = i + 1; j < num_regions; j++)
 112       if (mem_regions[i].addr > mem_regions[j].addr)
 113         {
 114           struct mem_region tmp = mem_regions[i];
 115           mem_regions[i] = mem_regions[j];
 116           mem_regions[j] = tmp;
 117         }
 118
 119   /* Merge overlaps.  */
 120   for (i = 0; i < num_regions - 1; i++)
 121     if (mem_regions[i].addr + mem_regions[i].size >= mem_regions[i + 1].addr)
 122       {
 123         j = i + 1;
 124
 125         if (mem_regions[i].addr + mem_regions[i].size
 126             < mem_regions[j].addr + mem_regions[j].size)
 127           mem_regions[i].size = (mem_regions[j].addr + mem_regions[j].size
 128                                  - mem_regions[i].addr);
 129
 130         grub_memmove (mem_regions + j, mem_regions + j + 1,
 131                       (num_regions - j - 1) * sizeof (struct mem_region));
 132         i--;
 133         num_regions--;
 134       }
 135 }
 136
 137 void
 138 grub_machine_init (void)
 139 {
 140   int i;
 141   int grub_lower_mem;
 142
 143   /* Initialize the console as early as possible.  */
 144   grub_console_init ();
 145
 146   grub_lower_mem = grub_get_memsize (0) << 10;
 147
 148   /* Sanity check.  */
 149   if (grub_lower_mem < GRUB_MEMORY_MACHINE_RESERVED_END)
 150     grub_fatal ("too small memory");
 151
 152 #if 0
 153   /* Turn on Gate A20 to access >1MB.  */
 154   grub_gate_a20 (1);
 155 #endif
 156
 157 /* FIXME: This prevents loader/i386/linux.c from using low memory.  When our
 158    heap implements support for requesting a chunk in low memory, this should
 159    no longer be a problem.  */
 160 #if 0
 161   /* Add the lower memory into free memory.  */
 162   if (grub_lower_mem >= GRUB_MEMORY_MACHINE_RESERVED_END)
 163     add_mem_region (GRUB_MEMORY_MACHINE_RESERVED_END,
 164                     grub_lower_mem - GRUB_MEMORY_MACHINE_RESERVED_END);
 165 #endif
 166
 167   auto int NESTED_FUNC_ATTR hook (grub_uint64_t, grub_uint64_t, grub_uint32_t);
 168   int NESTED_FUNC_ATTR hook (grub_uint64_t addr, grub_uint64_t size, grub_uint32_t type)
 169     {
 170       /* Avoid the lower memory.  */
 171       if (addr < 0x100000)
 172         {
 173           if (size <= 0x100000 - addr)
 174             return 0;
 175
 176           size -= 0x100000 - addr;
 177           addr = 0x100000;
 178         }
 179
 180       /* Ignore >4GB.  */
 181       if (addr <= 0xFFFFFFFF && type == GRUB_MACHINE_MEMORY_AVAILABLE)
 182         {
 183           grub_size_t len;
 184
 185           len = (grub_size_t) ((addr + size > 0xFFFFFFFF)
 186                  ? 0xFFFFFFFF - addr
 187                  : size);
 188           add_mem_region (addr, len);
 189         }
 190
 191       return 0;
 192     }
 193
 194   grub_machine_mmap_iterate (hook);
 195
 196   compact_mem_regions ();
 197
 198   /* Add the memory regions to free memory, except for the region starting
 199      from 1MB. This region is partially used for loading OS images.
 200      For now, 1/4 of this is added to free memory.  */
 201   for (i = 0; i < num_regions; i++)
 202     if (mem_regions[i].addr == 0x100000)
 203       {
 204         grub_size_t quarter = mem_regions[i].size >> 2;
 205
 206         grub_os_area_addr = mem_regions[i].addr;
 207         grub_os_area_size = mem_regions[i].size - quarter;
 208         grub_mm_init_region ((void *) (grub_os_area_addr + grub_os_area_size),
 209                              quarter);
 210       }
 211     else
 212       grub_mm_init_region ((void *) mem_regions[i].addr, mem_regions[i].size);
 213
 214   if (! grub_os_area_addr)
 215     grub_fatal ("no upper memory");
 216
 217   grub_tsc_init ();
 218 }
 219
 220 void
 221 grub_machine_set_prefix (void)
 222 {
 223   /* Initialize the prefix.  */
 224   grub_env_set ("prefix", make_install_device ());
 225 }
 226
 227 void
 228 grub_machine_fini (void)
 229 {
 230   grub_console_fini ();
 231   grub_stop_floppy ();
 232 }
 233
 234 /* Return the end of the core image.  */
 235 grub_addr_t
 236 grub_arch_modules_addr (void)
 237 {
 238   return GRUB_MEMORY_MACHINE_DECOMPRESSION_ADDR
 239     + (grub_kernel_image_size - GRUB_KERNEL_MACHINE_RAW_SIZE);
 240 }