[NSWI004] Trouble with process initiation

[Martin Koreček]

Hello.

We are unable to initiate the userspace processes. We set the $ra and 
$status in the process thread context and also set the SP, which seems 
to be the problem.
It seems like a TLB exception is raised inside cpu_switch_ context when 
SP should be modified, which maybe makes sense. Using the virtual SP 
address perhaps isn't a good idea, since cpu_switch_context isn't 
running in the correct AS yet (or so I think). Neither does using the 
physical or kernel address.
Are we doing it completely wrong, or is there a simple fix to make this 
work?

(the commit SHA is bc32b91866426118e65dcc3e8c8d788ca8005893)

Thank you in advance for any suggestions.
Regards,
Martin Koreček (and team sleeping_turtle)