The zcu102 has a quirk where Linux will perform SMC instructions to configure hardware resources during the boot process. This bypasses the seL4 kernel and executes commands at EL3. This kills the worst-case execution time guarantees, so they need to be avoided at all costs. They can also be used to turn cores on or off, which is problematic.
DornerWorks implemented a solution where SMC calls are trapped to seL4 and handled by the VMM. Since some of these calls are necessary for Linux to boot, a new SMC capability is created which when invoked, will have the seL4 kernel perform only the SMC commands it has been configured to run. Most of these changes have recently been merged, which means an upstream-compatible zcu102 configuration can be released.
I should be able to create the PRs within the next week, and I can ping you when its ready.
From: An,Jianjun via Devel