[Qemu-devel] Bugs

[Qemu-devel] Bugs

[malc]

Following is the list of some easy to reproduce bugs in QEMU,
perhaps someone will have motivation to fix them:

Preliminary:

cvs -d :ext:anoncvs@subversions.gnu.org:/cvsroot/qemu login
cvs -d :ext:anoncvs@subversions.gnu.org:/cvsroot/qemu co qemu
cd qemu
./configure --target-list=i386-softmmu
make

======================================================================
DR-DOS EMS

Steps:
$ wget http://www.boblycat.org/~malc/drdos.fda.bz2
$ bunzip2 drdos.fda.bz2
$ i386-softmmu/qemu -L pc-bios -fda drdos.fda

[enter]
[enter]
C:\>wrms

Under other circumstances (without EMS driver, or on MS-DOS 6.2 with
or without EMS driver) this thing should just print an error message
and exit. With DR-DOSes EMS driver it enters endless exception loop.

This issue probably will arise for many non trivial DOS4G/W programs.

======================================================================
Hard Rox demo

Steps:
$ wget http://www.boblycat.org/~malc/rox.hda.bz2
$ bunzip2 rox.hda.bz2
$ i386-softmmu/qemu -L pc-bios -hda rox.hda

[enter]
[enter]
C:\>cd rox
C:\ROX>rox

Again an endless do_interrupt loop but this time it's more severe
since QEMU never gets around of checking SDL event queue and GUI
window is unkillable (by normal means). I would guess it's some
sort of MMU emulation fault.

This issue probably will arise for many non trivial go32 programs.

======================================================================
ReactOS floppy

Steps:
Obtain live CD from:
http://prdownloads.sourceforge.net/reactos/reactos0.2.6-REL-live.zip?download

$ unzip reactos0.2.6-REL-live.zip
$ ./qemu-img create test.fda 1440K
$ gdb --args i386-softmmu/qemu -L pc-bios -cdrom roslive.iso -fda test.fda

Navigate to Start -> Run. In the dialog type: cmd

[Make sure to ungrab the mouse]

C:\reactos>a:

0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0x0804b727 in qemu_run_timers (ptimer_head=0x8106440, current_time=The value of variable 'current_time' is distributed across several
locations, and GDB cannot access its value.

) at /mnt/big/npf/cvs/qemu/qemu-vanilla/vl.c:760
#2  0x0804dbd0 in main_loop_wait (timeout=0) at /mnt/big/npf/cvs/qemu/qemu-vanilla/vl.c:2742
#3  0x0804dcd5 in main_loop () at /mnt/big/npf/cvs/qemu/qemu-vanilla/vl.c:2787
#4  0x0804f33a in main (argc=9, argv=0xbfffefb4) at /mnt/big/npf/cvs/qemu/qemu-vanilla/vl.c:3820

With some other QEMU builds (different build options and so on) i get
different back-traces. Something is really fishy here, as if QEMU
manages to really screw up memory in host space. I was getting
segfaults in code_mem_writel and free.

--
mailto:malc@pulsesoft.com

[Qemu-devel] Bugs

[James Jacobs]

> Using the start.bat file included with the QEMU package (except changing
> cd-rom and hard disk image filenames as appropriate).
> I haven't adjusted any audio settings, I'm using whatever the defaults
are.

which package ?

0.90 has the imagefile bug, so I normally use 0.82 instead

>Not many solutions here. Could be 32 bits related issues, because in my
case I usually use it in XP host, and I do compile my own binaries...

I suggest doing some testing under Win98SE. I'm willing to do this as long
as a reasonable effort gets made to fix reported bugs.

>I find strange even knoppix does not work with raw images. Have you
tried "fdisk" inside the guest ? and what "dmesg | grep hda" gives you ?

It doesn't even get that far. I get this kind of error: "qemu: could not
open hard disk image 'c:\e2\linux\debian.img'" and QEMU then quits. FILEMON
is showing that the file is being opened read-only for some reason, and the
resultcode is shown as SHARING.

Re: [Qemu-devel] Bugs

[Christian MICHON]

On 3/31/07, James Jacobs <jrj76@optusnet.com.au> wrote:
>
> > Using the start.bat file included with the QEMU package (except changing
> > cd-rom and hard disk image filenames as appropriate).
> > I haven't adjusted any audio settings, I'm using whatever the defaults
> are.
>
> which package ?

you mentionned a package. not me.
did you download the zip containing win32 executables ?

> >I find strange even knoppix does not work with raw images. Have you
> tried "fdisk" inside the guest ? and what "dmesg | grep hda" gives you ?
>
> It doesn't even get that far. I get this kind of error: "qemu: could not
> open hard disk image 'c:\e2\linux\debian.img'" and QEMU then quits. FILEMON
> is showing that the file is being opened read-only for some reason, and the
> resultcode is shown as SHARING.

I'll be offline for a week: send the start.bat to the list, hopefully someone
will look into it.

--
Christian