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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | // SPDX-License-Identifier: GPL-2.0+ /* * (C) Copyright 2012 * Joe Hershberger, National Instruments, joe.hershberger@ni.com */ #include <env.h> #include <env_internal.h> #include <asm/global_data.h> /* * 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(struct env_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 = env_get(ENV_CALLBACK_VAR); first_call = 0; } var_entry->callback = NULL; /* 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) var_entry->callback = clbkp->callback; } } /* * Called on each existing env var prior to the blanket update since removing * a callback association should remove its callback. */ static int clear_callback(struct env_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, void *priv) { struct env_entry e, *ep; struct env_clbk_tbl *clbkp; e.key = name; e.data = NULL; e.callback = NULL; hsearch_r(e, ENV_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) ep->callback = clbkp->callback; } } 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, NULL); /* configure any dynamic callback bindings */ env_attr_walk(value, set_callback, NULL); return 0; } U_BOOT_ENV_CALLBACK(callbacks, on_callbacks); |