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check crc of embedded compressed firmware after expansion
[rsbs2] / rsb-lz.c
CommitLineData
90836933 1#include <stdio.h>
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2#include <stdlib.h>
3#include <strings.h>
4#include <string.h>
e433bc03 5#include <unistd.h>
14ff7444 6#include <errno.h>
af1fed3a 7#include "rsb-crc.h"
90836933 8#include "rsb-lz.h"
e8563c43 9#include "filesystem.h"
90836933 10
2363a0d6 11void err_exit(const char *fname)
14ff7444 12{
e4a6d4c3 13 fprintf(stderr,"%s: error extracting...\n", fname);
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14 exit(1);
15}
16
7e4dc833 17struct data_in_s {
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18 unsigned char *start;
19 unsigned char *stop;
20 unsigned char bitpos;
21 unsigned char byte;
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22};
23
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24struct data_out_s {
25 unsigned char *pos;
26 unsigned char *end;
27};
28
6b2c0993 29unsigned char get_next_in_byte(struct data_in_s *data_in)
af1fed3a 30{
6b2c0993 31 unsigned char byte;
5e9ad31f 32
6b2c0993 33 if (data_in->stop < data_in->start)
2363a0d6 34 err_exit(__func__);
5e9ad31f 35
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36 byte = *(data_in->start);
37 data_in->start++;
5e9ad31f 38
6b2c0993 39 return byte;
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40}
41
6d8c2f71 42unsigned char get_next_bit(struct data_in_s *data_in)
e4a6d4c3 43{
6d8c2f71 44 unsigned char bitval;
e4a6d4c3 45
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46 if (data_in->bitpos == 0x80) {
47 data_in->byte = get_next_in_byte(data_in);
e4a6d4c3 48 }
6b2c0993 49
6d8c2f71 50 bitval = data_in->bitpos & data_in->byte;
6b2c0993 51
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52 data_in->bitpos >>= 1;
53 if (data_in->bitpos == 0) {
54 data_in->bitpos = 0x80;
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55 }
56
6d8c2f71 57 if (bitval == 0)
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58 return 0;
59
60 return 1;
61}
62
6d8c2f71 63unsigned int get_next_bits(struct data_in_s *data_in, unsigned int bits)
3772880c 64{
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65 unsigned int bit;
66 unsigned int next_bits;
3772880c 67
6d8c2f71 68 bit = 1 << (bits - 1);
3772880c 69
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70 next_bits = 0;
71 while (bit != 0) {
72 if (data_in->bitpos == 0x80) {
73 data_in->byte = get_next_in_byte(data_in);
3772880c 74 }
3772880c 75
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76 if ((data_in->bitpos & data_in->byte) != 0)
77 next_bits = next_bits | bit;
78
79 bit = bit >> 1;
3772880c 80
6d8c2f71 81 data_in->bitpos >>= 1;
3772880c 82
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83 if(data_in->bitpos == 0) {
84 data_in->bitpos = 0x80;
3772880c 85 }
90c723bb 86 }
3772880c 87
6d8c2f71 88 return next_bits;
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89}
90
b0ddcea9 91void write_byte(unsigned char byte, struct data_out_s *data_out)
af1fed3a 92{
b0ddcea9 93 if (data_out->pos > data_out->end) {
2363a0d6 94 err_exit(__func__);
e4a6d4c3 95 }
9897bfc3 96
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97 *(data_out->pos) = byte;
98 data_out->pos++;
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99}
100
56a9a862 101void lz_expand(struct data_in_s *data_in, struct data_out_s *data_out)
af1fed3a 102{
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103 unsigned int pos;
104 unsigned int offset;
105 unsigned int i;
106 unsigned char byte;
107 unsigned int num;
108 unsigned char buf[1024];
af1fed3a 109
56a9a862 110 pos = 1;
af1fed3a 111
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112 while (1) {
113 while (1) {
56a9a862 114 if (get_next_bit(data_in) == 0)
05c92ac4 115 break;
af1fed3a 116
56a9a862 117 byte = get_next_bits(data_in, 8);
af1fed3a 118
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119 write_byte(byte, data_out);
120 buf[pos] = byte;
121 pos = (pos + 1) & 0x3ff;
90c723bb 122 }
af1fed3a 123
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124 offset = get_next_bits(data_in, 0x0a);
125 if(offset == 0)
05c92ac4 126 return;
af1fed3a 127
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128 num = get_next_bits(data_in, 0x04) + 1;
129 for (i = 0; i <= num; i++) {
130 byte = buf[(offset + i) & 0x3ff];
131 write_byte(byte, data_out);
132 buf[pos] = byte;
133 pos = (pos + 1) & 0x3ff;
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134 }
135 }
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136}
137
6b2c0993 138/* Checksum is only used for the compressed firmware in 'firmware' */
a7420422 139unsigned int crc_check(unsigned char *buf, unsigned int len, unsigned int magic)
af1fed3a 140{
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141 unsigned int file_crc;
142 unsigned int my_len;
143 unsigned int crc;
144 unsigned int my_magic;
af1fed3a 145
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146 my_len = *((unsigned int*)(buf + 0x20));
147 my_magic = *((unsigned int*)(buf + 0x24));
af1fed3a 148
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149 if (my_magic != magic) {
150 printf("\nmagic: 0x%08x <-> 0x%08x\n", my_magic, magic);
af1fed3a 151 return 2;
a7420422 152 }
af1fed3a 153
a7420422 154 if (len < my_len)
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155 return 3;
156
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157 crc = ~rsb_crc(~0x00, buf, len);
158 file_crc = *((unsigned int*)(buf + len));
af1fed3a 159
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160 if (file_crc != crc) {
161 printf("\nChecksums: 0x%08x <-> 0x%08x!\n", crc, file_crc);
162 return 4;
163 }
af1fed3a 164
a7420422 165 return 0;
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166}
167
a7420422 168void extract_lz_file(unsigned char *inbuf, unsigned char *name, unsigned char check_crc)
14ff7444 169{
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170 unsigned int len;
171 unsigned char *outbuf;
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172 struct data_in_s data_in;
173 struct data_out_s data_out;
14ff7444 174
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175 if (*((unsigned int*)inbuf) != LZ_MAGIC)
176 err_exit(__func__);
e4a6d4c3 177
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178 len = *((unsigned int*)(inbuf + 4));
179 printf(", length: %d", len);
14ff7444 180
2363a0d6 181 if ((outbuf = malloc(len)) == NULL) {
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182 perror("malloc");
183 exit(1);
184 }
e433bc03 185
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186 bzero(outbuf, len);
187
188 data_in.start = inbuf + 8;
189 data_in.stop = inbuf + len;
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190 data_in.byte = 0x00;
191 data_in.bitpos = 0x80;
14ff7444 192
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193 data_out.pos = outbuf;
194 data_out.end = outbuf + len;
14ff7444 195
7e4dc833 196 lz_expand(&data_in, &data_out);
14ff7444 197
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198 if (check_crc) {
199 unsigned int crclen;
200 int ret;
af1fed3a 201
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202 crclen = *((unsigned int*)(outbuf + 0x20));
203
204 if ((ret = crc_check(outbuf, crclen, 0x46335053)) != 0) {
205 printf("crc_check return: %d\n", ret);
206 err_exit(__func__);
207 }
e433bc03 208 }
af1fed3a 209
2363a0d6 210 write_file((char*)name, outbuf, len);
e433bc03 211
2363a0d6 212 free(outbuf);
14ff7444 213}
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