I know that Linux has been made to run on top of seL4. Has anything comparable been attempted with seL4. I note that DragonFly BSD appears to use some sort of microkernel, but I doubt that it would be anywhere are secure and performant as seL4.
In the past we’ve run rump kernels on top of seL4.
I believe that the rumprun support has bitrotted in the meantime, so probably won’t work on the current version of seL4.
Note that this is a different approach to how we run Linux on seL4 - Linux on seL4 uses (hardware) virtualisation technologies to run Linux in a VM on seL4. You could try to run virtualised BSD in this way as well, though we haven’t done that yet.
My goal is run a secured/hardened BSD on seL4. Since I’m focused on server environments, I would prefer to have drivers running directly on seL4 and then a paravirtualised (I hope I’m using the correct terminology) BSD with further hardening along the lines of OpenBSD and/or HardenedBSD.
And the target hardware would be RISC-V. The big picture being that the system is built upon TCB hardware and microkernel.
I’m not aware of any work that has run BSD kernels instead of Linux kernels on top of the seL4 hypervisor extensions. In theory the seL4 APIs should be generic enough to support both, (and if that wasn’t the case then there would be a good argument for changing them). And then assuming that the BSD kernel had virtio driver modules then you could use a native network driver in a separate seL4 component providing a virtio network interface to the paravirtualized BSD kernel running as a guest inside a VM component.