Fiasco.OC-UX on MIPS?

Matthias Lange matthias.lange at
Thu Aug 22 14:15:55 CEST 2019

Hi Paul,

On [22-08-2019 13:33], Paul Boddie wrote:
> On Monday 19. August 2019 00.31.16 Adam Lackorzynski wrote:
> > Hi Paul,
> > 
> > UX is an interesting way of virtualizing a kernel and gives interesting
> > insights into both Fiasco and Linux. I guess with some work it would be
> > well possible to make this work on MIPS.
> After writing my message, I did think of pursuing a simpler, iterative 
> approach to making the kernel run as a Linux process, ultimately employing 
> most of the same techniques but without trying to adapt the existing UX code.
> > But, before going on this endeavor what about QEMU? It should be much
> > quicker and simpler to run it through QEMU,
> This did occur to me: after all, what is mostly needed is a way of emulating 
> the privileged instructions, and QEMU is a general framework for achieving 
> this. (The documentation isn't completely clear about whether I would end up 
> emulating everything even on the same architecture.)
> So, I have built Fiasco and L4Re for the MIPS Malta platform, and it seems to 
> be possible to launch a system using the Makefile. For instance:
> make O=mybuild qemu E=hello

Did you set the correct qemu options in your Makeconf.boot? And you may have
to specify the correct platform type because the default afik 'boston', like

  make O=mybuild qemu PT=malta E=hello

Also check the qemu cmdline that it contains "-M malta".

> However, I imagine that either a graphical example is needed where the SDL 
> interface for QEMU is being used, or that some options are required to get 
> QEMU to use a simple serial console. There appear to be some options and the 
> possibility to do something like this:
> make O=mybuild qemu E=hello QEMU_OPTIONS='-nographic'
> Maybe even the machine type is necessary amongst the options as well. This 
> doesn't seem to produce output, though.
> I have to ask: what do people actually use when developing L4Re and Fiasco?

Qemu is always a good start. It allows very quick development and test cycles.
In the end you of course have to test on hardware.


> Paul
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Matthias Lange, matthias.lange at, +49-351-41 888 614

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