Re: [Qemu-devel] qemu-arm in various flavours and circumstances

[Paul Brook <paul@codesourcery.com>]

On Saturday 07 August 2004 13:37, Lennert Buytenhek wrote:
> OK, I built a number of different ARM binaries with different toolchains,
> a few different versions of qemu, and ran them under a few different
> circumstances.
<snip>
> The results
> -----------
> bigendian:
> - The bigendian binaries (armv?eb, armv?teb) always result in
>   "Error loading $NAME_OF_BINARY", under every version of qemu
>   (I didn't muck with WORDS_BIGENDIAN.)

I haven't tried big-endian binaries. I suspect you won't be able to run both 
big and little endian binaries with the same version of qemu.

> setarch i686:
> - An FC2-compiled qemu-arm, when ran on an FC2 host without setarch i686,
>   under each and every circumstance gives a sig11.
> - An FC2-compiled qemu-arm, when ran on an FC2 host with setarch i686,
>   always behaves the same as a RH73-compiled qemu-arm when ran on an FC2
>   host.  Meaning, sometimes it works, sometimes it doesn't -- see below.

I suspect this is a generic qemu problem, not specific to qemu-arm.

> When using either a RH73-compiled qemu or setarch i686:
> - All arm-unknown-linux-gnu and armv4e-redhat-linux toolchains produce
>   binaries that work under qemu.
> - There is no difference in results between qemu 0.6.0 and qemu 20040806.
> - There is no difference in results between armv5e and armv5te binaries.
> - All armv5(t)e binaries give a sig11 under qemu 0.6.0 and qemu 20040806,
>   but under qemu 20040806 plus Paul's three patches they give sig4:
>   "qemu: uncaught target signal 4 (Illegal instruction) - exiting"

armv5 support is still incomplete, even with my patches. Thumb state, and the 
interworking branch instruction (bx) are still missing. I'm working on it 
(slowly).

A side-effect of my armv5e patch is that more illegal/unrecognised 
instructions are detected. Without the patch they are probably misinterpreted 
as a nonsensical form of a different instruction.

Paul