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
|
#include "rsp.h"
/* recv() */
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h> /* memset(), strncmp() */
#include <stdio.h> /* perror(), fprintf(), snprintf(), sscanf() */
#include <stdlib.h> /* malloc(), free() */
#include <unistd.h> /* close() */
#include <errno.h> /* EAGAIN... */
void _rsp_sniff_garbage(struct rsp_state *rsp) {
int recvbytes, rv;
// Sniff garbages before sending command
recvbytes = recv(rsp->sockfd, rsp->response, rsp->data_maxlen, MSG_DONTWAIT);
if ( recvbytes < 0 ) {
rv = errno;
if ( rv == EAGAIN || rv == EWOULDBLOCK ) {
/* No garbage found, that's a good news */
} else {
LOG_DEBUG("! <-(error %i)\n", rv);
}
recvbytes=0;
}
rsp->response[recvbytes] = '\0';
if ( recvbytes > 0 ) {
LOG_DEBUG("! <-'%s'\n",rsp->response);
}
}
int rsp_recv_full(struct rsp_state *rsp) {
int rv, error=0, complete=0, full=0, sentbytes;
ssize_t bufoldpos=0, bufpos=0;
char *bom=NULL, *eom=NULL, *ptr;
unsigned char c, cack='+';
unsigned int computed_checksum, read_checksum;
do {
rv = recv(rsp->sockfd, rsp->response + bufpos, rsp->data_maxlen - bufpos, 0);
if ( rv < 0 ) {
switch (errno) {
case EAGAIN:
continue;
default:
error=1;
continue;
}
}
if ( rv == 0 ) {
error=1;
continue;
}
bufoldpos = bufpos;
bufpos += rv;
if ( bom == NULL ) {
bom = memchr(rsp->response + bufoldpos, '$', bufpos - bufoldpos);
}
if ( bom != NULL && eom == NULL ) {
eom = memchr(bom, '#', bufpos - (bom - rsp->response) );
}
complete = bom && eom && (eom+2) <= (rsp->response + bufpos); // 2 char checksum after EOM
full = (bufpos >= rsp->data_maxlen);
} while (!error && !complete && !full);
if (error) return 1;
if (full) return 2;
rsp->response[bufpos]='\0';
c=eom[3];
eom[3]='\0';
LOG_DEBUG(" <- '%s'\n", rsp->response);
if ( (eom+3) < (rsp->response + bufpos - 1)) {
eom[3]=c;
LOG_DEBUG("? <- '%s'\n", eom+3);
}
rsp->response_len = eom - bom - 1;
rsp->response_bom = bom;
rsp->response_eom = eom;
computed_checksum=0;
for (ptr = bom+1; ptr < eom; ptr++) {
computed_checksum = (computed_checksum + ((unsigned char)*ptr) ) % 256;
}
rv = sscanf(eom + 1, "%02x", &read_checksum);
if ( rv != 1 || computed_checksum != read_checksum) return 3;
rsp->replied = 1;
if (rsp->noackmode !=1) {
sentbytes = send(rsp->sockfd, &cack, 1, 0);
if ( sentbytes < 1 ) return 4;
LOG_DEBUG("-> '+'\n");
}
return 0;
}
int rsp_init(int sockfd, int data_maxlen, struct rsp_state *rsp) {
memset(rsp,0,sizeof(struct rsp_state));
rsp->sockfd = sockfd;
rsp->data_maxlen = data_maxlen;
rsp->command = malloc(data_maxlen+1);
if ( rsp->command == NULL ) return 1;
rsp->response = malloc(data_maxlen+1);
if ( rsp->response == NULL ) return 1;
rsp->decoded = malloc(data_maxlen+1);
if ( rsp->decoded == NULL ) return 1;
/*
rsp_query(rsp, "QStartNoAckMode");
if ( rsp_check_and_clear(rsp, "OK") == 0 ) rsp->noackmode=1;
*/
return 0;
}
void rsp_quit(struct rsp_state *rsp) {
//rsp_query(rsp, "k");
if ( rsp->command != NULL ) free(rsp->command);
if ( rsp->response != NULL ) free(rsp->response);
if ( rsp->decoded != NULL ) free(rsp->decoded);
close(rsp->sockfd);
memset(rsp,0,sizeof(struct rsp_state));
}
void rsp_send_break(struct rsp_state *rsp) {
int sentbytes;
char cbreak=3;
rsp->replied = 0;
rsp->response_len = 0;
//_rsp_sniff_garbage(rsp);
sentbytes = send(rsp->sockfd, &cbreak, 1, 0);
if ( sentbytes < 1 ) return;
LOG_DEBUG("-> '^C'\n");
rsp_recv_full(rsp);
}
void rsp_query(struct rsp_state *rsp, char command[]) {
int sentbytes;
unsigned int checksum, i;
unsigned char c;
rsp->replied = 0;
rsp->response_len = 0;
i=0; checksum=0;
while ( (c=command[i++]) != '\0' ) {
checksum = (checksum + c ) % 256;
}
rsp->command_len = snprintf(rsp->command, rsp->data_maxlen, "$%s#%02hhx", command, checksum);
if (rsp->command_len < 5) return;
//_rsp_sniff_garbage(rsp);
sentbytes = send(rsp->sockfd, rsp->command, rsp->command_len, 0);
if ( sentbytes < rsp->command_len ) return;
LOG_DEBUG("-> '%s'\n", rsp->command);
rsp_recv_full(rsp);
}
int rsp_check_and_clear(struct rsp_state *rsp, char expected_response[]) {
int expected_responselen = strlen(expected_response);
if ( rsp->replied != 1 ) return 1;
rsp->replied = 0;
if ( rsp->response_len < expected_responselen ) return 2;
if ( strncmp(rsp->response_bom + 1, expected_response, expected_responselen) != 0 ) return 3;
return 0;
}
int rsp_decode(struct rsp_state *rsp) {
/*
Response data can be run-length encoded to save space. Run-length encoding replaces runs of identical characters with one instance of the repeated character, followed by a ‘*’ and a repeat count. The repeat count is itself sent encoded, to avoid binary characters in data: a value of n is sent as n+29. For a repeat count greater or equal to 3, this produces a printable ascii character, e.g. a space (ascii code 32) for a repeat count of 3. (This is because run-length encoding starts to win for counts 3 or more.) Thus, for example, ‘0* ’ is a run-length encoding of “0000”: the space character after ‘*’ means repeat the leading 0 32 - 29 = 3 more times.
The printable characters ‘#’ and ‘$’ or with a numeric value greater than 126 must not be used. Runs of six repeats (‘#’) or seven repeats (‘$’) can be expanded using a repeat count of only five (‘"’). For example, ‘00000000’ can be encoded as ‘0*"00’.
*/
char src, *srcptr, *dstptr;
int repe, max;
if ( rsp->replied != 1 ) return -1;
dstptr = rsp->decoded;
for ( srcptr = rsp->response_bom+1; srcptr < rsp->response_eom; srcptr++ ) {
// FIXME : implemnt RLE decoding
src = *srcptr;
switch (src) {
case '*':
srcptr++;
repe=(*srcptr)-29;
if (repe < 2 ) return -1;
max = rsp->decoded + rsp->data_maxlen - 1 - dstptr;
if ( repe > max ) { repe = max; }
memset(dstptr, *(srcptr-2), repe);
dstptr += repe;
break;
default:
*(dstptr++) = *srcptr;
break;
}
}
*dstptr='\0';
return dstptr - rsp->decoded;
}
int rsp_poke(struct rsp_state *rsp, unsigned int poke_addr, unsigned int poke_value) {
char command[16];
printf("DEBUG : rsp_poke()\n");
if ( snprintf(command, 15, "M %4x,2:%2x", poke_addr & 0xffff, poke_value & 0xff) < 11 ) return 1;
printf("DEBUG : command == '%s'\n", command);
rsp_query(rsp, command); // Send the poke command to GDB stub
printf("DEBUG : response == '%s'\n", rsp->response);
if ( rsp_check_and_clear(rsp, "OK") != 0 ) return 2;
return 0;
}
|
