xref: /openbmc/u-boot/env/nvram.c (revision 32f11829)
1 /*
2  * (C) Copyright 2000-2010
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
6  * Andreas Heppel <aheppel@sysgo.de>
7 
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 /*
12  * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
13  *
14  * It might not be possible in all cases to use 'memcpy()' to copy
15  * the environment to NVRAM, as the NVRAM might not be mapped into
16  * the memory space. (I.e. this is the case for the BAB750). In those
17  * cases it might be possible to access the NVRAM using a different
18  * method. For example, the RTC on the BAB750 is accessible in IO
19  * space using its address and data registers. To enable usage of
20  * NVRAM in those cases I invented the functions 'nvram_read()' and
21  * 'nvram_write()', which will be activated upon the configuration
22  * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
23  * strongly dependent on the used HW, and must be redefined for each
24  * board that wants to use them.
25  */
26 
27 #include <common.h>
28 #include <command.h>
29 #include <environment.h>
30 #include <linux/stddef.h>
31 #include <search.h>
32 #include <errno.h>
33 
34 DECLARE_GLOBAL_DATA_PTR;
35 
36 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
37 extern void *nvram_read(void *dest, const long src, size_t count);
38 extern void nvram_write(long dest, const void *src, size_t count);
39 #else
40 env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
41 #endif
42 
43 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
44 static int env_nvram_get_char(int index)
45 {
46 	uchar c;
47 
48 	nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
49 
50 	return c;
51 }
52 #endif
53 
54 static int env_nvram_load(void)
55 {
56 	char buf[CONFIG_ENV_SIZE];
57 
58 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
59 	nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
60 #else
61 	memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
62 #endif
63 	env_import(buf, 1);
64 
65 	return 0;
66 }
67 
68 static int env_nvram_save(void)
69 {
70 	env_t	env_new;
71 	int	rcode = 0;
72 
73 	rcode = env_export(&env_new);
74 	if (rcode)
75 		return rcode;
76 
77 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
78 	nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
79 #else
80 	if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
81 		rcode = 1;
82 #endif
83 	return rcode;
84 }
85 
86 /*
87  * Initialize Environment use
88  *
89  * We are still running from ROM, so data use is limited
90  */
91 static int env_nvram_init(void)
92 {
93 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
94 	ulong crc;
95 	uchar data[ENV_SIZE];
96 
97 	nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
98 	nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
99 
100 	if (crc32(0, data, ENV_SIZE) == crc) {
101 		gd->env_addr	= (ulong)CONFIG_ENV_ADDR + sizeof(long);
102 #else
103 	if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
104 		gd->env_addr	= (ulong)&env_ptr->data;
105 #endif
106 		gd->env_valid = ENV_VALID;
107 	} else {
108 		gd->env_addr	= (ulong)&default_environment[0];
109 		gd->env_valid	= ENV_INVALID;
110 	}
111 
112 	return 0;
113 }
114 
115 U_BOOT_ENV_LOCATION(nvram) = {
116 	.location	= ENVL_NVRAM,
117 	ENV_NAME("NVRAM")
118 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
119 	.get_char	= env_nvram_get_char,
120 #endif
121 	.load		= env_nvram_load,
122 	.save		= env_save_ptr(env_nvram_save),
123 	.init		= env_nvram_init,
124 };
125