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