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 <environment.h> 29 #include <linux/stddef.h> 30 #include <search.h> 31 #include <errno.h> 32 33 DECLARE_GLOBAL_DATA_PTR; 34 35 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE 36 extern void *nvram_read(void *dest, const long src, size_t count); 37 extern void nvram_write(long dest, const void *src, size_t count); 38 #else 39 env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR; 40 #endif 41 42 #ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE 43 /** Call this function from overridden env_get_char_spec() if you need 44 * this functionality. 45 */ 46 int env_nvram_get_char(int index) 47 { 48 uchar c; 49 50 nvram_read(&c, CONFIG_ENV_ADDR + index, 1); 51 52 return c; 53 } 54 #endif 55 56 static int env_nvram_load(void) 57 { 58 char buf[CONFIG_ENV_SIZE]; 59 60 #if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE) 61 nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE); 62 #else 63 memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE); 64 #endif 65 return env_import(buf, 1); 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 .load = env_nvram_load, 119 .save = env_save_ptr(env_nvram_save), 120 .init = env_nvram_init, 121 }; 122