xref: /openbmc/u-boot/env/env.c (revision 5512f5cc)
1 /*
2  * Copyright (C) 2017 Google, Inc
3  * Written by Simon Glass <sjg@chromium.org>
4  *
5  * SPDX-License-Identifier:     GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <environment.h>
10 
11 DECLARE_GLOBAL_DATA_PTR;
12 
13 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
14 void env_fix_drivers(void)
15 {
16 	struct env_driver *drv;
17 	const int n_ents = ll_entry_count(struct env_driver, env_driver);
18 	struct env_driver *entry;
19 
20 	drv = ll_entry_start(struct env_driver, env_driver);
21 	for (entry = drv; entry != drv + n_ents; entry++) {
22 		if (entry->name)
23 			entry->name += gd->reloc_off;
24 		if (entry->load)
25 			entry->load += gd->reloc_off;
26 		if (entry->save)
27 			entry->save += gd->reloc_off;
28 		if (entry->init)
29 			entry->init += gd->reloc_off;
30 	}
31 }
32 #endif
33 
34 static struct env_driver *_env_driver_lookup(enum env_location loc)
35 {
36 	struct env_driver *drv;
37 	const int n_ents = ll_entry_count(struct env_driver, env_driver);
38 	struct env_driver *entry;
39 
40 	drv = ll_entry_start(struct env_driver, env_driver);
41 	for (entry = drv; entry != drv + n_ents; entry++) {
42 		if (loc == entry->location)
43 			return entry;
44 	}
45 
46 	/* Not found */
47 	return NULL;
48 }
49 
50 static enum env_location env_locations[] = {
51 #ifdef CONFIG_ENV_IS_IN_EEPROM
52 	ENVL_EEPROM,
53 #endif
54 #ifdef CONFIG_ENV_IS_IN_EXT4
55 	ENVL_EXT4,
56 #endif
57 #ifdef CONFIG_ENV_IS_IN_FAT
58 	ENVL_FAT,
59 #endif
60 #ifdef CONFIG_ENV_IS_IN_FLASH
61 	ENVL_FLASH,
62 #endif
63 #ifdef CONFIG_ENV_IS_IN_MMC
64 	ENVL_MMC,
65 #endif
66 #ifdef CONFIG_ENV_IS_IN_NAND
67 	ENVL_NAND,
68 #endif
69 #ifdef CONFIG_ENV_IS_IN_NVRAM
70 	ENVL_NVRAM,
71 #endif
72 #ifdef CONFIG_ENV_IS_IN_REMOTE
73 	ENVL_REMOTE,
74 #endif
75 #ifdef CONFIG_ENV_IS_IN_SPI_FLASH
76 	ENVL_SPI_FLASH,
77 #endif
78 #ifdef CONFIG_ENV_IS_IN_UBI
79 	ENVL_UBI,
80 #endif
81 #ifdef CONFIG_ENV_IS_NOWHERE
82 	ENVL_NOWHERE,
83 #endif
84 };
85 
86 static bool env_has_inited(enum env_location location)
87 {
88 	return gd->env_has_init & BIT(location);
89 }
90 
91 static void env_set_inited(enum env_location location)
92 {
93 	/*
94 	 * We're using a 32-bits bitmask stored in gd (env_has_init)
95 	 * using the above enum value as the bit index. We need to
96 	 * make sure that we're not overflowing it.
97 	 */
98 	BUILD_BUG_ON(ARRAY_SIZE(env_locations) > BITS_PER_LONG);
99 
100 	gd->env_has_init |= BIT(location);
101 }
102 
103 /**
104  * env_get_location() - Returns the best env location for a board
105  * @op: operations performed on the environment
106  * @prio: priority between the multiple environments, 0 being the
107  *        highest priority
108  *
109  * This will return the preferred environment for the given priority.
110  * This is overridable by boards if they need to.
111  *
112  * All implementations are free to use the operation, the priority and
113  * any other data relevant to their choice, but must take into account
114  * the fact that the lowest prority (0) is the most important location
115  * in the system. The following locations should be returned by order
116  * of descending priorities, from the highest to the lowest priority.
117  *
118  * Returns:
119  * an enum env_location value on success, a negative error code otherwise
120  */
121 __weak enum env_location env_get_location(enum env_operation op, int prio)
122 {
123 	switch (op) {
124 	case ENVOP_GET_CHAR:
125 	case ENVOP_INIT:
126 	case ENVOP_LOAD:
127 		if (prio >= ARRAY_SIZE(env_locations))
128 			return ENVL_UNKNOWN;
129 
130 		gd->env_load_location = env_locations[prio];
131 		return gd->env_load_location;
132 
133 	case ENVOP_SAVE:
134 		return gd->env_load_location;
135 	}
136 
137 	return ENVL_UNKNOWN;
138 }
139 
140 
141 /**
142  * env_driver_lookup() - Finds the most suited environment location
143  * @op: operations performed on the environment
144  * @prio: priority between the multiple environments, 0 being the
145  *        highest priority
146  *
147  * This will try to find the available environment with the highest
148  * priority in the system.
149  *
150  * Returns:
151  * NULL on error, a pointer to a struct env_driver otherwise
152  */
153 static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
154 {
155 	enum env_location loc = env_get_location(op, prio);
156 	struct env_driver *drv;
157 
158 	if (loc == ENVL_UNKNOWN)
159 		return NULL;
160 
161 	drv = _env_driver_lookup(loc);
162 	if (!drv) {
163 		debug("%s: No environment driver for location %d\n", __func__,
164 		      loc);
165 		return NULL;
166 	}
167 
168 	return drv;
169 }
170 
171 __weak int env_get_char_spec(int index)
172 {
173 	return *(uchar *)(gd->env_addr + index);
174 }
175 
176 int env_get_char(int index)
177 {
178 	if (gd->env_valid == ENV_INVALID)
179 		return default_environment[index];
180 	else
181 		return env_get_char_spec(index);
182 }
183 
184 int env_load(void)
185 {
186 	struct env_driver *drv;
187 	int prio;
188 
189 	for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
190 		int ret;
191 
192 		if (!drv->load)
193 			continue;
194 
195 		if (!env_has_inited(drv->location))
196 			continue;
197 
198 		printf("Loading Environment from %s... ", drv->name);
199 		ret = drv->load();
200 		if (ret)
201 			printf("Failed (%d)\n", ret);
202 		else
203 			printf("OK\n");
204 
205 		if (!ret)
206 			return 0;
207 	}
208 
209 	return -ENODEV;
210 }
211 
212 int env_save(void)
213 {
214 	struct env_driver *drv;
215 	int prio;
216 
217 	for (prio = 0; (drv = env_driver_lookup(ENVOP_SAVE, prio)); prio++) {
218 		int ret;
219 
220 		if (!drv->save)
221 			continue;
222 
223 		if (!env_has_inited(drv->location))
224 			continue;
225 
226 		printf("Saving Environment to %s... ", drv->name);
227 		ret = drv->save();
228 		if (ret)
229 			printf("Failed (%d)\n", ret);
230 		else
231 			printf("OK\n");
232 
233 		if (!ret)
234 			return 0;
235 	}
236 
237 	return -ENODEV;
238 }
239 
240 int env_init(void)
241 {
242 	struct env_driver *drv;
243 	int ret = -ENOENT;
244 	int prio;
245 
246 	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
247 		if (!drv->init || !(ret = drv->init()))
248 			env_set_inited(drv->location);
249 
250 		debug("%s: Environment %s init done (ret=%d)\n", __func__,
251 		      drv->name, ret);
252 	}
253 
254 	if (!prio)
255 		return -ENODEV;
256 
257 	if (ret == -ENOENT) {
258 		gd->env_addr = (ulong)&default_environment[0];
259 		gd->env_valid = ENV_VALID;
260 
261 		return 0;
262 	}
263 
264 	return ret;
265 }
266