manual gdb and linux

[Evanok]

Hello,

Thanks for this great tool. I am trying to use your repo to have gdb working on my teensy4.1.
But this is not working. I am not sure that my process is correct.

This is my current process:

• adding the two cpp files gdbstub.cpp and TeensyDebug.cpp into my cmakefile
• Replacing USB_SERIAL CFLAGS by USB_DUAL_SERIAL
• Using --ggdb and -O1 as CFLAGS instead of -O3. This is a custom firmware and for unknown reason my
  firmware does not boot with -O0 :(.
• Include TeensyDebug.h into my firmware code.
• Adding debug.begin(SerialUSB1); in my setup code to enable the second serial port using for gdb.
• Calling halt_cpu() at the end of my setup function.
• Flashing the firmware
• Now I can see two serial port available instead of one. I have now /dev/ttyACM1 available
• Running the gdb builtin from my toolchain with the elf firmware binary:

[arthur * gdb_test] arm-none-eabi-gdb PARDI_Firmware.elf -ex "target remote /dev/ttyACM1"
GNU gdb (Arm GNU Toolchain 13.2.rel1 (Build arm-13.7)) 13.2.90.20231008-git
This GDB was configured as "--host=x86_64-pc-linux-gnu --target=arm-none-eabi".
(...)
Reading symbols from PARDI_Firmware.elf...
Remote debugging using /dev/ttyACM1
Ignoring packet error, continuing...
warning: unrecognized item "timeout" in "qSupported" response
Ignoring packet error, continuing...
Remote replied unexpectedly to 'vMustReplyEmpty': timeout
(gdb) exit

From my I can see in my first serial port, the loop is running even if I am calling the halt cpu function in the setup. Is it expected?
Is there something wrong in my process?

Thanks,
Arthur.