int
gdb_rx_begin(void)
{
int c, cksum;
gdb_rxp = NULL;
do {
/*
* Wait for the start character, ignore all others.
* XXX needs a timeout.
*/
while ((c = gdb_getc()) != '$')
;
/* Read until a # or end of buffer is found. */
cksum = 0;
gdb_rxsz = 0;
while (gdb_rxsz < sizeof(gdb_rxbuf) - 1) {
c = gdb_getc();
if (c == '#')
break;
gdb_rxbuf[gdb_rxsz++] = c;
cksum += c;
}
gdb_rxbuf[gdb_rxsz] = 0;
cksum &= 0xff;
/* Bail out on a buffer overflow. */
if (c != '#') {
gdb_cur->gdb_putc('-');
return (ENOSPC);
}
c = gdb_getc();
cksum -= (C2N(c) << 4) & 0xf0;
c = gdb_getc();
cksum -= C2N(c) & 0x0f;
gdb_cur->gdb_putc((cksum == 0) ? '+' : '-');
if (cksum != 0)
printf("GDB: packet `%s' has invalid checksum\n",
gdb_rxbuf);
} while (cksum != 0);
gdb_rxp = gdb_rxbuf;
return (0);
}
static int run(struct gdb_data *data, char *buf)
{
printc("Running\n");
if (run_set_pc(data, buf) < 0 ||
device_ctl(DEVICE_CTL_RUN) < 0)
return gdb_send(data, "E00");
for (;;) {
device_status_t status = device_poll();
if (status == DEVICE_STATUS_ERROR)
return gdb_send(data, "E00");
if (status == DEVICE_STATUS_HALTED) {
printc("Target halted\n");
goto out;
}
if (status == DEVICE_STATUS_INTR)
goto out;
while (gdb_peek(data, 0)) {
int c = gdb_getc(data);
if (c < 0)
return -1;
if (c == 3) {
printc("Interrupted by gdb\n");
goto out;
}
}
}
out:
if (device_ctl(DEVICE_CTL_HALT) < 0)
return gdb_send(data, "E00");
return run_final_status(data);
}
int
gdb_tx_end(void)
{
const char *p;
int runlen;
unsigned char c, cksum;
do {
gdb_cur->gdb_putc('$');
cksum = 0;
p = gdb_txbuf;
while (p < gdb_txp) {
/* Send a character and start run-length encoding. */
c = *p++;
gdb_cur->gdb_putc(c);
cksum += c;
runlen = 0;
/* Determine run-length and update checksum. */
while (p < gdb_txp && *p == c) {
runlen++;
p++;
}
/* Emit the run-length encoded string. */
while (runlen >= 97) {
gdb_cur->gdb_putc('*');
cksum += '*';
gdb_cur->gdb_putc(97+29);
cksum += 97+29;
runlen -= 97;
if (runlen > 0) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
}
if (runlen == 1) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
if (runlen == 0)
continue;
/* Don't emit '$', '#', '+' or '-'. */
if (runlen == 7) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
if (runlen == 6 || runlen == 14 || runlen == 16) {
gdb_cur->gdb_putc(c);
cksum += c;
runlen--;
}
gdb_cur->gdb_putc('*');
cksum += '*';
gdb_cur->gdb_putc(runlen+29);
cksum += runlen+29;
}
gdb_cur->gdb_putc('#');
c = cksum >> 4;
gdb_cur->gdb_putc(N2C(c));
c = cksum & 0x0f;
gdb_cur->gdb_putc(N2C(c));
c = gdb_getc();
} while (c != '+');
return (0);
}
