Want to run L4Re on Raspberry PI.

[Paul Boddie]

On Wednesday 29. May 2019 08.39.11 Matthias Lange wrote:
> 
> On [28-05-2019 21:21], Lei Zhou wrote:
> > Thanks Paul for your prompt response.  I will give it try and see how it
> > goes.    Regards,   Lei
> I just want to add two things to Paul's very good description.
> 
> First, have you checked our build instructions and how tos on our github [1]
> ?

Maybe there should be some updates to l4re.org to communicate any new advice.

> And second, which Raspberry Pi model are you targeting? Newer (> gcc 4.7)
> cross-toolchains seem to have dropped support for ARMv6k. While you still
> can compile L4Re/Fiasco for that architecture the binaries will not run
> later.

One thing I did forget to mention was the cross-toolchains, which was 
regrettable. I believe that the Debian toolchains in Debian 9 (Stretch), 10 
(Buster) or unstable (Sid) should be good enough, but as is noted above, the 
architecture variant of earlier Raspberry Pi models (and the Pi Zero) is not 
supported in Debian any more (which is why Raspbian exists).

I suppose that L4Re could be compiled natively within Raspbian if that is 
already deployed. I don't remember if there are any complications for ARM 
about code output, but looking at the src/l4/mk/arch/Makeconf.arm, it seems 
that a fairly standard arm-linux-gnueabihf toolchain is indicated. (I suppose 
I could be thinking about certain "bare metal" configurations requiring 
differently-configured compilers.)

Otherwise, I had some success with Buildroot in generating toolchains, these 
being needed for my soft-float MIPS configuration.

Paul

> [1] https://github.com/kernkonzept/manifest/wiki