mspdebug/gdb.c

739 lines
15 KiB
C

/* MSPDebug - debugging tool for MSP430 MCUs
* Copyright (C) 2009, 2010 Daniel Beer
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <ctype.h>
#include <stdarg.h>
#include <stdint.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "device.h"
#include "util.h"
#include "opdb.h"
#include "gdb.h"
#include "output.h"
#include "reader.h"
#include "expr.h"
#define MAX_MEM_XFER 8192
/************************************************************************
* GDB IO routines
*/
struct gdb_data {
int sock;
int error;
char xbuf[1024];
int head;
int tail;
char outbuf[MAX_MEM_XFER * 2 + 64];
int outlen;
};
static void gdb_printf(struct gdb_data *data, const char *fmt, ...)
{
va_list ap;
int len;
va_start(ap, fmt);
len = vsnprintf(data->outbuf + data->outlen,
sizeof(data->outbuf) - data->outlen,
fmt, ap);
va_end(ap);
data->outlen += len;
}
static int gdb_read(struct gdb_data *data, int blocking)
{
fd_set r;
int len;
struct timeval to = {
.tv_sec = 0,
.tv_usec = 0
};
FD_ZERO(&r);
FD_SET(data->sock, &r);
if (select(data->sock + 1, &r, NULL, NULL,
blocking ? NULL : &to) < 0) {
pr_error("gdb: select");
return -1;
}
if (!FD_ISSET(data->sock, &r))
return 0;
len = recv(data->sock, data->xbuf, sizeof(data->xbuf), 0);
if (len < 0) {
data->error = errno;
pr_error("gdb: recv");
return -1;
}
if (!len) {
printc("Connection closed\n");
return -1;
}
data->head = 0;
data->tail = len;
return len;
}
static int gdb_peek(struct gdb_data *data)
{
if (data->head == data->tail && gdb_read(data, 0) < 0)
return -1;
return data->head != data->tail;
}
static int gdb_getc(struct gdb_data *data)
{
int c;
/* If the buffer is empty, receive some more data */
if (data->head == data->tail && gdb_read(data, 1) < 0)
return -1;
c = data->xbuf[data->head];
data->head++;
return c;
}
static int gdb_flush(struct gdb_data *data)
{
if (send(data->sock, data->outbuf, data->outlen, 0) < 0) {
data->error = errno;
pr_error("gdb: flush");
return -1;
}
data->outlen = 0;
return 0;
}
static int gdb_flush_ack(struct gdb_data *data)
{
int c;
do {
data->outbuf[data->outlen] = 0;
#ifdef DEBUG_GDB
printc("-> %s\n", data->outbuf);
#endif
if (send(data->sock, data->outbuf, data->outlen, 0) < 0) {
data->error = errno;
pr_error("gdb: flush_ack");
return -1;
}
c = gdb_getc(data);
if (c < 0)
return -1;
} while (c != '+');
data->outlen = 0;
return 0;
}
static void gdb_packet_start(struct gdb_data *data)
{
gdb_printf(data, "$");
}
static void gdb_packet_end(struct gdb_data *data)
{
int i;
int c = 0;
for (i = 1; i < data->outlen; i++)
c = (c + data->outbuf[i]) & 0xff;
gdb_printf(data, "#%02x", c);
}
static int hexval(int c)
{
if (isdigit(c))
return c - '0';
if (isupper(c))
return c - 'A' + 10;
if (islower(c))
return c - 'a' + 10;
return 0;
}
static int gdb_send(struct gdb_data *data, const char *msg)
{
gdb_packet_start(data);
gdb_printf(data, "%s", msg);
gdb_packet_end(data);
return gdb_flush_ack(data);
}
/************************************************************************
* GDB server
*/
static int read_registers(struct gdb_data *data)
{
address_t regs[DEVICE_NUM_REGS];
int i;
printc("Reading registers\n");
if (device_getregs(regs) < 0)
return gdb_send(data, "E00");
gdb_packet_start(data);
for (i = 0; i < DEVICE_NUM_REGS; i++)
gdb_printf(data, "%02x%02x",
regs[i] & 0xff,
(regs[i] >> 8) & 0xff);
gdb_packet_end(data);
return gdb_flush_ack(data);
}
struct monitor_buf {
char buf[MAX_MEM_XFER];
int len;
int trunc;
};
static void monitor_capture(void *user_data, const char *text)
{
struct monitor_buf *mb = (struct monitor_buf *)user_data;
int len = strlen(text);
if (mb->trunc)
return;
if (mb->len + len + 64 > sizeof(mb->buf)) {
text = "...<truncated>";
len = strlen(text);
mb->trunc = 1;
}
memcpy(mb->buf + mb->len, text, len);
mb->len += len;
mb->buf[mb->len++] = '\n';
}
static int monitor_command(struct gdb_data *data, char *buf)
{
char cmd[128];
int len = 0;
int i;
struct monitor_buf mbuf;
while (len + 1 < sizeof(cmd) && *buf && buf[1]) {
if (len + 1 >= sizeof(cmd))
break;
cmd[len++] = (hexval(buf[0]) << 4) | hexval(buf[1]);
buf += 2;
}
cmd[len] = 0;
printc("Monitor command received: %s\n", cmd);
mbuf.len = 0;
mbuf.trunc = 0;
capture_start(monitor_capture, &mbuf);
process_command(cmd);
capture_end();
if (!mbuf.len)
return gdb_send(data, "OK");
gdb_packet_start(data);
for (i = 0; i < mbuf.len; i++)
gdb_printf(data, "%02x", mbuf.buf[i]);
gdb_packet_end(data);
return gdb_flush_ack(data);
}
static int write_registers(struct gdb_data *data, char *buf)
{
address_t regs[DEVICE_NUM_REGS];
int i;
if (strlen(buf) < DEVICE_NUM_REGS * 4)
return gdb_send(data, "E00");
printc("Writing registers\n");
for (i = 0; i < DEVICE_NUM_REGS; i++) {
regs[i] = (hexval(buf[2]) << 12) |
(hexval(buf[3]) << 8) |
(hexval(buf[0]) << 4) |
hexval(buf[1]);
buf += 4;
}
if (device_setregs(regs) < 0)
return gdb_send(data, "E00");
return gdb_send(data, "OK");
}
static int read_memory(struct gdb_data *data, char *text)
{
char *length_text = strchr(text, ',');
address_t length, addr;
uint8_t buf[MAX_MEM_XFER];
int i;
if (!length_text) {
printc_err("gdb: malformed memory read request\n");
return gdb_send(data, "E00");
}
*(length_text++) = 0;
length = strtoul(length_text, NULL, 16);
addr = strtoul(text, NULL, 16);
if (length > sizeof(buf))
length = sizeof(buf);
printc("Reading %4d bytes from 0x%04x\n", length, addr);
if (device_readmem(addr, buf, length) < 0)
return gdb_send(data, "E00");
gdb_packet_start(data);
for (i = 0; i < length; i++)
gdb_printf(data, "%02x", buf[i]);
gdb_packet_end(data);
return gdb_flush_ack(data);
}
static int write_memory(struct gdb_data *data, char *text)
{
char *data_text = strchr(text, ':');
char *length_text = strchr(text, ',');
address_t length, addr;
uint8_t buf[MAX_MEM_XFER];
int buflen = 0;
if (!(data_text && length_text)) {
printc_err("gdb: malformed memory write request\n");
return gdb_send(data, "E00");
}
*(data_text++) = 0;
*(length_text++) = 0;
length = strtoul(length_text, NULL, 16);
addr = strtoul(text, NULL, 16);
while (buflen < sizeof(buf) && *data_text && data_text[1]) {
buf[buflen++] = (hexval(data_text[0]) << 4) |
hexval(data_text[1]);
data_text += 2;
}
if (buflen != length) {
printc_err("gdb: length mismatch\n");
return gdb_send(data, "E00");
}
printc("Writing %4d bytes to 0x%04x\n", length, addr);
if (device_writemem(addr, buf, buflen) < 0)
return gdb_send(data, "E00");
return gdb_send(data, "OK");
}
static int run_set_pc(struct gdb_data *data, char *buf)
{
address_t regs[DEVICE_NUM_REGS];
if (!*buf)
return 0;
if (device_getregs(regs) < 0)
return -1;
regs[0] = strtoul(buf, NULL, 16);
return device_setregs(regs);
}
static int run_final_status(struct gdb_data *data)
{
address_t regs[DEVICE_NUM_REGS];
int i;
if (device_getregs(regs) < 0)
return gdb_send(data, "E00");
gdb_packet_start(data);
gdb_printf(data, "T05");
for (i = 0; i < 16; i++) {
address_t value = regs[i];
int j;
/* NOTE: this only gives GDB the lower 16 bits of each
* register. It complains if we give the full data.
*/
gdb_printf(data, "%02x:", i);
for (j = 0; j < 2; j++) {
gdb_printf(data, "%02x", value & 0xff);
value >>= 8;
}
gdb_printf(data, ";");
}
gdb_packet_end(data);
return gdb_flush_ack(data);
}
static int single_step(struct gdb_data *data, char *buf)
{
printc("Single stepping\n");
if (run_set_pc(data, buf) < 0 ||
device_ctl(DEVICE_CTL_STEP) < 0)
gdb_send(data, "E00");
return run_final_status(data);
}
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)) {
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);
}
static int set_breakpoint(struct gdb_data *data, int enable, char *buf)
{
char *parts[2];
int type;
address_t addr;
int i;
/* Break up the arguments */
for (i = 0; i < 2; i++)
parts[i] = strsep(&buf, ",");
/* Make sure there's a type argument */
if (!parts[0]) {
printc_err("gdb: breakpoint requested with no type\n");
return gdb_send(data, "E00");
}
/* We only support breakpoints */
type = atoi(parts[0]);
if (type < 0 || type > 1) {
printc_err("gdb: unsupported breakpoint type: %s\n",
parts[0]);
return gdb_send(data, "");
}
/* There needs to be an address specified */
if (!parts[1]) {
printc_err("gdb: breakpoint address missing\n");
return gdb_send(data, "E00");
}
/* Parse the breakpoint address */
addr = strtoul(parts[1], NULL, 16);
if (enable) {
if (device_setbrk(device_default, -1, 1, addr) < 0) {
printc_err("gdb: can't add breakpoint at "
"0x%04x\n", addr);
return gdb_send(data, "E00");
}
printc("Breakpoint set at 0x%04x\n", addr);
} else {
device_setbrk(device_default, -1, 0, addr);
printc("Breakpoint cleared at 0x%04x\n", addr);
}
return gdb_send(data, "OK");
}
static int gdb_send_supported(struct gdb_data *data)
{
gdb_packet_start(data);
gdb_printf(data, "PacketSize=%x", MAX_MEM_XFER * 2);
gdb_packet_end(data);
return gdb_flush_ack(data);
}
static int process_gdb_command(struct gdb_data *data, char *buf, int len)
{
#ifdef DEBUG_GDB
printc("process_gdb_command: %s\n", buf);
#endif
switch (buf[0]) {
case '?': /* Return target halt reason */
return run_final_status(data);
case 'z':
case 'Z':
return set_breakpoint(data, buf[0] == 'Z', buf + 1);
case 'g': /* Read registers */
return read_registers(data);
case 'G': /* Write registers */
return write_registers(data, buf + 1);
case 'q': /* Query */
if (!strncmp(buf, "qRcmd,", 6))
return monitor_command(data, buf + 6);
if (!strncmp(buf, "qSupported", 10))
return gdb_send_supported(data);
break;
case 'm': /* Read memory */
return read_memory(data, buf + 1);
case 'M': /* Write memory */
return write_memory(data, buf + 1);
case 'c': /* Continue */
return run(data, buf + 1);
case 's': /* Single step */
return single_step(data, buf + 1);
case 'k': /* kill */
return -1;
}
#ifdef DEBUG_GDB
printc("process_gdb_command: unknown command %s\n", buf);
#endif
/* For unknown/unsupported packets, return an empty reply */
return gdb_send(data, "");
}
static void gdb_reader_loop(struct gdb_data *data)
{
for (;;) {
char buf[MAX_MEM_XFER * 2 + 64];
int len = 0;
int cksum_calc = 0;
int cksum_recv = 0;
int c;
/* Wait for packet start */
do {
c = gdb_getc(data);
if (c < 0)
return;
} while (c != '$');
/* Read packet payload */
while (len + 1 < sizeof(buf)) {
c = gdb_getc(data);
if (c < 0)
return;
if (c == '#')
break;
buf[len++] = c;
cksum_calc = (cksum_calc + c) & 0xff;
}
buf[len] = 0;
/* Read packet checksum */
c = gdb_getc(data);
if (c < 0)
return;
cksum_recv = hexval(c);
c = gdb_getc(data);
if (c < 0)
return;
cksum_recv = (cksum_recv << 4) | hexval(c);
#ifdef DEBUG_GDB
printc("<- $%s#%02x\n", buf, cksum_recv);
#endif
if (cksum_recv != cksum_calc) {
printc_err("gdb: bad checksum (calc = 0x%02x, "
"recv = 0x%02x)\n", cksum_calc, cksum_recv);
printc_err("gdb: packet data was: %s\n", buf);
gdb_printf(data, "-");
if (gdb_flush(data) < 0)
return;
continue;
}
/* Send acknowledgement */
gdb_printf(data, "+");
if (gdb_flush(data) < 0)
return;
if (len && process_gdb_command(data, buf, len) < 0)
return;
}
}
static int gdb_server(int port)
{
int sock;
int client;
struct sockaddr_in addr;
socklen_t len;
int arg;
struct gdb_data data;
int i;
sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sock < 0) {
pr_error("gdb: can't create socket");
return -1;
}
arg = 1;
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &arg, sizeof(arg)) < 0)
pr_error("gdb: warning: can't reuse socket address");
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
printc_err("gdb: can't bind to port %d: %s\n",
port, strerror(errno));
close(sock);
return -1;
}
if (listen(sock, 1) < 0) {
pr_error("gdb: can't listen on socket");
close(sock);
return -1;
}
printc("Bound to port %d. Now waiting for connection...\n", port);
len = sizeof(addr);
client = accept(sock, (struct sockaddr *)&addr, &len);
if (client < 0) {
pr_error("gdb: failed to accept connection");
close(sock);
return -1;
}
close(sock);
printc("Client connected from %s:%d\n",
inet_ntoa(addr.sin_addr), htons(addr.sin_port));
data.sock = client;
data.error = 0;
data.head = 0;
data.tail = 0;
data.outlen = 0;
/* Put the hardware breakpoint setting into a known state. */
printc("Clearing all breakpoints...\n");
for (i = 0; i < device_default->max_breakpoints; i++)
device_setbrk(device_default, i, 0, 0);
#ifdef DEBUG_GDB
printc("starting GDB reader loop...\n");
#endif
gdb_reader_loop(&data);
#ifdef DEBUG_GDB
printc("... reader loop returned\n");
#endif
close(client);
return data.error ? -1 : 0;
}
int cmd_gdb(char **arg)
{
char *port_text = get_arg(arg);
address_t port = 2000;
if (port_text && expr_eval(port_text, &port) < 0) {
printc_err("gdb: can't parse port: %s\n", port_text);
return -1;
}
if (port <= 0 || port > 65535) {
printc_err("gdb: invalid port: %d\n", port);
return -1;
}
do {
if (gdb_server(port) < 0)
return -1;
} while (opdb_get_boolean("gdb_loop"));
return 0;
}