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