RTEMS SMP on Raspberry Pi 2

Gedare Bloom gedare at rtems.org
Thu Aug 1 16:57:36 UTC 2019

On Thu, Aug 1, 2019 at 10:33 AM Ricardo Gomes (1161078)
<1161078 at isep.ipp.pt> wrote:
> Helo,
> First of all, thank you for your response.
> You are correct, it freezes at the point it jumps to RTEMS entry point address.
> I cannot understand why it works with the non-smp samples and fails with smp samples, should I change the address?
You might use objdump to verify the expected instructions at the start
address. I don't see that the starting point should differ between SMP
and UP, but there are some SMP-specific instructions in the start
sequence (bsps/arm/shared/start/start.S), are they being reached?

I don't have experience with the RPi2 or access to the board, so I
can't offer much beyond that.

> ________________________________
> De: Gedare Bloom <gedare at rtems.org>
> Enviado: 1 de agosto de 2019 04:17
> Para: Ricardo Gomes (1161078) <1161078 at isep.ipp.pt>
> Cc: devel at rtems.org <devel at rtems.org>
> Assunto: Re: RTEMS SMP on Raspberry Pi 2
> On Thu, Aug 1, 2019 at 4:49 AM Ricardo Gomes (1161078)
> <1161078 at isep.ipp.pt> wrote:
> >
> > Hello everyone,
> >
> > I'm trying to collect some results of some experiments that I'm doing related with synchronization mechanisms for SMPs.
> > So far, I have the results for QEMU but I'm trying to use a Raspberry Pi 2 to obtain results in real hardware.
> >
> > I saw the new patches that were recently added for the raspberry pi bsp and as mentioned in the emails related to the new patches I changed the start address to 0x200000.
> >
> > However, I have a problem running my samples in the board. The kernel compiles without any problem. I'm using the following commands to compile it:
> >
> > arm-rtems5-objcopy -Obinary
> >
> >
> >
> > Now the issue occurs when I try to execute my tests for SMP, as the kernel freezes during the boot loader first stage.
> >
> > As a side note, when I compile and execute something para single processor na RPi2 I don't have any issue. The issue only occurs when dealing with SMP.
> >
> > Can someone help me in figuring out what I'm doing wrong?
> >
> Can you clarify what is the "boot loader first stage"? Usually, that
> is pre-kernel code, since it will load the binary image of the kernel,
> so it is strange to see different behavior based on different compiled
> kernels. Unless it is freezing at the point it jumps to RTEMS entry
> start address.
> > Thanks in advance.
> > Regards,
> > _______________________________________________
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> > devel at rtems.org
> > http://lists.rtems.org/mailman/listinfo/devel

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