gdb: break when a message is recived during execution

This behaviour implements support for breaking the add-in during
execution by pressing ^C in GDB without setting a breakpoint beforehand.
This commit is contained in:
redoste 2023-05-27 19:06:29 +02:00
parent 33dae5d218
commit 02a97719ac
Signed by: redoste
SSH Key Fingerprint: SHA256:Y1z/cbVN8OVoFPXzVgklSqoZnyQQ/PQM8YwhMtxMk90
1 changed files with 32 additions and 7 deletions

View File

@ -37,7 +37,11 @@ static uint32_t gdb_unhexlify(const char* input_string)
return gdb_unhexlify_sized(input_string, strlen(input_string));
}
static bool gdb_started = false;
static enum {
GDB_STATE_STOPPED,
GDB_STATE_FIRST_BREAK,
GDB_STATE_STARTED,
} GPACKEDENUM gdb_state = GDB_STATE_STOPPED;
static void gdb_send(const char *data, size_t size)
{
@ -460,10 +464,6 @@ static void gdb_handle_single_step(gdb_cpu_state_t* cpu_state)
void gdb_main(gdb_cpu_state_t* cpu_state)
{
if (cpu_state != NULL) {
gdb_send_stop_reply();
}
if (gdb_single_step_backup.single_stepped) {
if (gdb_single_step_backup.channel0_used) {
ubc_set_breakpoint(0, gdb_single_step_backup.channel0_addr, UBC_BREAK_BEFORE);
@ -479,6 +479,10 @@ void gdb_main(gdb_cpu_state_t* cpu_state)
gdb_single_step_backup.single_stepped = false;
}
if (cpu_state != NULL) {
gdb_send_stop_reply();
}
while (1) {
char packet_buffer[256];
ssize_t packet_size = gdb_recv_packet(packet_buffer, sizeof(packet_buffer));
@ -538,9 +542,28 @@ void gdb_main(gdb_cpu_state_t* cpu_state)
}
}
static void gdb_notifier_function(void)
{
// We ignore fxlink notifications when we're already inside GDB code.
if (ubc_dbh_lock || gdb_state != GDB_STATE_STARTED)
return;
// We make sure we are called during a USB interrupt.
if (usb_interrupt_context == NULL)
return;
// And we make sure an other step break is not already set up.
if (gdb_single_step_backup.single_stepped)
return;
gdb_cpu_state_t fake_state = {};
fake_state.reg.pc = usb_interrupt_context->spc;
gdb_handle_single_step(&fake_state);
}
int gdb_start(void)
{
if (gdb_started) {
if (gdb_state != GDB_STATE_STOPPED) {
return GDB_ALREADY_STARTED;
}
@ -553,10 +576,12 @@ int gdb_start(void)
return GDB_USB_ERROR;
}
usb_open_wait();
usb_fxlink_set_notifier(gdb_notifier_function);
ubc_set_debug_handler(gdb_main);
gdb_started = true;
gdb_state = GDB_STATE_FIRST_BREAK;
gdb_main(NULL);
gdb_state = GDB_STATE_STARTED;
return 0;
}