stage2.c

i386的bootloader源码grub

			first_entry++;
		      
		      c = 'O';
		    }

		  cur_entry = get_entry (menu_entries,
					 first_entry + entryno,
					 0);

		  if (c == 'O')
		    {
		      grub_memmove (cur_entry + 2, cur_entry,
				    ((int) heap) - ((int) cur_entry));

		      cur_entry[0] = ' ';
		      cur_entry[1] = 0;

		      heap += 2;

		      num_entries++;
		    }
		  else if (num_entries > 0)
		    {
		      char *ptr = get_entry(menu_entries,
					    first_entry + entryno + 1,
					    0);

		      grub_memmove (cur_entry, ptr,
				    ((int) heap) - ((int) ptr));
		      heap -= (((int) ptr) - ((int) cur_entry));

		      num_entries--;

		      if (entryno >= num_entries)
			entryno--;
		      if (first_entry && num_entries < 12 + first_entry)
			first_entry--;
		    }

		  if (current_term->flags & TERM_DUMB)
		    {
		      grub_printf ("\n\n");
		      print_entries_raw (num_entries, first_entry,
					 menu_entries);
		      grub_printf ("\n");
		    }
		  else
		    print_entries (3, 12, first_entry, entryno, menu_entries);
		}

	      cur_entry = menu_entries;
	      if (c == 27)
		return;
	      if (c == 'b')
		break;
	    }

	  if (! auth && password)
	    {
	      if (c == 'p')
		{
		  /* Do password check here! */
		  char entered[32];
		  char *pptr = password;

		  if (current_term->flags & TERM_DUMB)
		    grub_printf ("\r                                    ");
		  else
		    gotoxy (1, 21);

		  /* Wipe out the previously entered password */
		  grub_memset (entered, 0, sizeof (entered));
		  get_cmdline (" Password: ", entered, 31, '*', 0);

		  while (! isspace (*pptr) && *pptr)
		    pptr++;

		  /* Make sure that PASSWORD is NUL-terminated.  */
		  *pptr++ = 0;

		  if (! check_password (entered, password, password_type))
		    {
		      char *new_file = config_file;
		      while (isspace (*pptr))
			pptr++;

		      /* If *PPTR is NUL, then allow the user to use
			 privileged instructions, otherwise, load
			 another configuration file.  */
		      if (*pptr != 0)
			{
			  while ((*(new_file++) = *(pptr++)) != 0)
			    ;

			  /* Make sure that the user will not have
			     authority in the next configuration.  */
			  auth = 0;
			  return;
			}
		      else
			{
			  /* Now the user is superhuman.  */
			  auth = 1;
			  goto restart;
			}
		    }
		  else
		    {
		      grub_printf ("Failed!\n      Press any key to continue...");
		      getkey ();
		      goto restart;
		    }
		}
	    }
	  else
	    {
	      if (c == 'e')
		{
		  int new_num_entries = 0, i = 0;
		  char *new_heap;

		  if (config_entries)
		    {
		      new_heap = heap;
		      cur_entry = get_entry (config_entries,
					     first_entry + entryno,
					     1);
		    }
		  else
		    {
		      /* safe area! */
		      new_heap = heap + NEW_HEAPSIZE + 1;
		      cur_entry = get_entry (menu_entries,
					     first_entry + entryno,
					     0);
		    }

		  do
		    {
		      while ((*(new_heap++) = cur_entry[i++]) != 0);
		      new_num_entries++;
		    }
		  while (config_entries && cur_entry[i]);

		  /* this only needs to be done if config_entries is non-NULL,
		     but it doesn't hurt to do it always */
		  *(new_heap++) = 0;

		  if (config_entries)
		    run_menu (heap, NULL, new_num_entries, new_heap, 0);
		  else
		    {
		      cls ();
		      print_cmdline_message (0);

		      new_heap = heap + NEW_HEAPSIZE + 1;

		      saved_drive = boot_drive;
		      saved_partition = install_partition;
		      current_drive = GRUB_INVALID_DRIVE;

		      if (! get_cmdline (PACKAGE " edit> ", new_heap,
					 NEW_HEAPSIZE + 1, 0, 1))
			{
			  int j = 0;

			  /* get length of new command */
			  while (new_heap[j++])
			    ;

			  if (j < 2)
			    {
			      j = 2;
			      new_heap[0] = ' ';
			      new_heap[1] = 0;
			    }

			  /* align rest of commands properly */
			  grub_memmove (cur_entry + j, cur_entry + i,
					(int) heap - ((int) cur_entry + i));

			  /* copy command to correct area */
			  grub_memmove (cur_entry, new_heap, j);

			  heap += (j - i);
			}
		    }

		  goto restart;
		}
	      if (c == 'c')
		{
		  enter_cmdline (heap, 0);
		  goto restart;
		}
#ifdef GRUB_UTIL
	      if (c == 'q')
		{
		  /* The same as ``quit''.  */
		  stop ();
		}
#endif
	    }
	}
    }
  
  /* Attempt to boot an entry.  */
  
 boot_entry:
  
  cls ();
  setcursor (1);
  
  while (1)
    {
      if (config_entries)
	printf ("  Booting \'%s\'\n\n",
		get_entry (menu_entries, first_entry + entryno, 0));
      else
	printf ("  Booting command-list\n\n");

      if (! cur_entry)
	cur_entry = get_entry (config_entries, first_entry + entryno, 1);

      /* Set CURRENT_ENTRYNO for the command "savedefault".  */
      current_entryno = first_entry + entryno;
      
      if (run_script (cur_entry, heap))
	{
	  if (fallback_entry < 0)
	    break;
	  else
	    {
	      cur_entry = NULL;
	      first_entry = 0;
	      entryno = fallback_entry;
	      fallback_entry = -1;
	    }
	}
      else
	break;
    }

  show_menu = 1;
  goto restart;
}


static int
get_line_from_config (char *cmdline, int maxlen, int read_from_file)
{
  int pos = 0, literal = 0, comment = 0;
  char c;  /* since we're loading it a byte at a time! */
  
  while (1)
    {
      if (read_from_file)
	{
	  if (! grub_read (&c, 1))
	    break;
	}
      else
	{
	  if (! read_from_preset_menu (&c, 1))
	    break;
	}

      /* Skip all carriage returns.  */
      if (c == '\r')
	continue;

      /* Replace tabs with spaces.  */
      if (c == '\t')
	c = ' ';

      /* The previous is a backslash, then...  */
      if (literal)
	{
	  /* If it is a newline, replace it with a space and continue.  */
	  if (c == '\n')
	    {
	      c = ' ';
	      
	      /* Go back to overwrite a backslash.  */
	      if (pos > 0)
		pos--;
	    }
	    
	  literal = 0;
	}
	  
      /* translate characters first! */
      if (c == '\\' && ! literal)
	literal = 1;

      if (comment)
	{
	  if (c == '\n')
	    comment = 0;
	}
      else if (! pos)
	{
	  if (c == '#')
	    comment = 1;
	  else if ((c != ' ') && (c != '\n'))
	    cmdline[pos++] = c;
	}
      else
	{
	  if (c == '\n')
	    break;

	  if (pos < maxlen)
	    cmdline[pos++] = c;
	}
    }

  cmdline[pos] = 0;

  return pos;
}


/* This is the starting function in C.  */
void
cmain (void)
{
  int config_len, menu_len, num_entries;
  char *config_entries, *menu_entries;
  char *kill_buf = (char *) KILL_BUF;

  auto void reset (void);
  void reset (void)
    {
      count_lines = -1;
      config_len = 0;
      menu_len = 0;
      num_entries = 0;
      config_entries = (char *) mbi.drives_addr + mbi.drives_length;
      menu_entries = (char *) MENU_BUF;
      init_config ();
    }
      
  /* Initialize the environment for restarting Stage 2.  */
  grub_setjmp (restart_env);
  
  /* Initialize the kill buffer.  */
  *kill_buf = 0;

  /* Never return.  */
  for (;;)
    {
      int is_opened, is_preset;

      reset ();
      
      /* Here load the configuration file.  */
      
#ifdef GRUB_UTIL
      if (use_config_file)
#endif /* GRUB_UTIL */
	{
	  do
	    {
	      /* STATE 0:  Before any title command.
		 STATE 1:  In a title command.
		 STATE >1: In a entry after a title command.  */
	      int state = 0, prev_config_len = 0, prev_menu_len = 0;
	      char *cmdline;

	      /* Try the preset menu first. This will succeed at most once,
		 because close_preset_menu disables the preset menu.  */
	      is_opened = is_preset = open_preset_menu ();
	      if (! is_opened)
		{
		  is_opened = grub_open (config_file);
		  errnum = ERR_NONE;
		}

	      if (! is_opened)
		break;

	      /* This is necessary, because the menu must be overrided.  */
	      reset ();
	      
	      cmdline = (char *) CMDLINE_BUF;
	      while (get_line_from_config (cmdline, NEW_HEAPSIZE,
					   ! is_preset))
		{
		  struct builtin *builtin;
		  
		  /* Get the pointer to the builtin structure.  */
		  builtin = find_command (cmdline);
		  errnum = 0;
		  if (! builtin)
		    /* Unknown command. Just skip now.  */
		    continue;
		  
		  if (builtin->flags & BUILTIN_TITLE)
		    {
		      char *ptr;
		      
		      /* the command "title" is specially treated.  */
		      if (state > 1)
			{
			  /* The next title is found.  */
			  num_entries++;
			  config_entries[config_len++] = 0;
			  prev_menu_len = menu_len;
			  prev_config_len = config_len;
			}
		      else
			{
			  /* The first title is found.  */
			  menu_len = prev_menu_len;
			  config_len = prev_config_len;
			}
		      
		      /* Reset the state.  */
		      state = 1;
		      
		      /* Copy title into menu area.  */
		      ptr = skip_to (1, cmdline);
		      while ((menu_entries[menu_len++] = *(ptr++)) != 0)
			;
		    }
		  else if (! state)
		    {
		      /* Run a command found is possible.  */
		      if (builtin->flags & BUILTIN_MENU)
			{
			  char *arg = skip_to (1, cmdline);
			  (builtin->func) (arg, BUILTIN_MENU);
			  errnum = 0;
			}
		      else
			/* Ignored.  */
			continue;
		    }
		  else
		    {
		      char *ptr = cmdline;
		      
		      state++;
		      /* Copy config file data to config area.  */
		      while ((config_entries[config_len++] = *ptr++) != 0)
			;
		    }
		}
	      
	      if (state > 1)
		{
		  /* Finish the last entry.  */
		  num_entries++;
		  config_entries[config_len++] = 0;
		}
	      else
		{
		  menu_len = prev_menu_len;
		  config_len = prev_config_len;
		}
	      
	      menu_entries[menu_len++] = 0;
	      config_entries[config_len++] = 0;
	      grub_memmove (config_entries + config_len, menu_entries,
			    menu_len);
	      menu_entries = config_entries + config_len;
	      
	      /* Check if the default entry is present. Otherwise reset
		 it to fallback if fallback is valid, or to DEFAULT_ENTRY 
		 if not.  */
	      if (default_entry >= num_entries)
		{
		  if (fallback_entry < 0 || fallback_entry >= num_entries)
		    default_entry = 0;
		  else
		    default_entry = fallback_entry;
		}
	      
	      if (is_preset)
		close_preset_menu ();
	      else
		grub_close ();
	    }
	  while (is_preset);
	}

      if (! num_entries)
	{
	  /* If no acceptable config file, goto command-line, starting
	     heap from where the config entries would have been stored
	     if there were any.  */
	  enter_cmdline (config_entries, 1);
	}
      else
	{
	  /* Run menu interface.  */
	  run_menu (menu_entries, config_entries, num_entries,
		    menu_entries + menu_len, default_entry);
	}
    }
}