nrf-boot

A secure bootloader for nRF9160 and nRF5340.

Plug a micro USB cable to nRF9160-DK or nRF5340-DK.

For other boards, connect UART pins as follows:

nRF9160	UART-to-USB adapter
P0.29 (TX)	RX

nRF5340	UART-to-USB adapter
P0.20 (TX)	RX

UART baud rate: 115200

Connect SWD pins as follows:

nRF9160 or nRF5340	Segger JLINK adapter
SWDIO	SWDIO
SWDCLK	SWCLK
Ground	Ground

Set up your environment

$ sudo apt install gcc-arm-linux-gnueabi
$ export CROSS_COMPILE=arm-linux-gnueabi-

Get sources and build

$ git clone --recursive https://github.com/machdep/nrf-boot
$ cd nrf-boot
$ make clean all

Program the nrf91 chip using nrfjprog

$ make flash-nrf91

Program the nrf53 chip using nrfjprog

$ make flash-nrf53