This is an old revision of the document!

01. [??p] Creating the Firmware Image Package

This package will contain bl2, bl31 and bl33. The Secure OS (bl32) is outside the scope of this lab; even if we did bother to include it, it would just be there, doing nothing.

Following this exercise, we should be able to reach the first step of the booting sequence that can be interactive; meaning that we'll be able to interact with a shell implemented in bl33.

[??p] Task A - bl31: the Runtime Software

For this component we'll be using the Trusted Firmware-A project. Although it contains reference implementations for the other bootloaders as well, we are going to use it strictly for bl31. The other have more complete and widely recognized alternatives available.

We recommend reading the documentation moving forward. Take a close look at the build options in particular.

Normally, we'd be using the official TF-A but at the moment it seems to have a linker script bug for our platform. Reason why we use the NXP fork of TF-A.

The default target platform is ARM's Fixed Virtual Platform (FVP), a simulator. That is not our platform…
To specify that we don't have a bl32 for it to initialize, pass it SPD=none.
You don't have to build everything. Just make … bl31.