Using OpenOCD and GDB with nRF52832 (PineTime)

gistfile1.txt

Based on the build from lupyuen/pinetime-rust-mynewt
Uses a Raspberry Pi to run OpenOCD which connects to the nRF52 with SMD
If required, GDB then runs on top of OpenOCD (OpenOCD has quite a few commands without GDB)

Start OpenOCD in a terminal window

Currently, I am using the lupyuen/pinetime-rust-mynewt script to flash the nRF52 app which then leaves OpenOCD running, wiating for connections on port 3333 & 4444
TODO - add instrutions to start OpenOCD on its own
pi@raspberrypi:~/pinetime-rust-mynewt $ openocd/bin/openocd -f scripts/nrf52-pi/swd-pi.ocd

Interacting with OpenOCD
Once OpenOCD is running, it is expecting a telnet session on port 4444 so you can issue commands
At a terminal prompt on the Raspberry Pi, type the command: telnet 127.0.0.1 4444
This will open a telnet session to type commands into OpenOCD (see commands below)

Interacting with GDB
Once OpenOCD is running, it is expecting a session on port 3333 so you can use GDB on top of OpenOCD
At a terminal prompt on the Raspberry Pi, type the command: arm-none-eabi-gdb
At the gdb prompt, type the command: target extended-remote 127.0.0.1:3333




OpenOCD commands

reset halt
reset
halt
init
exit (quit?)
flash fillw 0x10001208 0xffffff00 0x01
flash banks
flash list
nrf5 mass-erase
flash write_image image.bin
reg
reg pc 0x12b9a
reg r3 0x0x00000004
mdw 4 # view reset vector

gdb commands

x 0x0
x 0x4 # view reset vector
x 0x10001208 # view APPROTECT register
monitor reset halt
i r # view registers
i r r3
set $pc = 0x12b9a
set $r3 = 0x4
si # step instruction
layout asm