qemu-mips illegal instruction

[Sean Bruno]

On Fri, 2014-04-04 at 11:11 -0700, Sean Bruno wrote:
> On Fri, 2014-03-28 at 11:00 -0700, Sean Bruno wrote:
> > > This problem seems to be caused by a endian issue in qemu-mips.  Ed
> > > Maste found the culprit and I've applied it here:
> > > 
> > > https://github.com/seanbruno/qemu/commit/05ee8495804599b52a88eb36b13ea9c06b3207cd
> > > 
> > > Which is my combined tracking branch for qemu and sson's bsd-user
> > > branch.
> > > 
> > > I'm currently tracking an "illegal instruction" on exit issue that seems
> > > to happen on application exit causing a crash.
> > > 
> > > sean
> > 
> > 
> > I've been tracking qemu upstream with sson's patches and massaging
> > things here and there with the bsd-user mode qemu.
> > 
> > https://github.com/seanbruno/qemu/tree/bsd-user
> > 
> > That in combination with sson's kernelmod/userland tool allows me to
> > "chroot" into a mips environment suitable for building packages.
> > http://people.freebsd.org/~sson/imgact_binmisc/imgact_binmisc.diff
> > 
> > Currently, if I explicitly pass a shell into the chroot command, I have
> > no issues and all is well.  e.g.  chroot /mipsbuild /bin/sh
> > 
> > If I do not explicitly pass a shell, I get an illegal instruction core
> > dump from qemu-mips on exit from any command I run in the chroot:
> > 
> > chroot /mipsbuild
> > uname -a
> > <uname output>
> > (Illegal Instruction)[coredump]
> > 
> > This breaks poudriere right now.
> > 
> > 
> > More or less this is my recipe:
> >       - built a mips32 world for "chroot" purposes:
> >       - use sson's binmisc ELF interceptor thing:
> >       - run binmiscctl:
> > binmiscctl add mips32 --interpreter "/bin/qemu-mips" --magic "\x7f\x45
> > \x4c\x46\x01\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00
> > \x08" --mask "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff
> > \xff\xff\xff\xfe\xff\xff" --size 20 --set-enabled
> > 
> > 
> >       - chroot /mipsbuild
> >       - uname -a (Illegal Instruction and coredump ON EXIT)
> > 
> >       - chroot /mipsbuild /bin/sh
> >       - uname -a (works everytime)
> > 
> > 
> > sean
> 
> I've narrowed this down with some help from #bsdmips:
> 
> env SHELL=/bin/sh chroot /mipsbuild  --> no issues running commands
> 
> env SHELL=/bin/csh chroot /mipsbuild
> env SHELL=/bin/tcsh chroot /mipsbuild --> both of these cause illegal
> instructions in qemu-mips
> 
> Juregen came up with a patch that makes the amd64 version of qemu-mips
> work, so there's no need to xbuild the i386 version now, so thanks for
> that!
> 
> sean
> 
> ref https://github.com/seanbruno/qemu/tree/bsd-user
> 
> 


And finally, thanks to peter, we have a 1bit change for 32bit mips that
seems to work.

https://github.com/seanbruno/qemu/commit/d62553b108aa27c0c020dbb771d29f8673807a3b


Doing a test run now.  this might mean that 32bit mips packages might
exist this weekend in some form.

sean
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 473 bytes
Desc: This is a digitally signed message part
URL: <http://lists.freebsd.org/pipermail/freebsd-hackers/attachments/20140404/e2ad5a7f/attachment.sig>