1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2022 - 2023 Rafał Miłecki <rafal@milecki.pl>
*/
#include <linux/crc32.h>
#include <linux/etherdevice.h>
#include <linux/export.h>
#include <linux/if_ether.h>
#include <linux/nvmem-consumer.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/slab.h>
#include "u-boot-env.h"
struct u_boot_env_image_single {
__le32 crc32;
uint8_t data[];
} __packed;
struct u_boot_env_image_redundant {
__le32 crc32;
u8 mark;
uint8_t data[];
} __packed;
struct u_boot_env_image_broadcom {
__le32 magic;
__le32 len;
__le32 crc32;
DECLARE_FLEX_ARRAY(uint8_t, data);
} __packed;
static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index,
unsigned int offset, void *buf, size_t bytes)
{
u8 mac[ETH_ALEN];
if (bytes != 3 * ETH_ALEN - 1)
return -EINVAL;
if (!mac_pton(buf, mac))
return -EINVAL;
if (index)
eth_addr_add(mac, index);
ether_addr_copy(buf, mac);
return 0;
}
static int u_boot_env_parse_cells(struct device *dev, struct nvmem_device *nvmem, uint8_t *buf,
size_t data_offset, size_t data_len)
{
char *data = buf + data_offset;
char *var, *value, *eq;
for (var = data;
var < data + data_len && *var;
var = value + strlen(value) + 1) {
struct nvmem_cell_info info = {};
eq = strchr(var, '=');
if (!eq)
break;
*eq = '\0';
value = eq + 1;
info.name = devm_kstrdup(dev, var, GFP_KERNEL);
if (!info.name)
return -ENOMEM;
info.offset = data_offset + value - data;
info.bytes = strlen(value);
info.np = of_get_child_by_name(dev->of_node, info.name);
if (!strcmp(var, "ethaddr")) {
info.raw_len = strlen(value);
info.bytes = ETH_ALEN;
info.read_post_process = u_boot_env_read_post_process_ethaddr;
}
nvmem_add_one_cell(nvmem, &info);
}
return 0;
}
int u_boot_env_parse(struct device *dev, struct nvmem_device *nvmem,
enum u_boot_env_format format)
{
size_t crc32_data_offset;
size_t crc32_data_len;
size_t crc32_offset;
__le32 *crc32_addr;
size_t data_offset;
size_t data_len;
size_t dev_size;
uint32_t crc32;
uint32_t calc;
uint8_t *buf;
int bytes;
int err;
dev_size = nvmem_dev_size(nvmem);
buf = kzalloc(dev_size, GFP_KERNEL);
if (!buf) {
err = -ENOMEM;
goto err_out;
}
bytes = nvmem_device_read(nvmem, 0, dev_size, buf);
if (bytes < 0) {
err = bytes;
goto err_kfree;
} else if (bytes != dev_size) {
err = -EIO;
goto err_kfree;
}
switch (format) {
case U_BOOT_FORMAT_SINGLE:
crc32_offset = offsetof(struct u_boot_env_image_single, crc32);
crc32_data_offset = offsetof(struct u_boot_env_image_single, data);
data_offset = offsetof(struct u_boot_env_image_single, data);
break;
case U_BOOT_FORMAT_REDUNDANT:
crc32_offset = offsetof(struct u_boot_env_image_redundant, crc32);
crc32_data_offset = offsetof(struct u_boot_env_image_redundant, data);
data_offset = offsetof(struct u_boot_env_image_redundant, data);
break;
case U_BOOT_FORMAT_BROADCOM:
crc32_offset = offsetof(struct u_boot_env_image_broadcom, crc32);
crc32_data_offset = offsetof(struct u_boot_env_image_broadcom, data);
data_offset = offsetof(struct u_boot_env_image_broadcom, data);
break;
}
if (dev_size < data_offset) {
dev_err(dev, "Device too small for u-boot-env\n");
err = -EIO;
goto err_kfree;
}
crc32_addr = (__le32 *)(buf + crc32_offset);
crc32 = le32_to_cpu(*crc32_addr);
crc32_data_len = dev_size - crc32_data_offset;
data_len = dev_size - data_offset;
calc = crc32(~0, buf + crc32_data_offset, crc32_data_len) ^ ~0L;
if (calc != crc32) {
dev_err(dev, "Invalid calculated CRC32: 0x%08x (expected: 0x%08x)\n", calc, crc32);
err = -EINVAL;
goto err_kfree;
}
buf[dev_size - 1] = '\0';
err = u_boot_env_parse_cells(dev, nvmem, buf, data_offset, data_len);
err_kfree:
kfree(buf);
err_out:
return err;
}
EXPORT_SYMBOL_GPL(u_boot_env_parse);
static int u_boot_env_add_cells(struct nvmem_layout *layout)
{
struct device *dev = &layout->dev;
enum u_boot_env_format format;
format = (uintptr_t)device_get_match_data(dev);
return u_boot_env_parse(dev, layout->nvmem, format);
}
static int u_boot_env_probe(struct nvmem_layout *layout)
{
layout->add_cells = u_boot_env_add_cells;
return nvmem_layout_register(layout);
}
static void u_boot_env_remove(struct nvmem_layout *layout)
{
nvmem_layout_unregister(layout);
}
static const struct of_device_id u_boot_env_of_match_table[] = {
{ .compatible = "u-boot,env", .data = (void *)U_BOOT_FORMAT_SINGLE, },
{ .compatible = "u-boot,env-redundant-bool", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
{ .compatible = "u-boot,env-redundant-count", .data = (void *)U_BOOT_FORMAT_REDUNDANT, },
{ .compatible = "brcm,env", .data = (void *)U_BOOT_FORMAT_BROADCOM, },
{},
};
static struct nvmem_layout_driver u_boot_env_layout = {
.driver = {
.name = "u-boot-env-layout",
.of_match_table = u_boot_env_of_match_table,
},
.probe = u_boot_env_probe,
.remove = u_boot_env_remove,
};
module_nvmem_layout_driver(u_boot_env_layout);
MODULE_AUTHOR("Rafał Miłecki");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);
MODULE_DESCRIPTION("NVMEM layout driver for U-Boot environment variables");
|
