xref: /openbmc/u-boot/env/env.c (revision 8ee59472)
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 	switch (op) {
123 	case ENVOP_GET_CHAR:
124 	case ENVOP_INIT:
125 	case ENVOP_LOAD:
126 		if (prio >= ARRAY_SIZE(env_locations))
127 			return ENVL_UNKNOWN;
128 
129 		gd->env_load_location = env_locations[prio];
130 		return gd->env_load_location;
131 
132 	case ENVOP_SAVE:
133 		return gd->env_load_location;
134 	}
135 
136 	return ENVL_UNKNOWN;
137 }
138 
139 
140 /**
141  * env_driver_lookup() - Finds the most suited environment location
142  * @op: operations performed on the environment
143  * @prio: priority between the multiple environments, 0 being the
144  *        highest priority
145  *
146  * This will try to find the available environment with the highest
147  * priority in the system.
148  *
149  * Returns:
150  * NULL on error, a pointer to a struct env_driver otherwise
151  */
152 static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
153 {
154 	enum env_location loc = env_get_location(op, prio);
155 	struct env_driver *drv;
156 
157 	if (loc == ENVL_UNKNOWN)
158 		return NULL;
159 
160 	drv = _env_driver_lookup(loc);
161 	if (!drv) {
162 		debug("%s: No environment driver for location %d\n", __func__,
163 		      loc);
164 		return NULL;
165 	}
166 
167 	return drv;
168 }
169 
170 __weak int env_get_char_spec(int index)
171 {
172 	return *(uchar *)(gd->env_addr + index);
173 }
174 
175 int env_get_char(int index)
176 {
177 	if (gd->env_valid == ENV_INVALID)
178 		return default_environment[index];
179 	else
180 		return env_get_char_spec(index);
181 }
182 
183 int env_load(void)
184 {
185 	struct env_driver *drv;
186 	int prio;
187 
188 	for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
189 		int ret;
190 
191 		if (!drv->load)
192 			continue;
193 
194 		if (!env_has_inited(drv->location))
195 			continue;
196 
197 		printf("Loading Environment from %s... ", drv->name);
198 		ret = drv->load();
199 		if (ret)
200 			printf("Failed (%d)\n", ret);
201 		else
202 			printf("OK\n");
203 
204 		if (!ret)
205 			return 0;
206 	}
207 
208 	return -ENODEV;
209 }
210 
211 int env_save(void)
212 {
213 	struct env_driver *drv;
214 	int prio;
215 
216 	for (prio = 0; (drv = env_driver_lookup(ENVOP_SAVE, prio)); prio++) {
217 		int ret;
218 
219 		if (!drv->save)
220 			continue;
221 
222 		if (!env_has_inited(drv->location))
223 			continue;
224 
225 		printf("Saving Environment to %s... ", drv->name);
226 		ret = drv->save();
227 		if (ret)
228 			printf("Failed (%d)\n", ret);
229 		else
230 			printf("OK\n");
231 
232 		if (!ret)
233 			return 0;
234 	}
235 
236 	return -ENODEV;
237 }
238 
239 int env_init(void)
240 {
241 	struct env_driver *drv;
242 	int ret = -ENOENT;
243 	int prio;
244 
245 	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
246 		if (!drv->init || !(ret = drv->init()))
247 			env_set_inited(drv->location);
248 
249 		debug("%s: Environment %s init done (ret=%d)\n", __func__,
250 		      drv->name, ret);
251 	}
252 
253 	if (!prio)
254 		return -ENODEV;
255 
256 	if (ret == -ENOENT) {
257 		gd->env_addr = (ulong)&default_environment[0];
258 		gd->env_valid = ENV_VALID;
259 
260 		return 0;
261 	}
262 
263 	return ret;
264 }
265