1# Building MCUBoot with nRF52840 CC310 enabled
2
3## Pre-prerequisites
4
5Clone [nrfxlib](https://github.com/NordicPlayground/nrfxlib) next to the mcuboot root folder. So that it's located `../nrfxlib` from mcuboots root folder.
6
7## Building
8
9make sure `root-ec-p256.pem` is set as the certificate and that `CONFIG_BOOT_SIGNATURE_TYPE_ECDSA_P256` is selected not `CONFIG_BOOT_SIGNATURE_TYPE_RSA` in `prj.conf` of `boot/zephyr`.
10Since it defaults to tinycrypt you'll have to go into `menuconfig` and change the implementation selection to `cc310` or also set this in `prj.conf`.
11
12```
13mkdir build && cd build
14cmake -GNinja -DBOARD=nrf52840dk_nrf52840
15ninja flash
16```
17
18Build a hello world example in zephyr and sign it with imgtool.py with the `root-ec-p256.pem` and flash it at `FLASH_AREA_IMAGE_0`.
19