# Overview

The secure bootloader for RSL15 is a reference application, called secure_bootloader, which can be used to develop an end product bootloader that operates in a secure manner. The application has the following four modes providing increasing levels of secure operation, available as needed depending on the end product's use cases:

1. Basic bootloader (non-secure)
2. Secure bootloader (maintains authenticated Root of Trust set up by the ROM)
3. Secure bootloader with secure storage
4. Secure bootloader with secure storage and device attestation

More detailed information about these four modes is found in Chapter 1 "RSL15 Secure Bootloader Usage Options" on page 1

For more information about this topic, see: