Re: [Qemu-arm] [Qemu-devel] Crash when running hello-world unikernel for ARM

[Peter Maydell]

On 10 April 2018 at 09:16, Ajay Garg <address@hidden> wrote:
> On Tue, Apr 10, 2018 at 1:08 PM, Peter Maydell <address@hidden> wrote:
>> What hardware (what CPU, board, etc) is this "rumprun" software
>> expecting to run on?
>
> Yep, just to ensure that there are no cross-compiling issues, I am
> building rumprun on the pseudo-real hardware itself.
> In our case, the pseudo-real hardware are :
>
> a)
> An ARM32 "virt" hardware/machine in a qemu environment
> (https://translatedcode.wordpress.com/2016/11/03/installing-debian-on-qemus-32-bit-arm-virt-board/)
>
> Once I start  this machine, all environment is arm32, and I compile
> rumprun within this environemnt without any cross-compiling.
>
> b)
> A beaglebone-green-wireless.
> This is a arm32 machine bottoms-up, so no question of cross-compiling
> whatsoever here :)
>
> In both cases, I then use qemu-system-arm (on the "virt" machine, and
> beaglebone-green-wireless itself).

That's telling me what setups you're trying to compile in,
which doesn't correspond necessarily to what the guest
OS is built to run on.

> One query : It is apparent that there is nested qemu-virtualization in
> step a), could that be an issue?

Why are you running this in a nested setup? I don't understand
the purpose of doing that. It would be simpler and faster to
just run the guest on a QEMU running in your native host system.

Assuming this is the source for the guest you're trying to run:

https://github.com/rumpkernel/rumprun/tree/master/platform/hw/arch

that suggests that the only Arm board it supports is "integrator"
(which is an absolutely ancient devboard with very little memory,
no PCI and no virtio support). You need to confirm what Arm hardware
this 'rumpkernel' is actually intended to run on, and then give QEMU
the right command line arguments to emulate that hardware. I can't
really help any further, I'm afraid -- you need somebody who knows
about this guest OS.

thanks
-- PMM