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 /** Call this function from overridden env_get_char_spec() if you need 45 * this functionality. 46 */ 47 int env_nvram_get_char(int index) 48 { 49 uchar c; 50 51 nvram_read(&c, CONFIG_ENV_ADDR + index, 1); 52 53 return c; 54 } 55 #endif 56 57 static int env_nvram_load(void) 58 { 59 char buf[CONFIG_ENV_SIZE]; 60 61 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE) 62 nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE); 63 #else 64 memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE); 65 #endif 66 return env_import(buf, 1); 67 } 68 69 static int env_nvram_save(void) 70 { 71 env_t env_new; 72 int rcode = 0; 73 74 rcode = env_export(&env_new); 75 if (rcode) 76 return rcode; 77 78 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE 79 nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE); 80 #else 81 if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL) 82 rcode = 1; 83 #endif 84 return rcode; 85 } 86 87 /* 88 * Initialize Environment use 89 * 90 * We are still running from ROM, so data use is limited 91 */ 92 static int env_nvram_init(void) 93 { 94 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE) 95 ulong crc; 96 uchar data[ENV_SIZE]; 97 98 nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong)); 99 nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE); 100 101 if (crc32(0, data, ENV_SIZE) == crc) { 102 gd->env_addr = (ulong)CONFIG_ENV_ADDR + sizeof(long); 103 #else 104 if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) { 105 gd->env_addr = (ulong)&env_ptr->data; 106 #endif 107 gd->env_valid = ENV_VALID; 108 } else { 109 gd->env_addr = (ulong)&default_environment[0]; 110 gd->env_valid = ENV_INVALID; 111 } 112 113 return 0; 114 } 115 116 U_BOOT_ENV_LOCATION(nvram) = { 117 .location = ENVL_NVRAM, 118 ENV_NAME("NVRAM") 119 .load = env_nvram_load, 120 .save = env_save_ptr(env_nvram_save), 121 .init = env_nvram_init, 122 }; 123