On Aug 14, 2017, at 2:30 PM, Cufi, Carles <Carles.Cufi@nordicsemi.no> wrote:

Hi Scott,

-----Original Message-----
From: Scott Nelson [mailto:scott@scottnelson.co]
Sent: 14 August 2017 20:06
To: Cufi, Carles <Carles.Cufi@nordicsemi.no>
Cc: zephyr-users@lists.zephyrproject.org
Subject: Re: [Zephyr-users] NRF51822 hanging

The board is one of these: http://www.waveshare.com/nrf51822-eval-
kit.htm I have been flashing it with STLink + OpenOCD and I’m trying to
figure out how I can debug the chip with that setup + GDB. I am not
using the Nordic dev kit. Let me know if there’s any additional info I
can provide and thanks for you help!

Is there a way I can override the Zephyr fault hander so that I could,
for example, flash an LED or repeatedly log something to the serial
output?

Yes, since you are using the BLE controller this could be a controller assert (which leads to panic). Assuming you are using the latest master (and you should if you are not, since there have been many fixes to the BLE controller recently) then you can override it here:

https://github.com/zephyrproject-rtos/zephyr/blob/master/arch/arm/core/fatal.c#L45

A CPU fault and a BLE controller assert should all end up there.

Regards,

Carles