other: 0.894
semantic: 0.850
permissions: 0.844
PID: 0.840
device: 0.831
debug: 0.802
vnc: 0.798
performance: 0.783
graphic: 0.767
KVM: 0.765
boot: 0.710
files: 0.692
socket: 0.634
network: 0.551

qemu-m68k-static: illegal instruction ebc0 during debootstrap second stage

Host: Ubuntu Precise amd64
Guest: Debian (ports) sid m68k

$ sudo qemu-debootstrap --no-check-gpg --arch=m68k sid m68k http://ftp.debian-ports.org/debian
I: Running command: debootstrap --arch m68k --foreign --no-check-gpg sid m68k http://ftp.debian-ports.org/debian
[...]
I: Running command: chroot m68k /debootstrap/debootstrap --second-stage
qemu: fatal: Illegal instruction: ebc0 @ f67e5662
D0 = 6ffffef5   A0 = f67fbf58   F0 = 0000000000000000 (           0)
D1 = 0000010a   A1 = 00000000   F1 = 0000000000000000 (           0)
D2 = 0000000f   A2 = 00000000   F2 = 0000000000000000 (           0)
D3 = 00000000   A3 = f67e0000   F3 = 0000000000000000 (           0)
D4 = 00000000   A4 = 00000000   F4 = 0000000000000000 (           0)
D5 = 00000000   A5 = f67fc000   F5 = 0000000000000000 (           0)
D6 = 00000000   A6 = f6fff7cc   F6 = 0000000000000000 (           0)
D7 = 00000000   A7 = f6fff580   F7 = 0000000000000000 (           0)
PC = f67e5662   SR = 0000 ----- FPRESULT =            0
Aborted (core dumped)

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: qemu-user-static 1.0.50-2012.03-0ubuntu2.1
ProcVersionSignature: Ubuntu 3.8.0-33.48~precise1-generic 3.8.13.11
Uname: Linux 3.8.0-33-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Mon Nov 25 16:08:26 2013
Dependencies:
 
InstallationMedia: Ubuntu 12.04.3 LTS "Precise Pangolin" - Release amd64 (20130820.1)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: qemu-linaro
UpgradeStatus: No upgrade log present (probably fresh install)

Version: 1.6.0+dfsg-2ubuntu4

Still present in Trusty.

Ken, is that really a bug in QEMU or is Debian expecting some Motorola 68k CPU rather than the ColdFire MCU QEMU emulates?

ebc0 is a bitfield insn which the coldfire doesn't implement.

Andreas.

-- 
Andreas Schwab, <email address hidden>
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."


"Debian currently runs on the 68020, 68030, 68040 and 68060 processors"
http://www.debian.org/ports/m68k/

From 2006:
https://lists.debian.org/debian-devel-announce/2006/01/msg00005.html

So I really don't know. :-/

Ken,

this is known to currently *not* work. As Andreas has already indirectly explained, qemu does not provide full m68k emulation.

Instead, it supports the reduced m68k instruction set of Motorola's ColdFire CPU only.
If you need a QEMU version with full m68k support, please have a look at Laurent Vivier's github repository [1].

You also shouldn't file bugs which are clearly upstream-related to the Ubuntu bugtracker. Ubuntu doesn't even support m68k but Debian does. Still, we also can't do anything about such bugs in Debian, these belong upstream.

Adrian

> [1] https://github.com/vivier/qemu-m68k

Alright, I have created a page on the Debian Wiki which explains how to properly set up a chroot environment for sbuild/m68k on Debian [1].

With this set up, I was able to increase compile performance dramatically as compared to native m68k hardware or the Aranym Atari m68k emulator.

Enjoy!

Adrian

> [1] https://wiki.debian.org/M68k/sbuildQEMU

Triaging old bug tickets... can you still reproduce this issue with the latest version of QEMU? There should now be support for "normal" 68k CPUs, too...

0xebc0 is "bfexts" with register and is implemented since:

    ac815f46a3 target-m68k: Implement bitfield ops for registers

Available since qemu v2.9.0