Microboot 2
The next stage of the boot sequence is Microboot 2 (MB2). The sequence is as follows:
In step 2, MB2 has ability to utilize QSPI, eMMC, or UFS as the boot device for the remaining boot payloads. This is determined through the NV Partition Table settings.
MB2 loads and validates additional OEM firmware that configures the SoC to run more complex software components. The additional firmware components are as follows:
| Firmware Component | Description |
|---|---|
| Audio Processor Engine Firmware (APE-FW) | Provides the facilities for audio processing. |
| ATF/TOS image | Provide EL3 and Secure EL1 support. |
| Functional Safety Island Firmware (FSI-FW) | Provide the monitoring and reporting of functional safety errors. |
| Realtime Engine Firmware (RCE-FW) | Provides the realtime camera processing engine |
| SPE-FW | Provide debugging support in standard builds |
| Display Control Engine Firmware (DCE-FW) | Provides the realtime display processing engine. |
| Foundation image | Provides the Hypervisor stack and servers. |