`hf` should at least respond to inquiries when it's upset about hubris

[rmustacc]

The only time that would be a problem is if we're still booting. In general, once we've booted and told the SP, we expect that the mux will be returned to the hf task.

[mkeeter]

Also, the hf task always muxes the flash to the SP when the task starts up. @jgallagher points out in #1145 that if the task has died for some reason – but the rest of the system is in A0 – this could steal the flash away from the host!

[nathanaelhuffman]

just to link this: #1172 this is the issue about expected muxing away

[cbiffle]

Also, the hf task always muxes the flash to the SP when the task starts up. @jgallagher points out in #1145 that if the task has died for some reason – but the rest of the system is in A0 – this could steal the flash away from the host!

Since the mux state is maintained by a GPIO, it should be straightforward to make hf respect its current state on task restart.