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
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
|
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/* #define DEBUG 1 */
/*
* Fw Header Layout for Netgear / Sercomm devices
* */
static const char *magic = "sErCoMm"; /* 7 */
/* 7-11: version control/download control ? */
unsigned char version[4] = {0x00, 0x01, 0x00, 0x00};
char *hwID = ""; /* 11-43 , ASCII/HEX */
char *hwVer = ""; /* 44-57 , ASCII/HEX */
char *swVer = ""; /* 58-62 , ASCII/HEX */
/* magic again. */
#define HEADER_SIZE 71
/* null bytes until 511 */
u_int32_t checksum = 0xFF; /* checksum */
/* 512 onwards -> ZIP containing rootfs with the same Header */
/* appended on rootfs for the Header. */
const int footer_size = 128;
struct file_info {
char *file_name; /* name of the file */
char *file_data; /* data of the file in memory */
u_int32_t file_size; /* length of the file */
};
u_int8_t getCheckSum(char *data, int len)
{
int32_t previous = 0;
u_int32_t new = 0;
for (u_int32_t i = 0; i < len; i++) {
new = (data[i] + previous) % 256;
previous = new | previous & -256;
}
return (u_int8_t) new;
}
void *bufferFile(struct file_info *finfo, int dontload)
{
int fs = 0;
FILE *f = NULL;
#ifdef DEBUG
printf("Opening file: %s\n", finfo->file_name);
#endif
f = fopen(finfo->file_name, "rb");
if (f == NULL) {
perror("Error");
exit(1);
}
fseek(f, 0L, SEEK_END);
fs = ftell(f);
rewind(f);
#ifdef DEBUG
printf("Filesize: %i .\n", fs);
#endif
finfo->file_size = fs;
if (dontload) {
return 0;
}
char *data = malloc(fs);
finfo->file_data = data;
int read = fread(data, fs, 1, f);
if (read != 1) {
printf("Error reading file %s.", finfo->file_name);
exit(1);
}
#ifdef DEBUG
printf("File: read successfully %i bytes.\n", read*fs);
#endif
fclose(f);
}
void *writeFile(struct file_info *finfo)
{
#ifdef DEBUG
printf("Writing file: %s.\n", finfo->file_name);
#endif
FILE *fout = fopen(finfo->file_name, "w");
if (!fwrite(finfo->file_data, finfo->file_size, 1, fout)) {
printf("Wanted to write, but something went wrong.\n");
fclose(fout);
exit(1);
}
fclose(fout);
}
void *rmFile(struct file_info *finfo)
{
remove(finfo->file_name);
free(finfo->file_data);
finfo->file_size = 0;
}
void *usage(char *argv[])
{
printf("Usage: %s <sysupgradefile> <kernel_offset> <HWID> <HWVER> <SWID>\n"
"All are positional arguments ... \n"
" sysupgradefile: File with the kernel uimage at 0\n"
" kernel_offset: Offset in Hex where the kernel is located\n"
" HWID: Hardware ID, ASCII\n"
" HWVER: Hardware Version, ASCII\n"
" SWID: Software Version, Hex\n"
" \n"
" ", argv[0]);
}
int main(int argc, char *argv[])
{
printf("Building fw image for sercomm devices.\n");
if (argc == 2) {
struct file_info myfile = {argv[1], 0, 0};
bufferFile(&myfile, 0);
char chksum = getCheckSum(myfile.file_data, myfile.file_size);
printf("Checksum for File: %X.\n", chksum);
return;
}
if (argc != 6) {
usage(argv);
return 1;
}
/* Args */
struct file_info sysupgrade = {argv[1], 0, 0};
bufferFile(&sysupgrade, 0);
int kernel_offset = 0x90000; /* offset for the kernel inside the rootfs, default val */
sscanf(argv[2], "%X", &kernel_offset);
#ifdef DEBUG
printf("Kernel_offset: at %X/%i bytes.\n", kernel_offset, kernel_offset);
#endif
char *hwID = argv[3];
char *hwVer = argv[4];
u_int32_t swVer = 0;
sscanf(argv[5],"%4X",&swVer);
swVer = bswap_32(swVer);
char *rootfsname = malloc(2*strlen(sysupgrade.file_name) + 8);
sprintf(rootfsname, "%s.rootfs", sysupgrade.file_name);
char *zipfsname = malloc(2*strlen(rootfsname) + 5);
sprintf(zipfsname, "%s.zip", rootfsname);
/* / Args */
#ifdef DEBUG
printf("Building header: %s %s %2X %s.\n", hwID , hwVer, swVer, magic);
#endif
/* Construct the firmware header/magic */
struct file_info header = {0, 0, 0};
header.file_size = HEADER_SIZE;
header.file_data = malloc(HEADER_SIZE);
bzero(header.file_data, header.file_size);
char *tg = header.file_data;
strcpy(tg, magic);
memcpy(tg+7, version, 4*sizeof(char));
strcpy(tg+11, hwID);
strcpy(tg+45, hwVer);
memcpy(tg+55, &swVer,sizeof(u_int32_t));
strcpy(tg+63, magic);
#ifdef DEBUG
printf("Header done, now creating rootfs.");
#endif
/* Construct a rootfs */
struct file_info rootfs = {0, 0, 0};
rootfs.file_size = sysupgrade.file_size + kernel_offset + footer_size;
rootfs.file_data = malloc(rootfs.file_size);
bzero(rootfs.file_data, rootfs.file_size);
rootfs.file_name = rootfsname;
/* copy Owrt image to Kernel location */
memcpy(rootfs.file_data+kernel_offset, sysupgrade.file_data, sysupgrade.file_size);
/* 22 added to get away from sysup image, no other reason.
* updater searches for magic anyway */
tg = rootfs.file_data + kernel_offset + sysupgrade.file_size+22;
memcpy(tg, header.file_data, header.file_size);
writeFile(&rootfs);
#ifdef DEBUG
printf("Preparing to zip.\n");
#endif
/* now that we got the rootfs, repeat the whole thing again(sorta):
* 1. zip the rootfs */
char *zipper = malloc(5 + 2*strlen(rootfs.file_name) + 4);
sprintf(zipper, "%s %s %s", "zip ", zipfsname, rootfs.file_name);
int ret = system(zipper);
/* clear rootfs file */
rmFile(&rootfs);
/* and load zipped fs */
struct file_info zippedfs = {zipfsname, 0, 0};
bufferFile(&zippedfs, 0);
#ifdef DEBUG
printf("Creating Image.\n");
#endif
/* 2. create new file 512+rootfs size */
struct file_info image = {argv[1], 0, 0};
image.file_data = malloc(zippedfs.file_size + 512);
image.file_size = zippedfs.file_size + 512;
/* 3. copy zipfile at loc 512 */
memcpy(image.file_data+512, zippedfs.file_data, zippedfs.file_size);
rmFile(&zippedfs);
/* 4. add header to file */
memcpy(image.file_data, header.file_data, header.file_size);
/* 5. do a checksum run, and compute checksum */
char chksum = getCheckSum(image.file_data, image.file_size);
#ifdef DEBUG
printf("Checksum for Image: %X.\n", chksum);
#endif
/* 6. write the checksum invert into byte 511 to bring it to 0 */
chksum = (chksum ^ 0xFF) + 1;
memcpy(image.file_data+511, &chksum, 1);
chksum = getCheckSum(image.file_data, image.file_size);
#ifdef DEBUG
printf("Checksum for after fix: %X.\n", chksum);
#endif
/* 7. pray that the updater will accept the file */
writeFile(&image);
return 0;
}
|
