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
|
/*
* Copyright (C) Gabor Juhos <juhosg@openwrt.org>
*
* 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/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kmod.h>
#include <linux/root_dev.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/byteorder/generic.h>
#define PFX "trxsplit: "
#define TRX_MAGIC 0x30524448 /* "HDR0" */
#define TRX_VERSION 1
#define TRX_MAX_LEN 0x3A0000
#define TRX_NO_HEADER 0x1 /* do not write TRX header */
#define TRX_GZ_FILES 0x2 /* contains individual gzip files */
#define TRX_MAX_OFFSET 3
#define TRX_MIN_KERNEL_SIZE (256 * 1024)
struct trx_header {
u32 magic; /* "HDR0" */
u32 len; /* Length of file including header */
u32 crc32; /* 32-bit CRC from flag_version to end of file */
u32 flag_version; /* 0:15 flags, 16:31 version */
u32 offsets[TRX_MAX_OFFSET]; /* Offsets of partitions */
};
#define TRX_ALIGN 0x1000
static int trx_nr_parts;
static unsigned long trx_offset;
static struct mtd_info *trx_mtd;
static struct mtd_partition trx_parts[TRX_MAX_OFFSET];
static struct trx_header trx_hdr;
static int trxsplit_refresh_partitions(struct mtd_info *mtd);
static int trxsplit_checktrx(struct mtd_info *mtd, unsigned long offset)
{
size_t retlen;
int err;
err = mtd_read(mtd, offset, sizeof(trx_hdr), &retlen, (void *)&trx_hdr);
if (err) {
printk(KERN_ALERT PFX "unable to read from '%s'\n", mtd->name);
goto err_out;
}
if (retlen != sizeof(trx_hdr)) {
printk(KERN_ALERT PFX "reading failed on '%s'\n", mtd->name);
goto err_out;
}
trx_hdr.magic = le32_to_cpu(trx_hdr.magic);
trx_hdr.len = le32_to_cpu(trx_hdr.len);
trx_hdr.crc32 = le32_to_cpu(trx_hdr.crc32);
trx_hdr.flag_version = le32_to_cpu(trx_hdr.flag_version);
trx_hdr.offsets[0] = le32_to_cpu(trx_hdr.offsets[0]);
trx_hdr.offsets[1] = le32_to_cpu(trx_hdr.offsets[1]);
trx_hdr.offsets[2] = le32_to_cpu(trx_hdr.offsets[2]);
/* sanity checks */
if (trx_hdr.magic != TRX_MAGIC)
goto err_out;
if (trx_hdr.len > mtd->size - offset)
goto err_out;
/* TODO: add crc32 checking too? */
return 0;
err_out:
return -1;
}
static void trxsplit_findtrx(struct mtd_info *mtd)
{
unsigned long offset;
int err;
printk(KERN_INFO PFX "searching TRX header in '%s'\n", mtd->name);
err = 0;
for (offset = 0; offset < mtd->size; offset += TRX_ALIGN) {
err = trxsplit_checktrx(mtd, offset);
if (err == 0)
break;
}
if (err)
return;
printk(KERN_INFO PFX "TRX header found at 0x%lX\n", offset);
trx_mtd = mtd;
trx_offset = offset;
}
static void trxsplit_create_partitions(struct mtd_info *mtd)
{
struct mtd_partition *part = trx_parts;
int err;
int i;
for (i = 0; i < TRX_MAX_OFFSET; i++) {
part = &trx_parts[i];
if (trx_hdr.offsets[i] == 0)
continue;
part->offset = trx_offset + trx_hdr.offsets[i];
trx_nr_parts++;
}
for (i = 0; i < trx_nr_parts-1; i++)
trx_parts[i].size = trx_parts[i+1].offset - trx_parts[i].offset;
trx_parts[i].size = mtd->size - trx_parts[i].offset;
i = 0;
part = &trx_parts[i];
if (part->size < TRX_MIN_KERNEL_SIZE) {
part->name = "loader";
i++;
}
part = &trx_parts[i];
part->name = "kernel";
i++;
part = &trx_parts[i];
part->name = "rootfs";
err = mtd_device_register(mtd, trx_parts, trx_nr_parts);
if (err) {
printk(KERN_ALERT PFX "adding TRX partitions failed\n");
return;
}
mtd->refresh_device = trxsplit_refresh_partitions;
}
static int trxsplit_refresh_partitions(struct mtd_info *mtd)
{
printk(KERN_INFO PFX "refreshing TRX partitions in '%s' (%d,%d)\n",
mtd->name, MTD_BLOCK_MAJOR, mtd->index);
/* remove old partitions */
mtd_device_unregister(mtd);
trxsplit_findtrx(mtd);
if (!trx_mtd)
goto err;
trxsplit_create_partitions(trx_mtd);
return 1;
err:
return 0;
}
static void __init trxsplit_add_mtd(struct mtd_info *mtd)
{
if (mtd->type != MTD_NORFLASH) {
printk(KERN_INFO PFX "'%s' is not a NOR flash, skipped\n",
mtd->name);
return;
}
if (!trx_mtd)
trxsplit_findtrx(mtd);
}
static void __init trxsplit_remove_mtd(struct mtd_info *mtd)
{
/* nothing to do */
}
static struct mtd_notifier trxsplit_notifier __initdata = {
.add = trxsplit_add_mtd,
.remove = trxsplit_remove_mtd,
};
static void __init trxsplit_scan(void)
{
register_mtd_user(&trxsplit_notifier);
unregister_mtd_user(&trxsplit_notifier);
}
static int __init trxsplit_init(void)
{
trxsplit_scan();
if (trx_mtd) {
printk(KERN_INFO PFX "creating TRX partitions in '%s' "
"(%d,%d)\n", trx_mtd->name, MTD_BLOCK_MAJOR,
trx_mtd->index);
trxsplit_create_partitions(trx_mtd);
}
return 0;
}
late_initcall(trxsplit_init);
|
