include/env_callback.h

   1 /*
   2  * (C) Copyright 2012
   3  * Joe Hershberger, National Instruments, joe.hershberger@ni.com
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  */
  23
  24 #ifndef __ENV_CALLBACK_H__
  25 #define __ENV_CALLBACK_H__
  26
  27 #include <linker_lists.h>
  28 #include <search.h>
  29
  30 #define ENV_CALLBACK_VAR ".callbacks"
  31
  32 /* Board configs can define additional static callback bindings */
  33 #ifndef CONFIG_ENV_CALLBACK_LIST_STATIC
  34 #define CONFIG_ENV_CALLBACK_LIST_STATIC
  35 #endif
  36
  37 /*
  38  * This list of callback bindings is static, but may be overridden by defining
  39  * a new association in the ".callbacks" environment variable.
  40  */
  41 #define ENV_CALLBACK_LIST_STATIC ENV_CALLBACK_VAR ":callbacks," \
  42         CONFIG_ENV_CALLBACK_LIST_STATIC
  43
  44 struct env_clbk_tbl {
  45         const char *name;               /* Callback name */
  46         int (*callback)(const char *name, const char *value, enum env_op op,
  47                 int flags);
  48 };
  49
  50 struct env_clbk_tbl *find_env_callback(const char *);
  51 void env_callback_init(ENTRY *var_entry);
  52
  53 /*
  54  * Define a callback that can be associated with variables.
  55  * when associated through the ".callbacks" environment variable, the callback
  56  * will be executed any time the variable is inserted, overwritten, or deleted.
  57  */
  58 #define U_BOOT_ENV_CALLBACK(name, callback) \
  59         ll_entry_declare(struct env_clbk_tbl, name, env_clbk, env_clbk) = \
  60         {#name, callback}
  61
  62 #endif /* __ENV_CALLBACK_H__ */