[u-boot.git] / env / env.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2017 Google, Inc
 * Written by Simon Glass <[email protected]>
 */

#include <common.h>
#include <env.h>
#include <env_internal.h>
#include <log.h>
#include <asm/global_data.h>
#include <linux/bitops.h>
#include <linux/bug.h>

DECLARE_GLOBAL_DATA_PTR;

#if defined(CONFIG_NEEDS_MANUAL_RELOC)
void env_fix_drivers(void)
{
	struct env_driver *drv;
	const int n_ents = ll_entry_count(struct env_driver, env_driver);
	struct env_driver *entry;

	drv = ll_entry_start(struct env_driver, env_driver);
	for (entry = drv; entry != drv + n_ents; entry++) {
		if (entry->name)
			entry->name += gd->reloc_off;
		if (entry->load)
			entry->load += gd->reloc_off;
		if (entry->save)
			entry->save += gd->reloc_off;
		if (entry->erase)
			entry->erase += gd->reloc_off;
		if (entry->init)
			entry->init += gd->reloc_off;
	}
}
#endif

static struct env_driver *_env_driver_lookup(enum env_location loc)
{
	struct env_driver *drv;
	const int n_ents = ll_entry_count(struct env_driver, env_driver);
	struct env_driver *entry;

	drv = ll_entry_start(struct env_driver, env_driver);
	for (entry = drv; entry != drv + n_ents; entry++) {
		if (loc == entry->location)
			return entry;
	}

	/* Not found */
	return NULL;
}

static enum env_location env_locations[] = {
#ifdef CONFIG_ENV_IS_IN_EEPROM
	ENVL_EEPROM,
#endif
#ifdef CONFIG_ENV_IS_IN_EXT4
	ENVL_EXT4,
#endif
#ifdef CONFIG_ENV_IS_IN_FAT
	ENVL_FAT,
#endif
#ifdef CONFIG_ENV_IS_IN_FLASH
	ENVL_FLASH,
#endif
#ifdef CONFIG_ENV_IS_IN_MMC
	ENVL_MMC,
#endif
#ifdef CONFIG_ENV_IS_IN_NAND
	ENVL_NAND,
#endif
#ifdef CONFIG_ENV_IS_IN_NVRAM
	ENVL_NVRAM,
#endif
#ifdef CONFIG_ENV_IS_IN_REMOTE
	ENVL_REMOTE,
#endif
#ifdef CONFIG_ENV_IS_IN_SPI_FLASH
	ENVL_SPI_FLASH,
#endif
#ifdef CONFIG_ENV_IS_IN_UBI
	ENVL_UBI,
#endif
#ifdef CONFIG_ENV_IS_NOWHERE
	ENVL_NOWHERE,
#endif
};

static bool env_has_inited(enum env_location location)
{
	return gd->env_has_init & BIT(location);
}

static void env_set_inited(enum env_location location)
{
	/*
	 * We're using a 32-bits bitmask stored in gd (env_has_init)
	 * using the above enum value as the bit index. We need to
	 * make sure that we're not overflowing it.
	 */
	BUILD_BUG_ON(ENVL_COUNT > BITS_PER_LONG);

	gd->env_has_init |= BIT(location);
}

/**
 * arch_env_get_location() - Returns the best env location for an arch
 * @op: operations performed on the environment
 * @prio: priority between the multiple environments, 0 being the
 *        highest priority
 *
 * This will return the preferred environment for the given priority.
 * This is overridable by architectures if they need to and has lower
 * priority than board side env_get_location() override.
 *
 * All implementations are free to use the operation, the priority and
 * any other data relevant to their choice, but must take into account
 * the fact that the lowest prority (0) is the most important location
 * in the system. The following locations should be returned by order
 * of descending priorities, from the highest to the lowest priority.
 *
 * Returns:
 * an enum env_location value on success, a negative error code otherwise
 */
__weak enum env_location arch_env_get_location(enum env_operation op, int prio)
{
	if (prio >= ARRAY_SIZE(env_locations))
		return ENVL_UNKNOWN;

	return env_locations[prio];
}

/**
 * env_get_location() - Returns the best env location for a board
 * @op: operations performed on the environment
 * @prio: priority between the multiple environments, 0 being the
 *        highest priority
 *
 * This will return the preferred environment for the given priority.
 * This is overridable by boards if they need to.
 *
 * All implementations are free to use the operation, the priority and
 * any other data relevant to their choice, but must take into account
 * the fact that the lowest prority (0) is the most important location
 * in the system. The following locations should be returned by order
 * of descending priorities, from the highest to the lowest priority.
 *
 * Returns:
 * an enum env_location value on success, a negative error code otherwise
 */
__weak enum env_location env_get_location(enum env_operation op, int prio)
{
	return arch_env_get_location(op, prio);
}

/**
 * env_driver_lookup() - Finds the most suited environment location
 * @op: operations performed on the environment
 * @prio: priority between the multiple environments, 0 being the
 *        highest priority
 *
 * This will try to find the available environment with the highest
 * priority in the system.
 *
 * Returns:
 * NULL on error, a pointer to a struct env_driver otherwise
 */
static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
{
	enum env_location loc = env_get_location(op, prio);
	struct env_driver *drv;

	if (loc == ENVL_UNKNOWN)
		return NULL;

	drv = _env_driver_lookup(loc);
	if (!drv) {
		debug("%s: No environment driver for location %d\n", __func__,
		      loc);
		return NULL;
	}

	return drv;
}

int env_load(void)
{
	struct env_driver *drv;
	int best_prio = -1;
	int prio;

	if (CONFIG_IS_ENABLED(ENV_WRITEABLE_LIST)) {
		/*
		 * When using a list of writeable variables, the baseline comes
		 * from the built-in default env. So load this first.
		 */
		env_set_default(NULL, 0);
	}

	for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
		int ret;

		if (!env_has_inited(drv->location))
			continue;

		printf("Loading Environment from %s... ", drv->name);
		/*
		 * In error case, the error message must be printed during
		 * drv->load() in some underlying API, and it must be exactly
		 * one message.
		 */
		ret = drv->load();
		if (!ret) {
			printf("OK\n");
			gd->env_load_prio = prio;

			return 0;
		} else if (ret == -ENOMSG) {
			/* Handle "bad CRC" case */
			if (best_prio == -1)
				best_prio = prio;
		} else {
			debug("Failed (%d)\n", ret);
		}
	}

	/*
	 * In case of invalid environment, we set the 'default' env location
	 * to the best choice, i.e.:
	 *   1. Environment location with bad CRC, if such location was found
	 *   2. Otherwise use the location with highest priority
	 *
	 * This way, next calls to env_save() will restore the environment
	 * at the right place.
	 */
	if (best_prio >= 0)
		debug("Selecting environment with bad CRC\n");
	else
		best_prio = 0;

	gd->env_load_prio = best_prio;

	return -ENODEV;
}

int env_reload(void)
{
	struct env_driver *drv;

	drv = env_driver_lookup(ENVOP_LOAD, gd->env_load_prio);
	if (drv) {
		int ret;

		printf("Loading Environment from %s... ", drv->name);

		if (!env_has_inited(drv->location)) {
			printf("not initialized\n");
			return -ENODEV;
		}

		ret = drv->load();
		if (ret)
			printf("Failed (%d)\n", ret);
		else
			printf("OK\n");

		if (!ret)
			return 0;
	}

	return -ENODEV;
}

int env_save(void)
{
	struct env_driver *drv;

	drv = env_driver_lookup(ENVOP_SAVE, gd->env_load_prio);
	if (drv) {
		int ret;

		printf("Saving Environment to %s... ", drv->name);
		if (!drv->save) {
			printf("not possible\n");
			return -ENODEV;
		}

		if (!env_has_inited(drv->location)) {
			printf("not initialized\n");
			return -ENODEV;
		}

		ret = drv->save();
		if (ret)
			printf("Failed (%d)\n", ret);
		else
			printf("OK\n");

		if (!ret)
			return 0;
	}

	return -ENODEV;
}

int env_erase(void)
{
	struct env_driver *drv;

	drv = env_driver_lookup(ENVOP_ERASE, gd->env_load_prio);
	if (drv) {
		int ret;

		if (!drv->erase) {
			printf("not possible\n");
			return -ENODEV;
		}

		if (!env_has_inited(drv->location)) {
			printf("not initialized\n");
			return -ENODEV;
		}

		printf("Erasing Environment on %s... ", drv->name);
		ret = drv->erase();
		if (ret)
			printf("Failed (%d)\n", ret);
		else
			printf("OK\n");

		if (!ret)
			return 0;
	}

	return -ENODEV;
}

int env_init(void)
{
	struct env_driver *drv;
	int ret = -ENOENT;
	int prio;

	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
		if (!drv->init || !(ret = drv->init()))
			env_set_inited(drv->location);
		if (ret == -ENOENT)
			env_set_inited(drv->location);

		debug("%s: Environment %s init done (ret=%d)\n", __func__,
		      drv->name, ret);

		if (gd->env_valid == ENV_INVALID)
			ret = -ENOENT;
	}

	if (!prio)
		return -ENODEV;

	if (ret == -ENOENT) {
		gd->env_addr = (ulong)&default_environment[0];
		gd->env_valid = ENV_VALID;

		return 0;
	}

	return ret;
}

int env_select(const char *name)
{
	struct env_driver *drv;
	const int n_ents = ll_entry_count(struct env_driver, env_driver);
	struct env_driver *entry;
	int prio;
	bool found = false;

	printf("Select Environment on %s: ", name);

	/* search ENV driver by name */
	drv = ll_entry_start(struct env_driver, env_driver);
	for (entry = drv; entry != drv + n_ents; entry++) {
		if (!strcmp(entry->name, name)) {
			found = true;
			break;
		}
	}

	if (!found) {
		printf("driver not found\n");
		return -ENODEV;
	}

	/* search priority by driver */
	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
		if (entry->location == env_get_location(ENVOP_LOAD, prio)) {
			/* when priority change, reset the ENV flags */
			if (gd->env_load_prio != prio) {
				gd->env_load_prio = prio;
				gd->env_valid = ENV_INVALID;
				gd->flags &= ~GD_FLG_ENV_DEFAULT;
			}
			printf("OK\n");
			return 0;
		}
	}
	printf("priority not found\n");

	return -ENODEV;
}
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
c9d728dd SG	2	/*
	3	* Copyright (C) 2017 Google, Inc
	4	* Written by Simon Glass <[email protected]>
c9d728dd SG	5	*/
	6
	7	#include <common.h>
4bfd1f5d	8	#include <env.h>
f3998fdc	9	#include <env_internal.h>
f7ae49fc	10	#include <log.h>
401d1c4f	11	#include <asm/global_data.h>
cd93d625	12	#include <linux/bitops.h>
eb41d8a1	13	#include <linux/bug.h>
c9d728dd SG	14
	15	DECLARE_GLOBAL_DATA_PTR;
	16
7bcdf195 SDPP	17	#if defined(CONFIG_NEEDS_MANUAL_RELOC)
	18	void env_fix_drivers(void)
	19	{
	20	struct env_driver *drv;
	21	const int n_ents = ll_entry_count(struct env_driver, env_driver);
	22	struct env_driver *entry;
	23
	24	drv = ll_entry_start(struct env_driver, env_driver);
	25	for (entry = drv; entry != drv + n_ents; entry++) {
	26	if (entry->name)
	27	entry->name += gd->reloc_off;
	28	if (entry->load)
	29	entry->load += gd->reloc_off;
	30	if (entry->save)
	31	entry->save += gd->reloc_off;
cd121bdb FW	32	if (entry->erase)
cd121bdb FW	33	entry->erase += gd->reloc_off;
7bcdf195 SDPP	34	if (entry->init)
	35	entry->init += gd->reloc_off;
	36	}
	37	}
	38	#endif
	39
52746c43	40	static struct env_driver *_env_driver_lookup(enum env_location loc)
c9d728dd SG	41	{
	42	struct env_driver *drv;
	43	const int n_ents = ll_entry_count(struct env_driver, env_driver);
	44	struct env_driver *entry;
	45
	46	drv = ll_entry_start(struct env_driver, env_driver);
	47	for (entry = drv; entry != drv + n_ents; entry++) {
	48	if (loc == entry->location)
	49	return entry;
	50	}
	51
	52	/* Not found */
	53	return NULL;
	54	}
	55
7d714a24 MR	56	static enum env_location env_locations[] = {
	57	#ifdef CONFIG_ENV_IS_IN_EEPROM
	58	ENVL_EEPROM,
	59	#endif
	60	#ifdef CONFIG_ENV_IS_IN_EXT4
	61	ENVL_EXT4,
	62	#endif
	63	#ifdef CONFIG_ENV_IS_IN_FAT
	64	ENVL_FAT,
	65	#endif
	66	#ifdef CONFIG_ENV_IS_IN_FLASH
	67	ENVL_FLASH,
	68	#endif
	69	#ifdef CONFIG_ENV_IS_IN_MMC
	70	ENVL_MMC,
	71	#endif
	72	#ifdef CONFIG_ENV_IS_IN_NAND
	73	ENVL_NAND,
	74	#endif
	75	#ifdef CONFIG_ENV_IS_IN_NVRAM
	76	ENVL_NVRAM,
	77	#endif
	78	#ifdef CONFIG_ENV_IS_IN_REMOTE
	79	ENVL_REMOTE,
	80	#endif
	81	#ifdef CONFIG_ENV_IS_IN_SPI_FLASH
	82	ENVL_SPI_FLASH,
	83	#endif
	84	#ifdef CONFIG_ENV_IS_IN_UBI
	85	ENVL_UBI,
	86	#endif
	87	#ifdef CONFIG_ENV_IS_NOWHERE
	88	ENVL_NOWHERE,
	89	#endif
	90	};
	91
1d446087 MR	92	static bool env_has_inited(enum env_location location)
	93	{
	94	return gd->env_has_init & BIT(location);
	95	}
	96
	97	static void env_set_inited(enum env_location location)
	98	{
	99	/*
	100	* We're using a 32-bits bitmask stored in gd (env_has_init)
	101	* using the above enum value as the bit index. We need to
	102	* make sure that we're not overflowing it.
	103	*/
d5a6a5a9	104	BUILD_BUG_ON(ENVL_COUNT > BITS_PER_LONG);
1d446087 MR	105
	106	gd->env_has_init \|= BIT(location);
	107	}
	108
8a3a7e22	109	/**
de70e887	110	* arch_env_get_location() - Returns the best env location for an arch
8a3a7e22 MR	111	* @op: operations performed on the environment
	112	* @prio: priority between the multiple environments, 0 being the
	113	* highest priority
	114	*
	115	* This will return the preferred environment for the given priority.
de70e887 MV	116	* This is overridable by architectures if they need to and has lower
de70e887 MV	117	* priority than board side env_get_location() override.
8a3a7e22 MR	118	*
	119	* All implementations are free to use the operation, the priority and
	120	* any other data relevant to their choice, but must take into account
	121	* the fact that the lowest prority (0) is the most important location
	122	* in the system. The following locations should be returned by order
	123	* of descending priorities, from the highest to the lowest priority.
	124	*
	125	* Returns:
	126	* an enum env_location value on success, a negative error code otherwise
	127	*/
de70e887	128	__weak enum env_location arch_env_get_location(enum env_operation op, int prio)
c9d728dd	129	{
d30ba231 NF	130	if (prio >= ARRAY_SIZE(env_locations))
	131	return ENVL_UNKNOWN;
	132
d30ba231	133	return env_locations[prio];
c9d728dd SG	134	}
c9d728dd SG	135
de70e887 MV	136	/**
	137	* env_get_location() - Returns the best env location for a board
	138	* @op: operations performed on the environment
	139	* @prio: priority between the multiple environments, 0 being the
	140	* highest priority
	141	*
	142	* This will return the preferred environment for the given priority.
	143	* This is overridable by boards if they need to.
	144	*
	145	* All implementations are free to use the operation, the priority and
	146	* any other data relevant to their choice, but must take into account
	147	* the fact that the lowest prority (0) is the most important location
	148	* in the system. The following locations should be returned by order
	149	* of descending priorities, from the highest to the lowest priority.
	150	*
	151	* Returns:
	152	* an enum env_location value on success, a negative error code otherwise
	153	*/
	154	__weak enum env_location env_get_location(enum env_operation op, int prio)
	155	{
	156	return arch_env_get_location(op, prio);
	157	}
8a3a7e22 MR	158
	159	/**
	160	* env_driver_lookup() - Finds the most suited environment location
	161	* @op: operations performed on the environment
	162	* @prio: priority between the multiple environments, 0 being the
	163	* highest priority
	164	*
	165	* This will try to find the available environment with the highest
	166	* priority in the system.
	167	*
	168	* Returns:
	169	* NULL on error, a pointer to a struct env_driver otherwise
	170	*/
	171	static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
c9d728dd	172	{
8a3a7e22	173	enum env_location loc = env_get_location(op, prio);
c9d728dd SG	174	struct env_driver *drv;
c9d728dd SG	175
8a3a7e22 MR	176	if (loc == ENVL_UNKNOWN)
	177	return NULL;
	178
52746c43	179	drv = _env_driver_lookup(loc);
c9d728dd SG	180	if (!drv) {
	181	debug("%s: No environment driver for location %d\n", __func__,
	182	loc);
	183	return NULL;
	184	}
	185
	186	return drv;
	187	}
	188
c9d728dd SG	189	int env_load(void)
c9d728dd SG	190	{
8a3a7e22	191	struct env_driver *drv;
293a172b	192	int best_prio = -1;
8a3a7e22	193	int prio;
c9d728dd	194
5ab81058 JK	195	if (CONFIG_IS_ENABLED(ENV_WRITEABLE_LIST)) {
	196	/*
	197	* When using a list of writeable variables, the baseline comes
	198	* from the built-in default env. So load this first.
	199	*/
	200	env_set_default(NULL, 0);
	201	}
	202
8a3a7e22 MR	203	for (prio = 0; (drv = env_driver_lookup(ENVOP_LOAD, prio)); prio++) {
	204	int ret;
	205
1d446087 MR	206	if (!env_has_inited(drv->location))
	207	continue;
	208
3574ba01	209	printf("Loading Environment from %s... ", drv->name);
13bbfb4a SP	210	/*
	211	* In error case, the error message must be printed during
	212	* drv->load() in some underlying API, and it must be exactly
	213	* one message.
	214	*/
8a3a7e22	215	ret = drv->load();
293a172b	216	if (!ret) {
3574ba01	217	printf("OK\n");
6d8d8400 PD	218	gd->env_load_prio = prio;
6d8d8400 PD	219
8a3a7e22	220	return 0;
293a172b SP	221	} else if (ret == -ENOMSG) {
	222	/* Handle "bad CRC" case */
	223	if (best_prio == -1)
	224	best_prio = prio;
	225	} else {
	226	debug("Failed (%d)\n", ret);
13bbfb4a	227	}
c9d728dd SG	228	}
c9d728dd SG	229
d30ba231 NF	230	/*
d30ba231 NF	231	* In case of invalid environment, we set the 'default' env location
293a172b SP	232	* to the best choice, i.e.:
	233	* 1. Environment location with bad CRC, if such location was found
	234	* 2. Otherwise use the location with highest priority
	235	*
	236	* This way, next calls to env_save() will restore the environment
	237	* at the right place.
d30ba231	238	*/
293a172b SP	239	if (best_prio >= 0)
	240	debug("Selecting environment with bad CRC\n");
	241	else
	242	best_prio = 0;
6d8d8400 PD	243
6d8d8400 PD	244	gd->env_load_prio = best_prio;
d30ba231	245
8a3a7e22	246	return -ENODEV;
c9d728dd SG	247	}
c9d728dd SG	248
0115dd3a PD	249	int env_reload(void)
	250	{
	251	struct env_driver *drv;
	252
	253	drv = env_driver_lookup(ENVOP_LOAD, gd->env_load_prio);
	254	if (drv) {
	255	int ret;
	256
	257	printf("Loading Environment from %s... ", drv->name);
	258
	259	if (!env_has_inited(drv->location)) {
	260	printf("not initialized\n");
	261	return -ENODEV;
	262	}
	263
	264	ret = drv->load();
	265	if (ret)
	266	printf("Failed (%d)\n", ret);
	267	else
	268	printf("OK\n");
	269
	270	if (!ret)
	271	return 0;
	272	}
	273
	274	return -ENODEV;
	275	}
	276
c9d728dd SG	277	int env_save(void)
c9d728dd SG	278	{
8a3a7e22	279	struct env_driver *drv;
c9d728dd	280
d30ba231 NF	281	drv = env_driver_lookup(ENVOP_SAVE, gd->env_load_prio);
d30ba231 NF	282	if (drv) {
8a3a7e22 MR	283	int ret;
8a3a7e22 MR	284
8968288c PD	285	printf("Saving Environment to %s... ", drv->name);
	286	if (!drv->save) {
	287	printf("not possible\n");
d30ba231	288	return -ENODEV;
8968288c	289	}
8a3a7e22	290
8968288c PD	291	if (!env_has_inited(drv->location)) {
8968288c PD	292	printf("not initialized\n");
d30ba231	293	return -ENODEV;
8968288c	294	}
1d446087	295
8a3a7e22	296	ret = drv->save();
3574ba01 MR	297	if (ret)
	298	printf("Failed (%d)\n", ret);
	299	else
	300	printf("OK\n");
	301
8a3a7e22 MR	302	if (!ret)
8a3a7e22 MR	303	return 0;
c9d728dd SG	304	}
c9d728dd SG	305
8a3a7e22	306	return -ENODEV;
c9d728dd SG	307	}
c9d728dd SG	308
cd121bdb FW	309	int env_erase(void)
	310	{
	311	struct env_driver *drv;
	312
	313	drv = env_driver_lookup(ENVOP_ERASE, gd->env_load_prio);
	314	if (drv) {
	315	int ret;
	316
1c44d108 PD	317	if (!drv->erase) {
1c44d108 PD	318	printf("not possible\n");
cd121bdb	319	return -ENODEV;
1c44d108	320	}
cd121bdb	321
1c44d108 PD	322	if (!env_has_inited(drv->location)) {
1c44d108 PD	323	printf("not initialized\n");
cd121bdb	324	return -ENODEV;
1c44d108	325	}
cd121bdb FW	326
	327	printf("Erasing Environment on %s... ", drv->name);
	328	ret = drv->erase();
	329	if (ret)
	330	printf("Failed (%d)\n", ret);
	331	else
	332	printf("OK\n");
	333
	334	if (!ret)
	335	return 0;
	336	}
	337
	338	return -ENODEV;
	339	}
	340
6eeae424	341	int env_init(void)
c9d728dd	342	{
8a3a7e22	343	struct env_driver *drv;
7938822a	344	int ret = -ENOENT;
8a3a7e22 MR	345	int prio;
	346
	347	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
1d446087 MR	348	if (!drv->init \|\| !(ret = drv->init()))
1d446087 MR	349	env_set_inited(drv->location);
46ce9e77 HS	350	if (ret == -ENOENT)
46ce9e77 HS	351	env_set_inited(drv->location);
8a3a7e22	352
1d446087	353	debug("%s: Environment %s init done (ret=%d)\n", __func__,
8a3a7e22	354	drv->name, ret);
8d61237e	355
5c7399ec MV	356	if (gd->env_valid == ENV_INVALID)
5c7399ec MV	357	ret = -ENOENT;
8d61237e	358	}
8a3a7e22	359
5c7399ec MV	360	if (!prio)
	361	return -ENODEV;
	362
7938822a SG	363	if (ret == -ENOENT) {
7938822a SG	364	gd->env_addr = (ulong)&default_environment[0];
5c7399ec	365	gd->env_valid = ENV_VALID;
7938822a SG	366
7938822a SG	367	return 0;
c9d728dd SG	368	}
c9d728dd SG	369
8a3a7e22	370	return ret;
c9d728dd	371	}
a97d22eb PD	372
	373	int env_select(const char *name)
	374	{
	375	struct env_driver *drv;
	376	const int n_ents = ll_entry_count(struct env_driver, env_driver);
	377	struct env_driver *entry;
	378	int prio;
	379	bool found = false;
	380
	381	printf("Select Environment on %s: ", name);
	382
	383	/* search ENV driver by name */
	384	drv = ll_entry_start(struct env_driver, env_driver);
	385	for (entry = drv; entry != drv + n_ents; entry++) {
	386	if (!strcmp(entry->name, name)) {
	387	found = true;
	388	break;
	389	}
	390	}
	391
	392	if (!found) {
	393	printf("driver not found\n");
	394	return -ENODEV;
	395	}
	396
	397	/* search priority by driver */
	398	for (prio = 0; (drv = env_driver_lookup(ENVOP_INIT, prio)); prio++) {
	399	if (entry->location == env_get_location(ENVOP_LOAD, prio)) {
	400	/* when priority change, reset the ENV flags */
	401	if (gd->env_load_prio != prio) {
	402	gd->env_load_prio = prio;
	403	gd->env_valid = ENV_INVALID;
	404	gd->flags &= ~GD_FLG_ENV_DEFAULT;
	405	}
	406	printf("OK\n");
	407	return 0;
	408	}
	409	}
	410	printf("priority not found\n");
	411
	412	return -ENODEV;
	413	}