1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Internal environment header file. This includes direct access to environment
4  * information such as its size and offset, direct access to the default
5  * environment and embedded environment (if used). It also provides environment
6  * drivers with various declarations.
7  *
8  * It should not be included by board files, drivers and code other than that
9  * related to the environment implementation.
10  *
11  * (C) Copyright 2002
12  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
13  */
14 
15 #ifndef _ENV_INTERNAL_H_
16 #define _ENV_INTERNAL_H_
17 
18 #include <linux/kconfig.h>
19 
20 /**************************************************************************
21  *
22  * The "environment" is stored as a list of '\0' terminated
23  * "name=value" strings. The end of the list is marked by a double
24  * '\0'. New entries are always added at the end. Deleting an entry
25  * shifts the remaining entries to the front. Replacing an entry is a
26  * combination of deleting the old value and adding the new one.
27  *
28  * The environment is preceded by a 32 bit CRC over the data part.
29  *
30  *************************************************************************/
31 
32 #if defined(CONFIG_ENV_IS_IN_FLASH)
33 # if	defined(CONFIG_ENV_ADDR_REDUND) && \
34 	((CONFIG_ENV_ADDR >= CONFIG_SYS_MONITOR_BASE) &&		\
35 	(CONFIG_ENV_ADDR_REDUND + CONFIG_ENV_SIZE) <=		\
36 	(CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN))
37 #  define ENV_IS_EMBEDDED
38 # endif
39 # if	(CONFIG_ENV_ADDR >= CONFIG_SYS_MONITOR_BASE) &&		\
40 	(CONFIG_ENV_ADDR + CONFIG_ENV_SIZE) <=			\
41 	(CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN)
42 #  define ENV_IS_EMBEDDED
43 # endif
44 #endif	/* CONFIG_ENV_IS_IN_FLASH */
45 
46 #if defined(CONFIG_ENV_IS_IN_NAND)
47 # if defined(CONFIG_ENV_OFFSET_OOB)
48 #  ifdef CONFIG_ENV_OFFSET_REDUND
49 #   error "CONFIG_ENV_OFFSET_REDUND is not supported when CONFIG_ENV_OFFSET_OOB"
50 #   error "is set"
51 #  endif
52 extern unsigned long nand_env_oob_offset;
53 # endif /* CONFIG_ENV_OFFSET_OOB */
54 #endif /* CONFIG_ENV_IS_IN_NAND */
55 
56 #include "compiler.h"
57 
58 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
59 # define ENV_HEADER_SIZE	(sizeof(uint32_t) + 1)
60 #else
61 # define ENV_HEADER_SIZE	(sizeof(uint32_t))
62 #endif
63 
64 #define ENV_SIZE (CONFIG_ENV_SIZE - ENV_HEADER_SIZE)
65 
66 /*
67  * If the environment is in RAM, allocate extra space for it in the malloc
68  * region.
69  */
70 #if defined(ENV_IS_EMBEDDED)
71 #define TOTAL_MALLOC_LEN	CONFIG_SYS_MALLOC_LEN
72 #elif (CONFIG_ENV_ADDR + CONFIG_ENV_SIZE < CONFIG_SYS_MONITOR_BASE) || \
73       (CONFIG_ENV_ADDR >= CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN) || \
74       defined(CONFIG_ENV_IS_IN_NVRAM)
75 #define	TOTAL_MALLOC_LEN	(CONFIG_SYS_MALLOC_LEN + CONFIG_ENV_SIZE)
76 #else
77 #define	TOTAL_MALLOC_LEN	CONFIG_SYS_MALLOC_LEN
78 #endif
79 
80 typedef struct environment_s {
81 	uint32_t	crc;		/* CRC32 over data bytes	*/
82 #ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
83 	unsigned char	flags;		/* active/obsolete flags ENVF_REDUND_ */
84 #endif
85 	unsigned char	data[ENV_SIZE]; /* Environment data		*/
86 } env_t;
87 
88 #ifdef ENV_IS_EMBEDDED
89 extern env_t embedded_environment;
90 #endif /* ENV_IS_EMBEDDED */
91 
92 #ifdef DEFAULT_ENV_IS_RW
93 extern char default_environment[];
94 #else
95 extern const char default_environment[];
96 #endif
97 
98 #ifndef DO_DEPS_ONLY
99 
100 #include <env_attr.h>
101 #include <env_callback.h>
102 #include <env_flags.h>
103 #include <search.h>
104 
105 enum env_location {
106 	ENVL_UNKNOWN,
107 	ENVL_EEPROM,
108 	ENVL_EXT4,
109 	ENVL_FAT,
110 	ENVL_FLASH,
111 	ENVL_MMC,
112 	ENVL_NAND,
113 	ENVL_NVRAM,
114 	ENVL_ONENAND,
115 	ENVL_REMOTE,
116 	ENVL_SPI_FLASH,
117 	ENVL_UBI,
118 	ENVL_NOWHERE,
119 
120 	ENVL_COUNT,
121 };
122 
123 /* value for the various operations we want to perform on the env */
124 enum env_operation {
125 	ENVOP_GET_CHAR,	/* we want to call the get_char function */
126 	ENVOP_INIT,	/* we want to call the init function */
127 	ENVOP_LOAD,	/* we want to call the load function */
128 	ENVOP_SAVE,	/* we want to call the save function */
129 	ENVOP_ERASE,	/* we want to call the erase function */
130 };
131 
132 struct env_driver {
133 	const char *name;
134 	enum env_location location;
135 
136 	/**
137 	 * load() - Load the environment from storage
138 	 *
139 	 * This method is required for loading environment
140 	 *
141 	 * @return 0 if OK, -ve on error
142 	 */
143 	int (*load)(void);
144 
145 	/**
146 	 * save() - Save the environment to storage
147 	 *
148 	 * This method is required for 'saveenv' to work.
149 	 *
150 	 * @return 0 if OK, -ve on error
151 	 */
152 	int (*save)(void);
153 
154 	/**
155 	 * erase() - Erase the environment on storage
156 	 *
157 	 * This method is optional and required for 'eraseenv' to work.
158 	 *
159 	 * @return 0 if OK, -ve on error
160 	 */
161 	int (*erase)(void);
162 
163 	/**
164 	 * init() - Set up the initial pre-relocation environment
165 	 *
166 	 * This method is optional.
167 	 *
168 	 * @return 0 if OK, -ENOENT if no initial environment could be found,
169 	 * other -ve on error
170 	 */
171 	int (*init)(void);
172 };
173 
174 /* Declare a new environment location driver */
175 #define U_BOOT_ENV_LOCATION(__name)					\
176 	ll_entry_declare(struct env_driver, __name, env_driver)
177 
178 /* Declare the name of a location */
179 #ifdef CONFIG_CMD_SAVEENV
180 #define ENV_NAME(_name) .name = _name,
181 #else
182 #define ENV_NAME(_name)
183 #endif
184 
185 #ifdef CONFIG_CMD_SAVEENV
186 #define env_save_ptr(x) x
187 #else
188 #define env_save_ptr(x) NULL
189 #endif
190 
191 #define ENV_SAVE_PTR(x) (CONFIG_IS_ENABLED(SAVEENV) ? (x) : NULL)
192 #define ENV_ERASE_PTR(x) (IS_ENABLED(CONFIG_CMD_ERASEENV) ? (x) : NULL)
193 
194 extern struct hsearch_data env_htab;
195 
196 /**
197  * env_ext4_get_intf() - Provide the interface for env in EXT4
198  *
199  * It is a weak function allowing board to overidde the default interface for
200  * U-Boot env in EXT4: CONFIG_ENV_EXT4_INTERFACE
201  *
202  * Return: string of interface, empty if not supported
203  */
204 const char *env_ext4_get_intf(void);
205 
206 /**
207  * env_ext4_get_dev_part() - Provide the device and partition for env in EXT4
208  *
209  * It is a weak function allowing board to overidde the default device and
210  * partition used for U-Boot env in EXT4: CONFIG_ENV_EXT4_DEVICE_AND_PART
211  *
212  * Return: string of device and partition
213  */
214 const char *env_ext4_get_dev_part(void);
215 
216 /**
217  * arch_env_get_location()- Provide the best location for the U-Boot environment
218  *
219  * It is a weak function allowing board to overidde the environment location
220  * on architecture level. This has lower priority than env_get_location(),
221  * which can be defined on board level.
222  *
223  * @op: operations performed on the environment
224  * @prio: priority between the multiple environments, 0 being the
225  *        highest priority
226  * Return:  an enum env_location value on success, or -ve error code.
227  */
228 enum env_location arch_env_get_location(enum env_operation op, int prio);
229 
230 /**
231  * env_get_location()- Provide the best location for the U-Boot environment
232  *
233  * It is a weak function allowing board to overidde the environment location
234  * on board level. This has higher priority than arch_env_get_location(),
235  * which can be defined on architecture level.
236  *
237  * @op: operations performed on the environment
238  * @prio: priority between the multiple environments, 0 being the
239  *        highest priority
240  * Return:  an enum env_location value on success, or -ve error code.
241  */
242 enum env_location env_get_location(enum env_operation op, int prio);
243 
244 /**
245  * env_fat_get_intf() - Provide the interface for env in FAT
246  *
247  * It is a weak function allowing board to overidde the default interface for
248  * U-Boot env in FAT: CONFIG_ENV_FAT_INTERFACE
249  *
250  * Return: string of interface, empty if not supported
251  */
252 const char *env_fat_get_intf(void);
253 
254 /**
255  * env_fat_get_dev_part() - Provide the device and partition for env in FAT
256  *
257  * It is a weak function allowing board to overidde the default device and
258  * partition used for U-Boot env in FAT: CONFIG_ENV_FAT_DEVICE_AND_PART
259  *
260  * Return: string of device and partition
261  */
262 char *env_fat_get_dev_part(void);
263 #endif /* DO_DEPS_ONLY */
264 
265 #endif /* _ENV_INTERNAL_H_ */
266