Re: [Qemu-devel] sh4: more patches

[Magnus Damm]

On 6/26/07, Blue Swirl <address@hidden> wrote:
> On 6/22/07, Magnus Damm <address@hidden> wrote:
> > The method used to locate emulation bugs may be of value for other
> > fellow qemu hackers. I've written a small gdb script that single steps
> > in an endless loop dumping registers between each instruction. Then
> > I've used this script on both real target hardware (using gdbserver)
> > and using the gdbstub provided by qemu. Finally the traces have been
> > compared. I have more patches for this if anyone is interested...
>
> I'm interested in the scripts, those could be helpful to get Sparc64
> bugs exterminated.

Ok, to begin with I've attached two patches needed for this to work on
sh4. They are in quite hairy shape and not ready for upstream merge. I
don't plan on submitting them upstream any time in the future - they
are just useful for debugging. Anyway, I suspect you need to implement
something similar for sparc64 as well.

Together with the patches I've attached two gdb scripts.

This is how I generate a trace on the target system:

1. Boot up a recent Linux kernel on your target hardware.
2. Bring up your network interfaces.
3. Disable vma randomization and maybe vdso as well using:
 # echo 0 > /proc/sys/vm/vdso_enabled
 # echo 0 > /proc/sys/kernel/randomize_va_space
4. Start your test program on the target using gdbserver and "env -i":
 # env -i ./gdbserver localhost:1234 test-static-sh4
5. Start cross-gdb on your host and pass the target script:
 $ ./gdb -x gdb-script-target > trace-target
6. Wait until gdb exits, ignore error message

Then I do the same thing on the host using qemu-sh4:

1. Make sure vma randomization is disabled on the host:
 # echo 0 > /proc/sys/kernel/randomize_va_space
2. Start your test program using qemu-sh4 and "env -i"
 $ env -i /path/to/qemu-sh4 -g 1234 test-static-sh4
3. Start cross-gdb on your host and pass the host script:
 $ ./gdb -x gdb-script > trace
4. Wait until gdb exits, ignore error message

Then just diff the two traces! Have fun!

/ magnus

qemu-cvs_20070703-sh4-behave-as-gdbserver.patch
Description: Binary data

qemu-cvs_20070607-sh4-stack-placement-elf-auxv.patch
Description: Binary data

gdb-script
Description: Binary data

gdb-script-target
Description: Binary data