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      1 /* common.c - miscellaneous shared variables and routines */
      2 /*
      3  *  GRUB  --  GRand Unified Bootloader
      4  *  Copyright (C) 1999,2000,2001,2002,2004  Free Software Foundation, Inc.
      5  *
      6  *  This program is free software; you can redistribute it and/or modify
      7  *  it under the terms of the GNU General Public License as published by
      8  *  the Free Software Foundation; either version 2 of the License, or
      9  *  (at your option) any later version.
     10  *
     11  *  This program is distributed in the hope that it will be useful,
     12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
     13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     14  *  GNU General Public License for more details.
     15  *
     16  *  You should have received a copy of the GNU General Public License
     17  *  along with this program; if not, write to the Free Software
     18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
     19  */
     20 
     21 #include <shared.h>
     22 
     23 #ifdef SUPPORT_DISKLESS
     24 # define GRUB	1
     25 # include <etherboot.h>
     26 #endif
     27 
     28 /*
     29  *  Shared BIOS/boot data.
     30  */
     31 
     32 struct multiboot_info mbi;
     33 unsigned long saved_drive;
     34 unsigned long saved_partition;
     35 unsigned long cdrom_drive;
     36 #ifndef STAGE1_5
     37 unsigned long saved_mem_upper;
     38 
     39 /* This saves the maximum size of extended memory (in KB).  */
     40 unsigned long extended_memory;
     41 #endif
     42 
     43 /*
     44  *  Error code stuff.
     45  */
     46 
     47 grub_error_t errnum = ERR_NONE;
     48 
     49 #ifndef STAGE1_5
     50 
     51 char *err_list[] =
     52 {
     53   [ERR_NONE] = 0,
     54   [ERR_BAD_ARGUMENT] = "Invalid argument",
     55   [ERR_BAD_FILENAME] =
     56   "Filename must be either an absolute pathname or blocklist",
     57   [ERR_BAD_FILETYPE] = "Bad file or directory type",
     58   [ERR_BAD_GZIP_DATA] = "Bad or corrupt data while decompressing file",
     59   [ERR_BAD_GZIP_HEADER] = "Bad or incompatible header in compressed file",
     60   [ERR_BAD_PART_TABLE] = "Partition table invalid or corrupt",
     61   [ERR_BAD_VERSION] = "Mismatched or corrupt version of stage1/stage2",
     62   [ERR_BELOW_1MB] = "Loading below 1MB is not supported",
     63   [ERR_BOOT_COMMAND] = "Kernel must be loaded before booting",
     64   [ERR_BOOT_FAILURE] = "Unknown boot failure",
     65   [ERR_BOOT_FEATURES] = "Unsupported Multiboot features requested",
     66   [ERR_DEV_FORMAT] = "Unrecognized device string",
     67   [ERR_DEV_NEED_INIT] = "Device not initialized yet",
     68   [ERR_DEV_VALUES] = "Invalid device requested",
     69   [ERR_EXEC_FORMAT] = "Invalid or unsupported executable format",
     70   [ERR_FILELENGTH] =
     71   "Filesystem compatibility error, cannot read whole file",
     72   [ERR_FILE_NOT_FOUND] = "File not found",
     73   [ERR_FSYS_CORRUPT] = "Inconsistent filesystem structure",
     74   [ERR_FSYS_MOUNT] = "Cannot mount selected partition",
     75   [ERR_GEOM] = "Selected cylinder exceeds maximum supported by BIOS",
     76   [ERR_NEED_LX_KERNEL] = "Linux kernel must be loaded before initrd",
     77   [ERR_NEED_MB_KERNEL] = "Multiboot kernel must be loaded before modules",
     78   [ERR_NO_DISK] = "Selected disk does not exist",
     79   [ERR_NO_DISK_SPACE] = "No spare sectors on the disk",
     80   [ERR_NO_PART] = "No such partition",
     81   [ERR_NUMBER_OVERFLOW] = "Overflow while parsing number",
     82   [ERR_NUMBER_PARSING] = "Error while parsing number",
     83   [ERR_OUTSIDE_PART] = "Attempt to access block outside partition",
     84   [ERR_PRIVILEGED] = "Must be authenticated",
     85   [ERR_READ] = "Disk read error",
     86   [ERR_SYMLINK_LOOP] = "Too many symbolic links",
     87   [ERR_UNALIGNED] = "File is not sector aligned",
     88   [ERR_UNRECOGNIZED] = "Unrecognized command",
     89   [ERR_WONT_FIT] = "Selected item cannot fit into memory",
     90   [ERR_WRITE] = "Disk write error",
     91 };
     92 
     93 
     94 /* static for BIOS memory map fakery */
     95 static struct AddrRangeDesc fakemap[3] =
     96 {
     97   {20, 0, 0, MB_ARD_MEMORY},
     98   {20, 0x100000, 0, MB_ARD_MEMORY},
     99   {20, 0x1000000, 0, MB_ARD_MEMORY}
    100 };
    101 
    102 /* A big problem is that the memory areas aren't guaranteed to be:
    103    (1) contiguous, (2) sorted in ascending order, or (3) non-overlapping.
    104    Thus this kludge.  */
    105 static unsigned long
    106 mmap_avail_at (unsigned long bottom)
    107 {
    108   unsigned long long top;
    109   unsigned long addr;
    110   int cont;
    111 
    112   top = bottom;
    113   do
    114     {
    115       for (cont = 0, addr = mbi.mmap_addr;
    116 	   addr < mbi.mmap_addr + mbi.mmap_length;
    117 	   addr += *((unsigned long *) addr) + 4)
    118 	{
    119 	  struct AddrRangeDesc *desc = (struct AddrRangeDesc *) addr;
    120 
    121 	  if (desc->Type == MB_ARD_MEMORY
    122 	      && desc->BaseAddr <= top
    123 	      && desc->BaseAddr + desc->Length > top)
    124 	    {
    125 	      top = desc->BaseAddr + desc->Length;
    126 	      cont++;
    127 	    }
    128 	}
    129     }
    130   while (cont);
    131 
    132   /* For now, GRUB assumes 32bits addresses, so...  */
    133   if (top > 0xFFFFFFFF)
    134     top = 0xFFFFFFFF;
    135 
    136   return (unsigned long) top - bottom;
    137 }
    138 #endif /* ! STAGE1_5 */
    139 
    140 /* This queries for BIOS information.  */
    141 void
    142 init_bios_info (void)
    143 {
    144 #ifndef STAGE1_5
    145   unsigned long cont, memtmp, addr;
    146   int drive;
    147 #endif
    148 
    149   /*
    150    *  Get information from BIOS on installed RAM.
    151    */
    152 
    153   mbi.mem_lower = get_memsize (0);
    154   mbi.mem_upper = get_memsize (1);
    155 
    156 #ifndef STAGE1_5
    157   /*
    158    *  We need to call this somewhere before trying to put data
    159    *  above 1 MB, since without calling it, address line 20 will be wired
    160    *  to 0.  Not too desirable.
    161    */
    162 
    163   gateA20 (1);
    164 
    165   /* Store the size of extended memory in EXTENDED_MEMORY, in order to
    166      tell it to non-Multiboot OSes.  */
    167   extended_memory = mbi.mem_upper;
    168 
    169   /*
    170    *  The "mbi.mem_upper" variable only recognizes upper memory in the
    171    *  first memory region.  If there are multiple memory regions,
    172    *  the rest are reported to a Multiboot-compliant OS, but otherwise
    173    *  unused by GRUB.
    174    */
    175 
    176   addr = get_code_end ();
    177   mbi.mmap_addr = addr;
    178   mbi.mmap_length = 0;
    179   cont = 0;
    180 
    181   do
    182     {
    183       cont = get_mmap_entry ((void *) addr, cont);
    184 
    185       /* If the returned buffer's length is zero, quit. */
    186       if (! *((unsigned long *) addr))
    187 	break;
    188 
    189       mbi.mmap_length += *((unsigned long *) addr) + 4;
    190       addr += *((unsigned long *) addr) + 4;
    191     }
    192   while (cont);
    193 
    194   if (mbi.mmap_length)
    195     {
    196       unsigned long long max_addr;
    197 
    198       /*
    199        *  This is to get the lower memory, and upper memory (up to the
    200        *  first memory hole), into the "mbi.mem_{lower,upper}"
    201        *  elements.  This is for OS's that don't care about the memory
    202        *  map, but might care about total RAM available.
    203        */
    204       mbi.mem_lower = mmap_avail_at (0) >> 10;
    205       mbi.mem_upper = mmap_avail_at (0x100000) >> 10;
    206 
    207       /* Find the maximum available address. Ignore any memory holes.  */
    208       for (max_addr = 0, addr = mbi.mmap_addr;
    209 	   addr < mbi.mmap_addr + mbi.mmap_length;
    210 	   addr += *((unsigned long *) addr) + 4)
    211 	{
    212 	  struct AddrRangeDesc *desc = (struct AddrRangeDesc *) addr;
    213 
    214 	  if (desc->Type == MB_ARD_MEMORY && desc->Length > 0
    215 	      && desc->BaseAddr + desc->Length > max_addr)
    216 	    max_addr = desc->BaseAddr + desc->Length;
    217 	}
    218 
    219       extended_memory = (max_addr - 0x100000) >> 10;
    220     }
    221   else if ((memtmp = get_eisamemsize ()) != -1)
    222     {
    223       cont = memtmp & ~0xFFFF;
    224       memtmp = memtmp & 0xFFFF;
    225 
    226       if (cont != 0)
    227 	extended_memory = (cont >> 10) + 0x3c00;
    228       else
    229 	extended_memory = memtmp;
    230 
    231       if (!cont || (memtmp == 0x3c00))
    232 	memtmp += (cont >> 10);
    233       else
    234 	{
    235 	  /* XXX should I do this at all ??? */
    236 
    237 	  mbi.mmap_addr = (unsigned long) fakemap;
    238 	  mbi.mmap_length = sizeof (fakemap);
    239 	  fakemap[0].Length = (mbi.mem_lower << 10);
    240 	  fakemap[1].Length = (memtmp << 10);
    241 	  fakemap[2].Length = cont;
    242 	}
    243 
    244       mbi.mem_upper = memtmp;
    245     }
    246 
    247   saved_mem_upper = mbi.mem_upper;
    248 
    249   /* Get the drive info.  */
    250   /* FIXME: This should be postponed until a Multiboot kernel actually
    251      requires it, because this could slow down the start-up
    252      unreasonably.  */
    253   mbi.drives_length = 0;
    254   mbi.drives_addr = addr;
    255 
    256   /* For now, GRUB doesn't probe floppies, since it is trivial to map
    257      floppy drives to BIOS drives.  */
    258   for (drive = 0x80; drive < 0x88; drive++)
    259     {
    260       struct geometry geom;
    261       struct drive_info *info = (struct drive_info *) addr;
    262       unsigned short *port;
    263 
    264       /* Get the geometry. This ensures that the drive is present.  */
    265       if (get_diskinfo (drive, &geom))
    266 	break;
    267 
    268       /* Clean out the I/O map.  */
    269       grub_memset ((char *) io_map, 0,
    270 		   IO_MAP_SIZE * sizeof (unsigned short));
    271 
    272       /* Disable to probe I/O ports temporarily, because this doesn't
    273 	 work with some BIOSes (maybe they are too buggy).  */
    274 #if 0
    275       /* Track the int13 handler.  */
    276       track_int13 (drive);
    277 #endif
    278 
    279       /* Set the information.  */
    280       info->drive_number = drive;
    281       info->drive_mode = ((geom.flags & BIOSDISK_FLAG_LBA_EXTENSION)
    282 			  ? MB_DI_LBA_MODE : MB_DI_CHS_MODE);
    283       info->drive_cylinders = geom.cylinders;
    284       info->drive_heads = geom.heads;
    285       info->drive_sectors = geom.sectors;
    286 
    287       addr += sizeof (struct drive_info);
    288       for (port = io_map; *port; port++, addr += sizeof (unsigned short))
    289 	*((unsigned short *) addr) = *port;
    290 
    291       info->size = addr - (unsigned long) info;
    292       mbi.drives_length += info->size;
    293     }
    294 
    295   /* Get the ROM configuration table by INT 15, AH=C0h.  */
    296   mbi.config_table = get_rom_config_table ();
    297 
    298   /* Set the boot loader name.  */
    299   mbi.boot_loader_name = (unsigned long) "GNU GRUB " VERSION;
    300 
    301   /* Get the APM BIOS table.  */
    302   get_apm_info ();
    303   if (apm_bios_info.version)
    304     mbi.apm_table = (unsigned long) &apm_bios_info;
    305 
    306   /*
    307    *  Initialize other Multiboot Info flags.
    308    */
    309 
    310   mbi.flags = (MB_INFO_MEMORY | MB_INFO_CMDLINE | MB_INFO_BOOTDEV
    311 	       | MB_INFO_DRIVE_INFO | MB_INFO_CONFIG_TABLE
    312 	       | MB_INFO_BOOT_LOADER_NAME);
    313 
    314   if (apm_bios_info.version)
    315     mbi.flags |= MB_INFO_APM_TABLE;
    316 
    317 #endif /* STAGE1_5 */
    318 
    319   /* Set boot drive and partition.  */
    320   saved_drive = boot_drive;
    321   saved_partition = install_partition;
    322 
    323   /* Set cdrom drive.  */
    324   {
    325     struct geometry geom;
    326 
    327     /* Get the geometry.  */
    328     if (get_diskinfo (boot_drive, &geom)
    329 	|| ! (geom.flags & BIOSDISK_FLAG_CDROM))
    330       cdrom_drive = GRUB_INVALID_DRIVE;
    331     else
    332       cdrom_drive = boot_drive;
    333   }
    334 
    335   /* Start main routine here.  */
    336   cmain ();
    337 }
    338