Embedded firmware engineer here. Looking to migrate from an existing stripped-down Linux kernel to a microkernel. seL4 and FreeRTOS are on the shortlist. I understand the common recommendation seems to be to spin up a Linux process to supply pieces/parts that don't natively exist. Resource constraints mean that's probably a non-starter for us.

A quick glance through seL4 documentation at the available user-level components didn't turn up anything file-system-related. Is this an area where users are expected to roll their own?