commit e7496ed06e21bcda3606b948585fde2d1ce73df0
parent 3a09e1c522eb3ff7dee4d3f77b17c65691d6ebce
Author: Brian Swetland <swetland@frotz.net>
Date: Mon, 22 Jun 2015 23:31:11 -0700
gdb-bridge: improve stop/step/continue integration
- track when gdb thinks we're running (and thus it's stopped) and
aggressively poll the target state (~10ms) to notice when it
stops and send a stop message when that happens
- treat 's' as a silent command, like 'c'
- provide signal_gdb_server() for eventual integration with
the debugger core monitoring service
Diffstat:
| M | tools/gdb-bridge.c | | | 129 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------ |
1 file changed, 100 insertions(+), 29 deletions(-)
diff --git a/tools/gdb-bridge.c b/tools/gdb-bridge.c
@@ -22,6 +22,7 @@
#include <string.h>
#include <errno.h>
#include <signal.h>
+#include <poll.h>
#include <fw/types.h>
#include "rswdp.h"
@@ -34,20 +35,22 @@
// set debug arch 1 architecture tracing
// maint print registers-remote check on register map
-#define MAXPKT 8192
+#define MAXPKT 8192
-#define S_IDLE 0
-#define S_RECV 1
-#define S_CHK1 2
-#define S_CHK2 3
+#define S_IDLE 0
+#define S_RECV 1
+#define S_CHK1 2
+#define S_CHK2 3
-#define F_ACK 1
-#define F_TRACE 2
+#define F_ACK 1
+#define F_TRACE 2
+#define F_RUNNING 4
struct gdbcnxn {
int fd;
unsigned state;
- unsigned sum;
+ unsigned txsum;
+ unsigned rxsum;
unsigned flags;
unsigned char *txptr;
unsigned char *rxptr;
@@ -68,7 +71,8 @@ void zprintf(const char *fmt, ...) {
void gdb_init(struct gdbcnxn *gc, int fd) {
gc->fd = fd;
gc->state = S_IDLE;
- gc->sum = 0;
+ gc->txsum = 0;
+ gc->rxsum = 0;
gc->flags = F_ACK;
gc->txptr = gc->txbuf;
gc->rxptr = gc->rxbuf;
@@ -86,7 +90,7 @@ static inline int tx_full(struct gdbcnxn *gc) {
static inline void gdb_putc(struct gdbcnxn *gc, unsigned n) {
unsigned char c = n;
if (!tx_full(gc)) {
- gc->sum += c;
+ gc->txsum += c;
*(gc->txptr++) = c;
}
}
@@ -100,14 +104,14 @@ void gdb_puts(struct gdbcnxn *gc, const char *s) {
void gdb_prologue(struct gdbcnxn *gc) {
gc->txptr = gc->txbuf;
*(gc->txptr++) = '$';
- gc->sum = 0;
+ gc->txsum = 0;
}
void gdb_epilogue(struct gdbcnxn *gc) {
unsigned char *ptr;
int len, r;
char tmp[4];
- sprintf(tmp,"#%02x", gc->sum & 0xff);
+ sprintf(tmp,"#%02x", gc->txsum & 0xff);
gdb_puts(gc, tmp);
if (tx_full(gc)) {
@@ -165,7 +169,7 @@ int gdb_recv(struct gdbcnxn *gc, unsigned char *ptr, int len) {
gdb_recv_cmd(gc);
} else if (c == '$') {
gc->state = S_RECV;
- gc->sum = 0;
+ gc->rxsum = 0;
gc->rxptr = gc->rxbuf;
}
break;
@@ -179,7 +183,7 @@ int gdb_recv(struct gdbcnxn *gc, unsigned char *ptr, int len) {
gc->state = S_IDLE;
} else {
*(gc->rxptr++) = c;
- gc->sum += c;
+ gc->rxsum += c;
}
}
break;
@@ -191,7 +195,7 @@ int gdb_recv(struct gdbcnxn *gc, unsigned char *ptr, int len) {
gc->chk[1] = c;
gc->state = S_IDLE;
*(gc->rxptr++) = 0;
- if (strtoul(gc->chk, NULL, 16) == (gc->sum & 0xFF)) {
+ if (strtoul(gc->chk, NULL, 16) == (gc->rxsum & 0xFF)) {
if (gc->flags & F_ACK) {
if (write(gc->fd, "+", 1)) ;
}
@@ -402,7 +406,21 @@ void handle_command(struct gdbcnxn *gc, unsigned char *cmd) {
/* silent (no-response) commands */
switch (cmd[0]) {
case 'c':
+ if (cmd[1]) {
+ x = strtoul((char*) cmd + 1, NULL, 16) | 1;
+ swdp_core_write(15, x);
+ }
swdp_core_resume();
+ gc->flags |= F_RUNNING;
+ return;
+ // single step
+ case 's':
+ if (cmd[1]) {
+ x = strtoul((char*) cmd + 1, NULL, 16) | 1;
+ swdp_core_write(15, x);
+ }
+ swdp_core_step();
+ gc->flags |= F_RUNNING;
return;
}
@@ -410,6 +428,7 @@ void handle_command(struct gdbcnxn *gc, unsigned char *cmd) {
switch (cmd[0]) {
case '?':
gdb_puts(gc, "S00");
+ gc->flags &= (~F_RUNNING);
swdp_core_halt();
break;
case 'H':
@@ -491,11 +510,7 @@ void handle_command(struct gdbcnxn *gc, unsigned char *cmd) {
// halt (^c)
case '$':
swdp_core_halt();
- gdb_puts(gc, "S00");
- break;
- // single step
- case 's':
- swdp_core_step();
+ gc->flags &= (~F_RUNNING);
gdb_puts(gc, "S00");
break;
// extended query and set commands
@@ -539,7 +554,17 @@ void handle_command(struct gdbcnxn *gc, unsigned char *cmd) {
gdb_epilogue(gc);
}
+static int pipefds[2] = { -1, -1 };
+
+void signal_gdb_server(void) {
+ if (pipefds[1] >= 0) {
+ char x = 0;
+ if (write(pipefds[1], &x, 1) < 0) ;
+ }
+}
+
void gdb_server(int fd) {
+ struct pollfd fds[2];
struct gdbcnxn gc;
unsigned char iobuf[32768];
unsigned char *ptr;
@@ -547,20 +572,66 @@ void gdb_server(int fd) {
gdb_init(&gc, fd);
+ debugger_lock();
+ if (pipefds[0] == -1) {
+ if (pipe(pipefds)) ;
+ }
+ debugger_unlock();
+
// gc.flags |= F_TRACE;
for (;;) {
- r = read(fd, iobuf, sizeof(iobuf));
- if (r <= 0) {
+
+ fds[0].fd = fd;
+ fds[0].events = POLLIN;
+ fds[0].revents = 0;
+ fds[1].fd = pipefds[0];
+ fds[1].events = POLLIN;
+ fds[1].revents = 0;
+
+ // check ahead of the poll, since we may have
+ // just resume'd a single-step that will have
+ // halted again by now
+ debugger_lock();
+ if (gc.flags & F_RUNNING) {
+ u32 csr;
+ if (swdp_ahb_read(CDBG_CSR, &csr) == 0) {
+ if (csr & CDBG_S_HALT) {
+ gc.flags &= (~F_RUNNING);
+ // todo: indicate specific halt reason
+ gdb_prologue(&gc);
+ gdb_puts(&gc, "S00");
+ gdb_epilogue(&gc);
+ }
+ }
+ }
+ debugger_unlock();
+
+ r = poll(fds, 2, (gc.flags & F_RUNNING) ? 10 : -1);
+ if (r < 0) {
if (errno == EINTR) continue;
- return;
+ break;
+ }
+ if (r == 0) {
+ continue;
+ }
+ if (fds[0].revents & POLLIN) {
+ r = read(fd, iobuf, sizeof(iobuf));
+ if (r <= 0) {
+ if (errno == EINTR) continue;
+ return;
+ }
+ len = r;
+ ptr = iobuf;
+ while (len > 0) {
+ r = gdb_recv(&gc, ptr, len);
+ ptr += r;
+ len -= r;
+ }
}
- len = r;
- ptr = iobuf;
- while (len > 0) {
- r = gdb_recv(&gc, ptr, len);
- ptr += r;
- len -= r;
+ if (fds[1].revents & POLLIN) {
+ char x;
+ if (read(fds[1].fd, &x, 1) < 0) ;
}
}
}
