xref: /openbmc/u-boot/env/env.c (revision 861b85c4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Google, Inc
4  * Written by Simon Glass <sjg@chromium.org>
5  */
6 
7 #include <common.h>
8 #include <environment.h>
9 
10 DECLARE_GLOBAL_DATA_PTR;
11 
12 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
13 void env_fix_drivers(void)
14 {
15 	struct env_driver *drv;
16 	const int n_ents = ll_entry_count(struct env_driver, env_driver);
17 	struct env_driver *entry;
18 
19 	drv = ll_entry_start(struct env_driver, env_driver);
20 	for (entry = drv; entry != drv + n_ents; entry++) {
21 		if (entry->name)
22 			entry->name += gd->reloc_off;
23 		if (entry->load)
24 			entry->load += gd->reloc_off;
25 		if (entry->save)
26 			entry->save += gd->reloc_off;
27 		if (entry->init)
28 			entry->init += gd->reloc_off;
29 	}
30 }
31 #endif
32 
33 static struct env_driver *_env_driver_lookup(enum env_location loc)
34 {
35 	struct env_driver *drv;
36 	const int n_ents = ll_entry_count(struct env_driver, env_driver);
37 	struct env_driver *entry;
38 
39 	drv = ll_entry_start(struct env_driver, env_driver);
40 	for (entry = drv; entry != drv + n_ents; entry++) {
41 		if (loc == entry->location)
42 			return entry;
43 	}
44 
45 	/* Not found */
46 	return NULL;
47 }
48 
49 static enum env_location env_locations[] = {
50 #ifdef CONFIG_ENV_IS_IN_EEPROM
51 	ENVL_EEPROM,
52 #endif
53 #ifdef CONFIG_ENV_IS_IN_EXT4
54 	ENVL_EXT4,
55 #endif
56 #ifdef CONFIG_ENV_IS_IN_FAT
57 	ENVL_FAT,
58 #endif
59 #ifdef CONFIG_ENV_IS_IN_FLASH
60 	ENVL_FLASH,
61 #endif
62 #ifdef CONFIG_ENV_IS_IN_MMC
63 	ENVL_MMC,
64 #endif
65 #ifdef CONFIG_ENV_IS_IN_NAND
66 	ENVL_NAND,
67 #endif
68 #ifdef CONFIG_ENV_IS_IN_NVRAM
69 	ENVL_NVRAM,
70 #endif
71 #ifdef CONFIG_ENV_IS_IN_REMOTE
72 	ENVL_REMOTE,
73 #endif
74 #ifdef CONFIG_ENV_IS_IN_SPI_FLASH
75 	ENVL_SPI_FLASH,
76 #endif
77 #ifdef CONFIG_ENV_IS_IN_UBI
78 	ENVL_UBI,
79 #endif
80 #ifdef CONFIG_ENV_IS_NOWHERE
81 	ENVL_NOWHERE,
82 #endif
83 };
84 
85 static bool env_has_inited(enum env_location location)
86 {
87 	return gd->env_has_init & BIT(location);
88 }
89 
90 static void env_set_inited(enum env_location location)
91 {
92 	/*
93 	 * We're using a 32-bits bitmask stored in gd (env_has_init)
94 	 * using the above enum value as the bit index. We need to
95 	 * make sure that we're not overflowing it.
96 	 */
97 	BUILD_BUG_ON(ARRAY_SIZE(env_locations) > BITS_PER_LONG);
98 
99 	gd->env_has_init |= BIT(location);
100 }
101 
102 /**
103  * env_get_location() - Returns the best env location for a board
104  * @op: operations performed on the environment
105  * @prio: priority between the multiple environments, 0 being the
106  *        highest priority
107  *
108  * This will return the preferred environment for the given priority.
109  * This is overridable by boards if they need to.
110  *
111  * All implementations are free to use the operation, the priority and
112  * any other data relevant to their choice, but must take into account
113  * the fact that the lowest prority (0) is the most important location
114  * in the system. The following locations should be returned by order
115  * of descending priorities, from the highest to the lowest priority.
116  *
117  * Returns:
118  * an enum env_location value on success, a negative error code otherwise
119  */
120 __weak enum env_location env_get_location(enum env_operation op, int prio)
121 {
122 	if (prio >= ARRAY_SIZE(env_locations))
123 		return ENVL_UNKNOWN;
124 
125 	gd->env_load_prio = prio;
126 
127 	return env_locations[prio];
128 }
129 
130 
131 /**
132  * env_driver_lookup() - Finds the most suited environment location
133  * @op: operations performed on the environment
134  * @prio: priority between the multiple environments, 0 being the
135  *        highest priority
136  *
137  * This will try to find the available environment with the highest
138  * priority in the system.
139  *
140  * Returns:
141  * NULL on error, a pointer to a struct env_driver otherwise
142  */
143 static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
144 {
145 	enum env_location loc = env_get_location(op, prio);
146 	struct env_driver *drv;
147 
148 	if (loc == ENVL_UNKNOWN)
149 		return NULL;
150 
151 	drv = _env_driver_lookup(loc);
152 	if (!drv) {
153 		debug("%s: No environment driver for location %d\n", __func__,
154 		      loc);
155 		return NULL;
156 	}
157 
158 	return drv;
159 }
160 
161 __weak int env_get_char_spec(int index)
162 {
163 	return *(uchar *)(gd->env_addr + index);
164 }
165 
166 int env_get_char(int index)
167 {
168 	if (gd->env_valid == ENV_INVALID)
169 		return default_environment[index];
170 	else
171 		return env_get_char_spec(index);
172 }
173 
174 int env_load(void)
175 {
176 	struct env_driver *drv;
177 	int prio;
178 
179 	for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
180 		int ret;
181 
182 		if (!drv->load)
183 			continue;
184 
185 		if (!env_has_inited(drv->location))
186 			continue;
187 
188 		printf("Loading Environment from %s... ", drv->name);
189 		/*
190 		 * In error case, the error message must be printed during
191 		 * drv->load() in some underlying API, and it must be exactly
192 		 * one message.
193 		 */
194 		ret = drv->load();
195 		if (ret) {
196 			debug("Failed (%d)\n", ret);
197 		} else {
198 			printf("OK\n");
199 			return 0;
200 		}
201 	}
202 
203 	/*
204 	 * In case of invalid environment, we set the 'default' env location
205 	 * to the highest priority. In this way, next calls to env_save()
206 	 * will restore the environment at the right place.
207 	 */
208 	env_get_location(ENVOP_LOAD, 0);
209 
210 	return -ENODEV;
211 }
212 
213 int env_save(void)
214 {
215 	struct env_driver *drv;
216 
217 	drv = env_driver_lookup(ENVOP_SAVE, gd->env_load_prio);
218 	if (drv) {
219 		int ret;
220 
221 		if (!drv->save)
222 			return -ENODEV;
223 
224 		if (!env_has_inited(drv->location))
225 			return -ENODEV;
226 
227 		printf("Saving Environment to %s... ", drv->name);
228 		ret = drv->save();
229 		if (ret)
230 			printf("Failed (%d)\n", ret);
231 		else
232 			printf("OK\n");
233 
234 		if (!ret)
235 			return 0;
236 	}
237 
238 	return -ENODEV;
239 }
240 
241 int env_init(void)
242 {
243 	struct env_driver *drv;
244 	int ret = -ENOENT;
245 	int prio;
246 
247 	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
248 		if (!drv->init || !(ret = drv->init()))
249 			env_set_inited(drv->location);
250 
251 		debug("%s: Environment %s init done (ret=%d)\n", __func__,
252 		      drv->name, ret);
253 	}
254 
255 	if (!prio)
256 		return -ENODEV;
257 
258 	if (ret == -ENOENT) {
259 		gd->env_addr = (ulong)&default_environment[0];
260 		gd->env_valid = ENV_VALID;
261 
262 		return 0;
263 	}
264 
265 	return ret;
266 }
267