Re: [Qemu-devel] [PATCH 1/16] ARM Add ARM 920T identifiers

[Vincent Sanders]

On Tue, May 26, 2009 at 11:16:18AM +0100, Paul Brook wrote:
> > > It could be a major problem if you start playing with ARM/Thumb
> > > interworking.
> >
> > I'm curious.  How would code built for ARMv4T interworking fail on an
> > ARMv5T emulator?
> 
> Usually the reverse is true - code works on v5, but fails on v4t.
> However the following will work on armv4t and fail on armv5:
> 
> test:
> adr r0, 1f
> orr r0, r0, #1
> str r0, [sp, #-4]!
> ldr pc, [sp], #4
> 1:
> bx lr
> 
> Admittedly this is a fairly contrived example, but the circumstances aren't 
> completely implausible. Imagine someone using the low bit of a pointer as an 
> additional flag, and relying on the hardware ignoring that bit.

ok, aside from that (very very unlikey) case are you going to accept
the new patch with the comment or do I need to alter translate.c to
perform V4 operations and add the v5 feature flag.

I am happy to do that if there is any chance of it being
accepted. However I am now at the point I feel I am just wasting my
time and you have no intention whatsoever of accepting anything we
submit. 

If you have no desire whatsoever to accept our work, thats fine, and I
shall desist from attempting to contribute any futher. Please
communicate your intentions clearly so there is no futher ambiguity,
thankyou.

-- 
Regards Vincent