Questions about Fiasco.OC scheduler and L4Linux

Adam Lackorzynski adam at
Wed Mar 22 00:55:53 CET 2017

Hey Marc,

On Tue Mar 21, 2017 at 08:31:06 +0100, Marc CHALAND wrote:
> I'm doing a study to port old software on top of Fiasco.OC. This soft uses
> routines which blocks thread scheduling between EnterRegion and LeaveRegion
> call. Is there any equivalent on TUDOS ? Did somebody already get this
> challenge ?

Yes, that's what the vCPU model is basically about, i.e. supporting
execution style of an OS. With this you can have EnterRegion and
LeaveRegion by disabling/restoring virtual interrupts.

> I would like to know if L4Linux uses Fiasco.OC scheduler or a user land one
> ?

It uses Linux's own scheduler.

> For our i.MX7d board, Freescale provides Linux drivers on 4.1. I don't know
> yet how many drivers we will need. Do you think it is better to port
> drivers from 4.1 to L4Linux 4.3 or later or get a L4Linux 4.1. I have no
> idea about the complexity on doing this.

With a i.MX7d you have hardware support for virtualization, so what
about using that, i.e. running normal Linux in a VM? Getting an L4Linux
for an older version is of course possible but a bit of work.


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