Raspberry Pi Pico

Mac
brew install minicom
minicom -D /dev/tty.usbmodem1234561 -b 115200
Using Picoprobe with OpenOCD
Same for all platforms
src/openocd -f interface/picoprobe.cfg -f target/rp2040.cfg -s tcl
Connect GDB as you usually would with
target remote localhost:3333
Getting started with Raspberry Pi Pico
Using Picoprobe with OpenOCD 64