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
|
/* $Id$ */
/*
* Copyright (c) 2005 Chris Kuethe <chris.kuethe@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include "gpsd_config.h"
#include "gpsd.h"
/*
* See srec(5) for a description of this format.
* We read and write 4-byte addresses.
* S0: Comments
* S3: Memory Loadable Data, 4byte address
* S5: Count of S1, S2 and S3 Records
* S7: starting execution address interpreted as a 4-byte address
*/
#define MAX_BYTES_PER_RECORD 16
/*
* bin2srec: turn a chunk of binary into an S-record
* offset: used to specify load address
* num: up to MAX_BYTES_PER_RECORD bytes can be encoded at one time
* bytes are read from bbuf and a ready-to-go srecord is placed in sbuf
*/
int
bin2srec(unsigned int type, unsigned int offset, unsigned int num, unsigned char *bbuf, unsigned char *sbuf){
unsigned char abuf[MAX_BYTES_PER_RECORD*2 + 2], sum;
size_t len;
if ((num < 1) || (num > MAX_BYTES_PER_RECORD))
return -1;
len = (size_t)(4 + num + 1);
memset(abuf, 0, sizeof(abuf));
hexdump((size_t)num, bbuf, abuf);
sum = sr_sum((unsigned int)len, offset, bbuf);
(void)snprintf((char *)sbuf, MAX_BYTES_PER_RECORD*2 + 17,
"S%u%02X%08X%s%02X\r\n",
type, (unsigned)len, offset, (char *)abuf, (unsigned)sum);
return 0;
}
int
srec_hdr(unsigned int num, unsigned char *bbuf, unsigned char *sbuf){
return bin2srec(0, 0, num, bbuf, sbuf);
}
int
srec_fin(unsigned int num, unsigned char *sbuf){
unsigned char bbuf[4], sum;
memset(bbuf, 0, 4);
bbuf[0] = (unsigned char)(num & 0xff);
bbuf[1] = (unsigned char)((num >> 8) & 0xff);
sum = sr_sum(3, 0, bbuf);
(void)snprintf((char *)sbuf, 13, "S503%04X%02X\r\n", num, (unsigned)sum);
return 0;
}
void
hexdump(size_t len, unsigned char *bbuf, unsigned char *abuf){
size_t i;
memset(abuf, 0, MAX_BYTES_PER_RECORD*2 + 2);
if (len > MAX_BYTES_PER_RECORD*2)
len = MAX_BYTES_PER_RECORD*2;
for(i = 0; i < len; i++){
abuf[i*2] = hc((bbuf[i] &0xf0) >> 4);
abuf[i*2+1] = hc(bbuf[i] &0x0f);
}
}
/*@ -type @*/
unsigned char
hc(unsigned char x){
switch(x){
case 15:
case 14:
case 13:
case 12:
case 11:
case 10:
return ('A' + x - 10);
case 9:
case 8:
case 7:
case 6:
case 5:
case 4:
case 3:
case 2:
case 1:
case 0:
return ('0' + x);
default:
return '0';
}
}
/*@ -type @*/
unsigned char
sr_sum(unsigned int count, unsigned int addr, unsigned char *bbuf){
int i, j;
unsigned char k, sum = 0;
sum = (count & 0xff);
sum += ((addr & 0x000000ff));
sum += ((addr & 0x0000ff00) >> 8);
sum += ((addr & 0x00ff0000) >> 16);
sum += ((addr & 0xff000000) >> 24);
j = count - 5;
for(i = 0; i < j; i++){
k = bbuf[i];
sum += k;
}
return ~sum;
}
|
