Re: [Qemu-devel] Re: PC traces from QEMU

["andrzej zaborowski" <balrog@zabor.org>]

On 29/03/07, Stuart Brady <sdbrady@ntlworld.com> wrote:
> On Thu, Mar 29, 2007 at 08:29:03PM +0300, Antti P Miettinen wrote:
> > "Shashidhar Mysore" <shashimc@gmail.com> writes:
> > > I intend to extract program counter streams from QEMU as a program executes.
> > > Can you please point me to the hooks that I may have to insert into the QEMU
> > > source code in order to extract the PC values?
> >
> > I used to do that with qemu 0.7. I did not dig into this deep enough
> > to find the minimal changes but at least the following was enough:
> [...]
> > - force dc->jmp_opt to zero in target-i386/translate.c
>
> I don't quite see where you would do this.
>
> BTW, the approach I took was to add something like gen_op_dump_pc(s->pc)
> near the top of disas_insn (in translate.c), and have op_dump_pc (in
> op.c) pass the program counter (held in PARAM1) to a helper (in
> helper.c) that then prints it out.  I expect that's not the best
> approach, but it worked quite well for my purposes.

The approach I took was call "cpu_single_step(env, 1); vm_start();
return;" in gdb_vm_stopped in gdbstub.c. Then after I connect to qemu
with gdb the first time it single steps in a loop - probably very
inefficient but works.

Just my two cents.
Andrzej