Re: [Qemu-devel] [Bug 1156313] [NEW] X86-64 flags handling broken

[Torbjorn Granlund <tg@gmplib.org>]

Peter Maydell <peter.maydell@linaro.org> writes:

  On 25 March 2013 14:06, Torbjorn Granlund <tg@gmplib.org> wrote:
  > Still qemu-system-mips64, qemu-system-mips64el, and qemu-system-arm
  > give spurious errors.
  
  If you can provide a reasonably sized test case for
  qemu-system-arm I can investigate that one.
  
I don't know how to make a nice bug report about instability.  Here is
my best effort:

A Debian install, adding the packages gcc, g++, m4, and make, then
downloading GMP (e.g., the latest release) then attempt a GMP build:

     configure && make

This will fail most of the time and in non-reproducible ways.

Last night's build give a segfault and an illop in sh during configure:

http://gmplib.org/devel/testmachines/build/failure/army.gmplib.org:standard.txt

This is certainly not GMP-related, since it is (1) during build and (2)
non-reproducible.

What a "Debian install" means is of course quite unclear.  It is a
fiddly process with many dead ends, not helped by misleading and
incomplete instructions with dead links on the Net.  And passing any
-cpu option to qemu typically leads to early hangs.

I followed Aurélien Jarno's instructions (unfortunately with many dead
links) at http://www.aurel32.net/info/debian_arm_qemu.php, then managed
a painful upgrade route from there to a less obsolete system.  The
upgrade is painful because so many things that ought to work just causes
non-boot.  The newest Debian-packaged kernel that I lastly managed to
make work at all with qemu was "3.0.0-1".

I boot the instable system using this qemu command:

qemu-system-arm -M versatilepb -m 256 \
  -net nic -net tap \
  -kernel vmlinuz-3.0.0-1-versatile -initrd initrd.img-3.0.0-1-versatile \
  -hda arm.img -append "root=/dev/sda1" \
  -display vnc=localhost:30

(Note that my interest is not in playing with qemu testing and compiling
custom kernels.  My interest is improving the test environment for GMP.
Since qemu is very fragile, where the many options are a veritable
minefield, finding some setup which both installs and then boots is very
time consuming.  I tried a fresh install now, to create something more
obviously reproducible, before sending this message, but I didn't manage
to navigate through the minefield today, and have now run out of time.
My working install of arm is not new, and upgrading it also hits mines.
Sorry about that.)

-- 
Torbjörn