/* * (C) Copyright 2012 * Joe Hershberger, National Instruments, joe.hershberger@ni.com * * SPDX-License-Identifier: GPL-2.0+ */ #include <common.h> #include <environment.h> #if defined(CONFIG_NEEDS_MANUAL_RELOC) DECLARE_GLOBAL_DATA_PTR; #endif /* * Look up a callback function pointer by name */ static struct env_clbk_tbl *find_env_callback(const char *name) { struct env_clbk_tbl *clbkp; int i; int num_callbacks = ll_entry_count(struct env_clbk_tbl, env_clbk); if (name == NULL) return NULL; /* look up the callback in the linker-list */ for (i = 0, clbkp = ll_entry_start(struct env_clbk_tbl, env_clbk); i < num_callbacks; i++, clbkp++) { if (strcmp(name, clbkp->name) == 0) return clbkp; } return NULL; } static int first_call = 1; static const char *callback_list; /* * Look for a possible callback for a newly added variable * This is called specifically when the variable did not exist in the hash * previously, so the blanket update did not find this variable. */ void env_callback_init(ENTRY *var_entry) { const char *var_name = var_entry->key; char callback_name[256] = ""; struct env_clbk_tbl *clbkp; int ret = 1; if (first_call) { callback_list = getenv(ENV_CALLBACK_VAR); first_call = 0; } /* look in the ".callbacks" var for a reference to this variable */ if (callback_list != NULL) ret = env_attr_lookup(callback_list, var_name, callback_name); /* only if not found there, look in the static list */ if (ret) ret = env_attr_lookup(ENV_CALLBACK_LIST_STATIC, var_name, callback_name); /* if an association was found, set the callback pointer */ if (!ret && strlen(callback_name)) { clbkp = find_env_callback(callback_name); if (clbkp != NULL) #if defined(CONFIG_NEEDS_MANUAL_RELOC) var_entry->callback = clbkp->callback + gd->reloc_off; #else var_entry->callback = clbkp->callback; #endif } } /* * Called on each existing env var prior to the blanket update since removing * a callback association should remove its callback. */ static int clear_callback(ENTRY *entry) { entry->callback = NULL; return 0; } /* * Call for each element in the list that associates variables to callbacks */ static int set_callback(const char *name, const char *value) { ENTRY e, *ep; struct env_clbk_tbl *clbkp; e.key = name; e.data = NULL; hsearch_r(e, FIND, &ep, &env_htab, 0); /* does the env variable actually exist? */ if (ep != NULL) { /* the assocaition delares no callback, so remove the pointer */ if (value == NULL || strlen(value) == 0) ep->callback = NULL; else { /* assign the requested callback */ clbkp = find_env_callback(value); if (clbkp != NULL) #if defined(CONFIG_NEEDS_MANUAL_RELOC) ep->callback = clbkp->callback + gd->reloc_off; #else ep->callback = clbkp->callback; #endif } } return 0; } static int on_callbacks(const char *name, const char *value, enum env_op op, int flags) { /* remove all callbacks */ hwalk_r(&env_htab, clear_callback); /* configure any static callback bindings */ env_attr_walk(ENV_CALLBACK_LIST_STATIC, set_callback); /* configure any dynamic callback bindings */ env_attr_walk(value, set_callback); return 0; } U_BOOT_ENV_CALLBACK(callbacks, on_callbacks);