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 #include <common.h>
11 #include <command.h>
12 #include <eeprom.h>
13 #include <env.h>
14 #include <env_internal.h>
15 #include <asm/global_data.h>
16 #include <linux/stddef.h>
17 #include <u-boot/crc.h>
18 #include <search.h>
19 #include <errno.h>
20 #include <linux/compiler.h> /* for BUG_ON */
21
22 DECLARE_GLOBAL_DATA_PTR;
23
env_eeprom_load(void)24 static int env_eeprom_load(void)
25 {
26 char buf_env[CONFIG_ENV_SIZE];
27 unsigned int off = CONFIG_ENV_OFFSET;
28
29 #ifdef CONFIG_ENV_OFFSET_REDUND
30 ulong len, crc[2], crc_tmp;
31 unsigned int off_env[2];
32 uchar rdbuf[64], flags[2];
33 int i, crc_ok[2] = {0, 0};
34
35 eeprom_init(-1); /* prepare for EEPROM read/write */
36
37 off_env[0] = CONFIG_ENV_OFFSET;
38 off_env[1] = CONFIG_ENV_OFFSET_REDUND;
39
40 for (i = 0; i < 2; i++) {
41 /* read CRC */
42 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
43 off_env[i] + offsetof(env_t, crc),
44 (uchar *)&crc[i], sizeof(ulong));
45 /* read FLAGS */
46 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
47 off_env[i] + offsetof(env_t, flags),
48 (uchar *)&flags[i], sizeof(uchar));
49
50 crc_tmp = 0;
51 len = ENV_SIZE;
52 off = off_env[i] + offsetof(env_t, data);
53 while (len > 0) {
54 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
55
56 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR, off,
57 rdbuf, n);
58
59 crc_tmp = crc32(crc_tmp, rdbuf, n);
60 len -= n;
61 off += n;
62 }
63
64 if (crc_tmp == crc[i])
65 crc_ok[i] = 1;
66 }
67
68 if (!crc_ok[0] && !crc_ok[1]) {
69 gd->env_addr = 0;
70 gd->env_valid = ENV_INVALID;
71 } else if (crc_ok[0] && !crc_ok[1]) {
72 gd->env_valid = ENV_VALID;
73 } else if (!crc_ok[0] && crc_ok[1]) {
74 gd->env_valid = ENV_REDUND;
75 } else {
76 /* both ok - check serial */
77 if (flags[0] == ENV_REDUND_ACTIVE &&
78 flags[1] == ENV_REDUND_OBSOLETE)
79 gd->env_valid = ENV_VALID;
80 else if (flags[0] == ENV_REDUND_OBSOLETE &&
81 flags[1] == ENV_REDUND_ACTIVE)
82 gd->env_valid = ENV_REDUND;
83 else if (flags[0] == 0xFF && flags[1] == 0)
84 gd->env_valid = ENV_REDUND;
85 else if (flags[1] == 0xFF && flags[0] == 0)
86 gd->env_valid = ENV_VALID;
87 else /* flags are equal - almost impossible */
88 gd->env_valid = ENV_VALID;
89 }
90
91 #else /* CONFIG_ENV_OFFSET_REDUND */
92 ulong crc, len, new;
93 uchar rdbuf[64];
94
95 eeprom_init(-1); /* prepare for EEPROM read/write */
96
97 /* read old CRC */
98 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
99 CONFIG_ENV_OFFSET + offsetof(env_t, crc),
100 (uchar *)&crc, sizeof(ulong));
101
102 new = 0;
103 len = ENV_SIZE;
104 off = offsetof(env_t, data);
105 while (len > 0) {
106 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
107
108 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
109 CONFIG_ENV_OFFSET + off, rdbuf, n);
110 new = crc32(new, rdbuf, n);
111 len -= n;
112 off += n;
113 }
114
115 if (crc == new) {
116 gd->env_valid = ENV_VALID;
117 } else {
118 gd->env_valid = ENV_INVALID;
119 }
120 #endif /* CONFIG_ENV_OFFSET_REDUND */
121
122 off = CONFIG_ENV_OFFSET;
123 #ifdef CONFIG_ENV_OFFSET_REDUND
124 if (gd->env_valid == ENV_REDUND)
125 off = CONFIG_ENV_OFFSET_REDUND;
126 #endif
127
128 eeprom_read(CONFIG_SYS_I2C_EEPROM_ADDR,
129 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
130
131 return env_import(buf_env, 1, H_EXTERNAL);
132 }
133
env_eeprom_save(void)134 static int env_eeprom_save(void)
135 {
136 env_t env_new;
137 int rc;
138 unsigned int off = CONFIG_ENV_OFFSET;
139 #ifdef CONFIG_ENV_OFFSET_REDUND
140 unsigned int off_red = CONFIG_ENV_OFFSET_REDUND;
141 char flag_obsolete = ENV_REDUND_OBSOLETE;
142 #endif
143
144 rc = env_export(&env_new);
145 if (rc)
146 return rc;
147
148 #ifdef CONFIG_ENV_OFFSET_REDUND
149 if (gd->env_valid == ENV_VALID) {
150 off = CONFIG_ENV_OFFSET_REDUND;
151 off_red = CONFIG_ENV_OFFSET;
152 }
153
154 env_new.flags = ENV_REDUND_ACTIVE;
155 #endif
156
157 rc = eeprom_write(CONFIG_SYS_I2C_EEPROM_ADDR,
158 off, (uchar *)&env_new, CONFIG_ENV_SIZE);
159
160 #ifdef CONFIG_ENV_OFFSET_REDUND
161 if (rc == 0) {
162 eeprom_write(CONFIG_SYS_I2C_EEPROM_ADDR,
163 off_red + offsetof(env_t, flags),
164 (uchar *)&flag_obsolete, 1);
165
166 if (gd->env_valid == ENV_VALID)
167 gd->env_valid = ENV_REDUND;
168 else
169 gd->env_valid = ENV_VALID;
170 }
171 #endif
172 return rc;
173 }
174
175 U_BOOT_ENV_LOCATION(eeprom) = {
176 .location = ENVL_EEPROM,
177 ENV_NAME("EEPROM")
178 .load = env_eeprom_load,
179 .save = env_save_ptr(env_eeprom_save),
180 };
181