ppc64le (+ ppcle) magic is missing in debian/binfmt-update-in

[jaejunh]

1. binfmt-update-in doesn't have definition for ppc64le_{magic,mask}.

I temporarily created one using hexdump output:

hexdump -C /bin/bash | head -n 2
00000000 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 |.ELF............|
00000010 02 00 15 00 01 00 00 00 70 14 02 10 00 00 00 00 |........p.......|

hexdump -C /bin/sh | head -n 2
00000000 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 |.ELF............|
00000010 03 00 15 00 01 00 00 00 ac 4e 00 00 00 00 00 00 |.........N......|

2. I added a small patch of 32-bit usermode "qemu-ppcle" (being subarch of ppc64le)

I am in the porting powerpcel (32bit ppc LE) ubuntu 14.04, and
got successfully chroot with this qemu-ppcle patch and it looks very promising (i.e.
build perl looks ok)

3. I am attaching patch for above two. You can ignore/reject if necessary.

Thanks.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "patch for ppc64le magic + qemu-ppcle" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Serge Hallyn (serge-hallyn)]

Thanks for submitting this patch. I'll aim to get it into 14.10 and 14.04. Is there a particular way you'd recommend testing this, or should i simply download the ppc64le 14.10 cd image and try chrooting into it?

[jaejunh (jaejunh)]

Hi, Serge,

1. You can do "full" test by downloading ppc64le 14.10 iso, but quick test is also possible by following:

In your host pc(amd64?) 14.10, where you've installed above qemu-user-static (qemu-ppc64le),

  apt-get download coreutils:ppc64el bash-static:ppc64el
  # or just wget those two from launchpad 14.10
  dpkg-deb -x coreutils*.deb /tmp/ppc64el
  dpkg-deb -x bash-static*.deb /tmp/ppc64el
  ln -s /tmp/ppc64el/bin/bash-static /tmp/ppc64el/bin/bash
  cp /usr/bin/qemu-ppc64le-static /tmp/ppc64el/usr/bin

2. Now really tiny/broken chroot env is setup by 1. Now chroot,
 sudo su chroot /tmp/ppc64el

  If you see, "bash-4.3#" prompt, now you know it's successfully executed "ppc64el binary"
  using binfmt_misc.

Note: FYI, you can try: "ls" in chroot environment, yet it would not work since it cannot find
/lib64/ld64.so.2. However, static binary "echo" would work without problem!

If you get into any problem, please let me know.

Thank you!

PS. I still want "powerpcel" patch part committed too, although no community (known) is working on this
except me since I rely on this patch to work on my current porting of "powerpcel". Since nobody is
using "powerpcel" at this point, it's safe to do so I believe. Thanks!

[Serge Hallyn (serge-hallyn)]

On the qemu-ppc and qemu-devel mailing lists the following query was made about
the non-packaging changes:

> So before we add anything to QEMU, I would like to first see someone
> point me to kernel patches that actually enable LE on Linux for 32bit
> user space. So far I'm not aware of any (and I doubt it makes much sense)

In the original description you had said

> I am in the porting powerpcel (32bit ppc LE) ubuntu 14.04, and got
> successfully chroot with this qemu-ppcle patch and it looks very promising
> (i.e. build perl looks ok)

To be sure I am understanding you right, are you in fact working on the kernel
patches that would be needed for this to be useful?

[Launchpad Janitor (janitor)]

This bug was fixed in the package qemu - 2.1+dfsg-3ubuntu3

---------------
qemu (2.1+dfsg-3ubuntu3) utopic; urgency=medium

  * replace d/p/revert-acpi-table-size-bump with
    pc-reserve-more-memory-for-acpi.patch from upstream
  * debian/binfmt-update-in
    - don't run in a container
    - add ppc64le as target (LP: #1358268)
  * Add experimental ppcle support (LP: #1358268)
 -- Serge Hallyn <email address hidden> Wed, 27 Aug 2014 18:24:32 -0500