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
212
213
214
215
216
217
|
/*
* BCM47XX MTD partitioning
*
* Copyright © 2012 Rafał Miłecki <zajec5@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <asm/mach-bcm47xx/nvram.h>
/* 10 parts were found on sflash on Netgear WNDR4500 */
#define BCM47XXPART_MAX_PARTS 12
/*
* Amount of bytes we read when analyzing each block of flash memory.
* Set it big enough to allow detecting partition and reading important data.
*/
#define BCM47XXPART_BYTES_TO_READ 0x404
/* Magics */
#define BOARD_DATA_MAGIC 0x5246504D /* MPFR */
#define POT_MAGIC1 0x54544f50 /* POTT */
#define POT_MAGIC2 0x504f /* OP */
#define ML_MAGIC1 0x39685a42
#define ML_MAGIC2 0x26594131
#define TRX_MAGIC 0x30524448
struct trx_header {
uint32_t magic;
uint32_t length;
uint32_t crc32;
uint16_t flags;
uint16_t version;
uint32_t offset[3];
} __packed;
static void bcm47xxpart_add_part(struct mtd_partition *part, char *name,
u64 offset, uint32_t mask_flags)
{
part->name = name;
part->offset = offset;
part->mask_flags = mask_flags;
}
static int bcm47xxpart_parse(struct mtd_info *master,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct mtd_partition *parts;
uint8_t i, curr_part = 0;
uint32_t *buf;
size_t bytes_read;
uint32_t offset;
uint32_t blocksize = master->erasesize;
struct trx_header *trx;
int trx_part = -1;
int last_trx_part = -1;
if (blocksize <= 0x10000)
blocksize = 0x10000;
/* Alloc */
parts = kzalloc(sizeof(struct mtd_partition) * BCM47XXPART_MAX_PARTS,
GFP_KERNEL);
buf = kzalloc(BCM47XXPART_BYTES_TO_READ, GFP_KERNEL);
/* Parse block by block looking for magics */
for (offset = 0; offset <= master->size - blocksize;
offset += blocksize) {
/* Nothing more in higher memory */
if (offset >= 0x2000000)
break;
if (curr_part > BCM47XXPART_MAX_PARTS) {
pr_warn("Reached maximum number of partitions, scanning stopped!\n");
break;
}
/* Read beginning of the block */
if (mtd_read(master, offset, BCM47XXPART_BYTES_TO_READ,
&bytes_read, (uint8_t *)buf) < 0) {
pr_err("mtd_read error while parsing (offset: 0x%X)!\n",
offset);
continue;
}
/* CFE has small NVRAM at 0x400 */
if (buf[0x400 / 4] == NVRAM_HEADER) {
bcm47xxpart_add_part(&parts[curr_part++], "boot",
offset, MTD_WRITEABLE);
continue;
}
/* Standard NVRAM */
if (buf[0x000 / 4] == NVRAM_HEADER) {
bcm47xxpart_add_part(&parts[curr_part++], "nvram",
offset, 0);
continue;
}
/*
* board_data starts with board_id which differs across boards,
* but we can use 'MPFR' (hopefully) magic at 0x100
*/
if (buf[0x100 / 4] == BOARD_DATA_MAGIC) {
bcm47xxpart_add_part(&parts[curr_part++], "board_data",
offset, MTD_WRITEABLE);
continue;
}
/* POT(TOP) */
if (buf[0x000 / 4] == POT_MAGIC1 &&
(buf[0x004 / 4] & 0xFFFF) == POT_MAGIC2) {
bcm47xxpart_add_part(&parts[curr_part++], "POT", offset,
MTD_WRITEABLE);
continue;
}
/* ML */
if (buf[0x010 / 4] == ML_MAGIC1 &&
buf[0x014 / 4] == ML_MAGIC2) {
bcm47xxpart_add_part(&parts[curr_part++], "ML", offset,
MTD_WRITEABLE);
continue;
}
/* TRX */
if (buf[0x000 / 4] == TRX_MAGIC) {
trx = (struct trx_header *)buf;
trx_part = curr_part;
bcm47xxpart_add_part(&parts[curr_part++], "firmware",
offset, 0);
i = 0;
/* We have LZMA loader if offset[2] points to sth */
if (trx->offset[2]) {
bcm47xxpart_add_part(&parts[curr_part++],
"loader",
offset + trx->offset[i],
0);
i++;
}
bcm47xxpart_add_part(&parts[curr_part++], "linux",
offset + trx->offset[i], 0);
i++;
/*
* Pure rootfs size is known and can be calculated as:
* trx->length - trx->offset[i]. We don't fill it as
* we want to have jffs2 (overlay) in the same mtd.
*/
bcm47xxpart_add_part(&parts[curr_part++], "rootfs",
offset + trx->offset[i], 0);
i++;
last_trx_part = curr_part - 1;
/*
* We have whole TRX scanned, skip to the next part. Use
* roundown (not roundup), as the loop will increase
* offset in next step.
*/
offset = rounddown(offset + trx->length, blocksize);
continue;
}
}
kfree(buf);
/*
* Assume that partitions end at the beginning of the one they are
* followed by.
*/
for (i = 0; i < curr_part; i++) {
u64 next_part_offset = (i < curr_part - 1) ?
parts[i + 1].offset : master->size;
parts[i].size = next_part_offset - parts[i].offset;
if (i == last_trx_part && trx_part >= 0)
parts[trx_part].size = next_part_offset -
parts[trx_part].offset;
}
*pparts = parts;
return curr_part;
};
static struct mtd_part_parser bcm47xxpart_mtd_parser = {
.owner = THIS_MODULE,
.parse_fn = bcm47xxpart_parse,
.name = "bcm47xxpart",
};
static int __init bcm47xxpart_init(void)
{
return register_mtd_parser(&bcm47xxpart_mtd_parser);
}
static void __exit bcm47xxpart_exit(void)
{
deregister_mtd_parser(&bcm47xxpart_mtd_parser);
}
module_init(bcm47xxpart_init);
module_exit(bcm47xxpart_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MTD partitioning for BCM47XX flash memories");
|
