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authorJoe Hershberger <joe.hershberger@ni.com>2012-12-11 22:16:24 -0600
committerTom Rini <trini@ti.com>2012-12-13 11:46:55 -0700
commit170ab11075d3be56e89d6444abf1148329130f4b (patch)
treed3088ad532f4f4a0082f625ce50cfd120d6a6a1d /include/env_callback.h
parentbe11235ab802844e12d84921a38fd8ae4ddda080 (diff)
env: Add support for callbacks to environment vars
Add support for per-variable callbacks to the "hashtable" functions. Signed-off-by: Joe Hershberger <joe.hershberger@ni.com> !!!fix comment in callback
Diffstat (limited to 'include/env_callback.h')
-rw-r--r--include/env_callback.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/include/env_callback.h b/include/env_callback.h
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+++ b/include/env_callback.h
@@ -0,0 +1,62 @@
+/*
+ * (C) Copyright 2012
+ * Joe Hershberger, National Instruments, joe.hershberger@ni.com
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#ifndef __ENV_CALLBACK_H__
+#define __ENV_CALLBACK_H__
+
+#include <linker_lists.h>
+#include <search.h>
+
+#define ENV_CALLBACK_VAR ".callbacks"
+
+/* Board configs can define additional static callback bindings */
+#ifndef CONFIG_ENV_CALLBACK_LIST_STATIC
+#define CONFIG_ENV_CALLBACK_LIST_STATIC
+#endif
+
+/*
+ * This list of callback bindings is static, but may be overridden by defining
+ * a new association in the ".callbacks" environment variable.
+ */
+#define ENV_CALLBACK_LIST_STATIC ENV_CALLBACK_VAR ":callbacks," \
+ CONFIG_ENV_CALLBACK_LIST_STATIC
+
+struct env_clbk_tbl {
+ const char *name; /* Callback name */
+ int (*callback)(const char *name, const char *value, enum env_op op,
+ int flags);
+};
+
+struct env_clbk_tbl *find_env_callback(const char *);
+void env_callback_init(ENTRY *var_entry);
+
+/*
+ * Define a callback that can be associated with variables.
+ * when associated through the ".callbacks" environment variable, the callback
+ * will be executed any time the variable is inserted, overwritten, or deleted.
+ */
+#define U_BOOT_ENV_CALLBACK(name, callback) \
+ ll_entry_declare(struct env_clbk_tbl, name, env_clbk, env_clbk) = \
+ {#name, callback}
+
+#endif /* __ENV_CALLBACK_H__ */