in reply to Matt Campbell

@matt we are booting with U-Boot. It's (roughly) ROM -> xbl_sec (el3) -> sbl1 (uart & hw init) -> tz -> hypervisor (gunyah) -> u-boot

everything before u-boot is proprietary, we are hoping to be able to optionally disable hyp and get EL2 for KVM but work will be needed (probably from the community) to get the DSPs to work in that case so we have audio