common.c

grub4dos-0.4.4-2008- 08-src.zip

      unsigned long long max_addr;
      
      /*
       *  This is to get the lower memory, and upper memory (up to the
       *  first memory hole), into the MBI.MEM_{LOWER,UPPER}
       *  elements.  This is for OS's that don't care about the memory
       *  map, but might care about total RAM available.
       */
      saved_mem_lower = mmap_avail_at (0) >> 10;
      saved_mem_upper = mmap_avail_at (0x100000) >> 10;

      /* Find the maximum available address. Ignore any memory holes.  */
      for (max_addr = 0, addr = saved_mmap_addr;
	   addr < saved_mmap_addr + saved_mmap_length;
	   addr += *((unsigned long *) addr) + 4)
	{
	  struct AddrRangeDesc *desc = (struct AddrRangeDesc *) addr;
	  
	  if (desc->Type == MB_ARD_MEMORY && desc->Length > 0
	      && desc->BaseAddr + desc->Length > max_addr)
	    max_addr = desc->BaseAddr + desc->Length;
	}

      extended_memory = (max_addr - 0x100000) >> 10;
    }
  else if ((memtmp = get_eisamemsize ()) != -1)		/* int15/e801 ------safe enough */
    {
      cont = memtmp & ~0xFFFF;
      memtmp = memtmp & 0xFFFF;

      if (cont != 0)
	extended_memory = (cont >> 10) + 0x3c00;
      else
	extended_memory = memtmp;
      
      if (!cont || (memtmp == 0x3c00))
	memtmp += (cont >> 10);
      else
	{
	  /* XXX should I do this at all ??? */

	  saved_mmap_addr = (unsigned long) fakemap;
	  saved_mmap_length = sizeof (fakemap);
	  fakemap[0].Length = (saved_mem_lower << 10);
	  fakemap[1].Length = (memtmp << 10);
	  fakemap[2].Length = cont;
	}

      saved_mem_upper = memtmp;
    }

  printf("\r                        \r");	/* wipe out the messages */

  mbi.mem_upper = saved_mem_upper;
  mbi.mem_lower = saved_mem_lower;
  mbi.mmap_addr = saved_mmap_addr;
  mbi.mmap_length = saved_mmap_length;

#ifndef GRUB_UTIL
  is64bit = check_64bit ();
#endif

  /* Get the drive info.  */
  /* FIXME: This should be postponed until a Multiboot kernel actually
     requires it, because this could slow down the start-up
     unreasonably.  */
  mbi.drives_length = 0;
  mbi.drives_addr = addr;

  /* For now, GRUB doesn't probe floppies, since it is trivial to map
     floppy drives to BIOS drives.  */
#ifdef GRUB_UTIL
#define FIND_DRIVES 8
#else
#define FIND_DRIVES (*((char *)0x475))
#endif
  if (debug > 1)
	grub_printf ("hard drives: %d, int13: %X, int15: %X\n", FIND_DRIVES, *(unsigned long *)0x4C, *(unsigned long *)0x54);
  DEBUG_SLEEP

  for (drive = 0x80; drive < 0x80 + FIND_DRIVES; drive++)
    {
#undef FIND_DRIVES
      struct drive_info *info = (struct drive_info *) addr;
//      unsigned short *port;
      
      /* Get the geometry. This ensures that the drive is present.  */

      if (debug > 1)
	grub_printf ("get_diskinfo(%X), ", drive);

      if (get_diskinfo (drive, &tmp_geom))
	continue;//break;

      if (debug > 1)
	grub_printf (" %sC/H/S=%d/%d/%d, Sector Count/Size=%d/%d\n",
		(tmp_geom.flags & BIOSDISK_FLAG_LBA_EXTENSION) ? "LBA, " : "",
		tmp_geom.cylinders, tmp_geom.heads, tmp_geom.sectors,
		tmp_geom.total_sectors, tmp_geom.sector_size);
      
//      /* Clean out the I/O map.  */
//      grub_memset ((char *) io_map, 0, IO_MAP_SIZE * sizeof (unsigned short));

      /* Set the information.  */
      info->drive_number = drive;
      info->drive_mode = ((tmp_geom.flags & BIOSDISK_FLAG_LBA_EXTENSION)
			  ? MB_DI_LBA_MODE : MB_DI_CHS_MODE);
      info->drive_cylinders = tmp_geom.cylinders;
      info->drive_heads = tmp_geom.heads;
      info->drive_sectors = tmp_geom.sectors;

      addr += sizeof (struct drive_info);
//      for (port = io_map; *port; port++, addr += sizeof (unsigned short))
//	*((unsigned short *) addr) = *port;

      info->size = addr - (unsigned long) info;
      mbi.drives_length += info->size;
    }

  init_free_mem_start = addr;

  DEBUG_SLEEP

  /*
   *  Initialize other Multiboot Info flags.
   */

  mbi.flags = (MB_INFO_MEMORY | MB_INFO_CMDLINE | MB_INFO_BOOTDEV | MB_INFO_DRIVE_INFO | MB_INFO_CONFIG_TABLE | MB_INFO_BOOT_LOADER_NAME);
  if (saved_mmap_length)
    mbi.flags |= MB_INFO_MEM_MAP;
  
#endif /* STAGE1_5 */

#if !defined(STAGE1_5) && !defined(GRUB_UTIL)
  /* Set cdrom drive.  */
    
    /* Get the geometry.  */
    if (debug > 1)
	printf("boot drive=%X, ", boot_drive);
    cdrom_drive = get_cdinfo (boot_drive, &tmp_geom);
    if (! cdrom_drive || cdrom_drive != boot_drive)
	cdrom_drive = GRUB_INVALID_DRIVE;
    if (debug > 1)
	printf("%s\n", cdrom_drive == GRUB_INVALID_DRIVE ? "Not CD":"Is CD");
  DEBUG_SLEEP
#endif
  
#if !defined(STAGE1_5) && !defined(GRUB_UTIL)

  if (cdrom_drive == GRUB_INVALID_DRIVE)  
  {
    int err;
    int version;
    struct drive_parameters *drp = (struct drive_parameters *)0x600;

#ifdef GRUB_UTIL
#define FIND_DRIVES 8
#else
#define FIND_DRIVES (*((char *)0x475))
#endif
    for (drive = 0xFF; drive >= 0x7F; drive--)
    {
      if (drive >= 0x80 && drive < 0x80 + FIND_DRIVES)
	continue;
      
      /* Get the geometry.  */
      if (debug > 1)
	grub_printf ("\rget_cdinfo(%X),", drive);
      cdrom_drive = get_cdinfo (drive, &tmp_geom);
      if (cdrom_drive)
      {
	if (drive != 0x7F)
	  break;
	drive = cdrom_drive;
	cdrom_drive = get_cdinfo (drive, &tmp_geom);
	if (cdrom_drive == drive)
	  break;
	drive = 0x7F;
      }
    
      cdrom_drive = GRUB_INVALID_DRIVE;
    
      /* Some buggy BIOSes will hang at EBIOS `Get Drive Parameters' call
       * (INT 13h function 48h). So we only do further checks for Bochs.
       */
      
      if (bios_id != 1)		/* if it is not Bochs ... */
	continue;		/* ... skip and try next drive. */
      
      /* When qemu has a cdrom attached but not booted from cdrom, its
       * `get bootable cdrom status call', the int13/ax=4B01, returns CF=0
       * but with a wrong `Bootable CD-ROM Specification Packet' as follows:
       *
       * The first byte(packet size) is 0x13, all the rest bytes are 0's.
       * 
       * So we need to call get_diskinfo() here as a workaround.
       *
       *		(The bug was reported by Jacopo Lazzari. Thanks!)
       */

      if (drive >= 0x80)
      {
	version = check_int13_extensions (drive);

	if (! (version & 1)) /* not support functions 42h-44h, 47h-48h */
	    continue;	/* failure, try next drive. */
	
        /* It is safe to clear out DRP.  */
        grub_memset (drp, 0, sizeof (struct drive_parameters));
	  
	drp->size = sizeof (struct drive_parameters) - 16;
	  
	err = biosdisk_int13_extensions (0x4800, drive, drp);
	if (! err && drp->bytes_per_sector == ISO_SECTOR_SIZE)
	{
	    /* Assume it is CDROM.  */
	    cdrom_drive = drive;
	    break;
	}
      } /* if (drive >= 0x80) */
    
    } /* for (drive = 0x7F; drive < 0xff; drive++) */
  } /* if (cdrom_drive == GRUB_INVALID_DRIVE) */
#undef FIND_DRIVES
  
  if (debug > 1)
    grub_printf(" cdrom_drive == %X.\n", cdrom_drive);
  DEBUG_SLEEP
#endif /* ! STAGE1_5 && ! GRUB_UTIL */

  /* check if the no-emulation-mode bootable cdrom exists. */
  
  /* if cdrom_drive is active, we assume it is the boot device */
  if (saved_entryno == 0 && force_cdrom_as_boot_device)
	force_cdrom_as_boot_device = 0;
  if (cdrom_drive != GRUB_INVALID_DRIVE && force_cdrom_as_boot_device)
  {
    boot_drive = cdrom_drive;	/* force it to be the boot drive */
  }

  if (boot_drive == cdrom_drive)
	/* force it to be "whole drive" without partition table */
	install_partition = 0xFFFFFF;
  
  /* Set boot drive and partition.  */
  saved_drive = boot_drive;
  saved_partition = install_partition;

#ifndef GRUB_UTIL
#ifndef STAGE1_5
  debug = 1;
  min_cdrom_id = (cdrom_drive < 0xE0 && cdrom_drive >= 0xC0) ? 0xE0 : 0xC0;
  
  /* if grub.exe is booted as a Linux kernel, check the initrd disk. */

  /* the real mode zero page(only the beginning 2 sectors, the boot params) is loaded at 0xA00 */

  /* check the header signature "HdrS" (0x53726448) */

  ram_drive = 0x7f;	/* the default ram_drive is a floppy. */
  if (*(unsigned long*)(int*)(0xA00 + 0x202) == 0x53726448)
  {
	unsigned long initrd_addr;
	unsigned long initrd_size;
	
	initrd_addr = *(unsigned long*)(int*)(0xA00 + 0x218);
	initrd_size = *(unsigned long*)(int*)(0xA00 + 0x21c);
	if (initrd_addr && initrd_size)
	{
	    rd_base = initrd_addr;
	    rd_size = initrd_size;

	    /* check if there is a partition table */
	    if (*(unsigned short *)(initrd_addr + 0x40) == 0xAA55)
	    {
		if (! probe_mbr ((struct master_and_dos_boot_sector *)initrd_addr, 0, initrd_size, 0))
		    ram_drive = 0xfe;	/* partition table is valid, so let it be a harddrive */
		else
		    grub_printf ("\nUnrecognized partition table for RAM DRIVE; assuming floppy. Please rebuild\nit using a Microsoft-compatible FDISK tool, if the INITRD is a hard-disk image.\n");
	    }
	}
  }
#endif /* ! STAGE1_5 */
#endif /* ! GRUB_UTIL */

  /* Start main routine here.  */
  
  grub_printf("Starting cmain() ... ");
  
#if !defined(STAGE1_5) && !defined(GRUB_UTIL)
  DEBUG_SLEEP
#endif /* ! STAGE1_5 && ! GRUB_UTIL */
//  cmain ();	/* moved into asm.S and asmstub.c */
}