kern/handler.c

   1 /* handler.c - grub handler function */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2009  Free Software Foundation, Inc.
   5  *
   6  *  GRUB 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 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/handler.h>
  21
  22 grub_handler_class_t grub_handler_class_list;
  23
  24 void
  25 grub_handler_register (grub_handler_class_t class, grub_handler_t handler)
  26 {
  27   int first_handler = (class->handler_list == 0);
  28
  29   grub_list_push (GRUB_AS_LIST_P (&class->handler_list),
  30                   GRUB_AS_LIST (handler));
  31
  32   if (first_handler)
  33     {
  34       grub_list_push (GRUB_AS_LIST_P (&grub_handler_class_list),
  35                       GRUB_AS_LIST (class));
  36       grub_handler_set_current (class, handler);
  37     }
  38 }
  39
  40 void
  41 grub_handler_unregister (grub_handler_class_t class, grub_handler_t handler)
  42 {
  43   grub_list_remove (GRUB_AS_LIST_P (&class->handler_list),
  44                     GRUB_AS_LIST (handler));
  45
  46   if (class->handler_list == 0)
  47     grub_list_remove (GRUB_AS_LIST_P (&grub_handler_class_list),
  48                       GRUB_AS_LIST (class));
  49 }
  50
  51 grub_err_t
  52 grub_handler_set_current (grub_handler_class_t class, grub_handler_t handler)
  53 {
  54   if (class->cur_handler && class->cur_handler->fini)
  55     if ((class->cur_handler->fini) () != GRUB_ERR_NONE)
  56       return grub_errno;
  57
  58   if (handler->init)
  59     if ((handler->init) () != GRUB_ERR_NONE)
  60       return grub_errno;
  61
  62   class->cur_handler = handler;
  63   return GRUB_ERR_NONE;
  64 }