Cross testing applications under QEMU

[Michael Hope]

On 26 April 2012 13:58, Mans Rullgard <mans.rullgard at linaro.org> wrote:
> On 26 April 2012 02:39, Michael Hope <michael.hope at linaro.org> wrote:
>> We use QEMU to test programs built by the toolchain binary release for
>> correctness.
>
> Is that really such a great idea?  Qemu is generally less strict than
> actual hardware with things like alignment restrictions.  This is fine
> for running software on a foreign architecture, which is the typical
> use case for emulators, and it is much faster than implementing strict
> checks for things no correct program should ever do.
>
> A few years ago, Codesourcery released an ARM compiler, binaries from
> which immediately crashed on real hardware.  They had only tested the
> output in Qemu, never on hardware.  Since then, many bugs in Qemu have
> been fixed, but I would still not trust it for validating a compiler.

Agreed, but this is more of a final validation and integration test.
The same source tarball has been bootstrapped and a range of tests run
on real hardware.  This is testing that the later binary build builds
programs and the programs run.

QEMU is fine for a development test.  On reflection, not for the final
release test.

-- Michael