Re: [Qemu-devel] add debugger command

[Stefan Weil]

Am 28.12.2011 07:35, schrieb Peter Cheung:
> Dear All
> Please take a look http://peter-bochs.googlecode.com , I am an
> operating system developer, bochs has a great build in command-line
> debugger, but it is not good enough for normal use, so I created
> peter-bochs for it. But bochs has a deadly weak point, it runs very
> slow. So I want to add debugger feature for qemu. To let peter-bochs
> works with qemu, need to add these to qemu
> 1) able to let peter-bochs pause qemu during running. In bochs,
> peter-bochs just sending a "ctrl-c" command to bochs, then it pause.
> 2) magic breakpoint, in bochs, when bochs execute a intstruction xchg
> bx,bx, it will pause
> 3) able to send debug command to qemu, through pipeline/socket/whatever.
>
> Is QEMU a tai wan project? I am living in hong kong.
>
> Thanks
> from Peter
>

Hello Peter,

QEMU is not a national project. The QEMU contributors and users
are living all over the world. See http://www.ohloh.net/p/qemu/map.

QEMU has no built-in debugger, but it supports the GDB remote protocol
which allows remote debugging via TCP socket, for example. See
http://sourceware.org/gdb/onlinedocs/gdb/Remote-Debugging.html and
http://sourceware.org/gdb/onlinedocs/gdb/Remote-Protocol.html
for more information on this protocol and
http://qemu.weilnetz.de/qemu-doc.html#gdb_005fusage for instructions
how to use this remote debugging feature with QEMU.

So it should be possible to attach you Java application to QEMU
without any changes of the QEMU source code. All you have to do
is extend your application to support the GDB remote protocol.
There are other graphical debugging front ends (for example DDD
or Insight) which work like this.

Please note that QEMU is not limited to 80x86 emulation. Any
debugging interface must be able to support all QEMU emulation
targets.

Regards,
Stefan Weil