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
127
128
129
130
131
132
133
134
135
136
|
// 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, 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);
|
