2 * (C) Copyright 2000-2010
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
6 * Andreas Heppel <aheppel@sysgo.de>
8 * SPDX-License-Identifier: GPL-2.0+
12 * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
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.
29 #include <environment.h>
30 #include <linux/stddef.h>
34 DECLARE_GLOBAL_DATA_PTR;
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);
41 env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
44 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
45 static uchar env_nvram_get_char(int index)
49 nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
55 static void env_nvram_load(void)
57 char buf[CONFIG_ENV_SIZE];
59 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
60 nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
62 memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
67 static int env_nvram_save(void)
72 rcode = env_export(&env_new);
76 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
77 nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
79 if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
86 * Initialize Environment use
88 * We are still running from ROM, so data use is limited
90 static int env_nvram_init(void)
92 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
96 nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
97 nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
99 if (crc32(0, data, ENV_SIZE) == crc) {
100 gd->env_addr = (ulong)CONFIG_ENV_ADDR + sizeof(long);
102 if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
103 gd->env_addr = (ulong)&env_ptr->data;
105 gd->env_valid = ENV_VALID;
107 gd->env_addr = (ulong)&default_environment[0];
114 U_BOOT_ENV_LOCATION(nvram) = {
115 .location = ENVL_NVRAM,
117 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
118 .get_char = env_nvram_get_char,
120 .load = env_nvram_load,
121 .save = env_save_ptr(env_nvram_save),
122 .init = env_nvram_init,