u-boot/env/callback.c
Simon Glass 3f0d680745 env: Drop the ACTION typedef
Avoid using a typedef here which is unnecessary. Add an 'env_' prefix to
both the enum and its members to make it clear that these are related to
the environment.

Add an ENV prefix to these two flags so that it is clear what they relate
to. Also move them to env.h since they are part of the public API. Use an
enum rather than a #define to tie them together.

Signed-off-by: Simon Glass <sjg@chromium.org>
2019-08-11 16:43:41 -04:00

136 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2012
* Joe Hershberger, National Instruments, joe.hershberger@ni.com
*/
#include <common.h>
#include <env.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(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;
}
/* 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(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)
#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, NULL);
/* configure any dynamic callback bindings */
env_attr_walk(value, set_callback, NULL);
return 0;
}
U_BOOT_ENV_CALLBACK(callbacks, on_callbacks);