arm-none-eabi-gdb debugging with openocd

the simplest thing to debug your RP2040 chip is using secondary pico as picoprobe, then running openocd. I assume you're was ready with your pico debugprobe

identify your TTY

check with sudo dmesg, the run a command like this sudo chmod 666 /dev/ttyACM0

openocd

openocd -f interface/cmsis-dap.cfg -f target/rp2040.cfg -c "adapter speed 5000"

cmake

make sure your ELF was build with cmake -DCMAKE_BUILD_TYPE=Debug -DPICO_BOARD=pico ..

flashing

openocd -f interface/cmsis-dap.cfg -f target/rp2040.cfg -c "adapter speed 5000" -c "program hello_usb.elf verify reset exit"

without sudo