[Qemu-devel] Re: [Bug 581353] Re: qemu doesn't stop execution upon hitting a breakpoint

[Jun Koi]

On Wed, Jun 16, 2010 at 4:49 PM, Jan Kiszka <address@hidden> wrote:
> Jun Koi wrote:
>> On Wed, Jun 16, 2010 at 4:40 PM, Jan Kiszka <address@hidden> wrote:
>>> Jun Koi wrote:
>>>> On Wed, Jun 16, 2010 at 4:07 PM, Alfredo Mungo <address@hidden> wrote:
>>>>> Same thing happens to me, same versions as above.. I must turn to
>>>>> another app to accomplish my work while awaiting for a bug-fix, the code
>>>>> is perfectly executed but while gdb hits the breakpoints qemu goes on..
>>>>>
>>>>> --
>>>>> qemu doesn't stop execution upon hitting a breakpoint
>>>>> https://bugs.launchpad.net/bugs/581353
>>>>> You received this bug notification because you are a member of qemu-
>>>>> devel-ml, which is subscribed to QEMU.
>>>> i think this bug has been fixed in 0.12.4. have you tried that??
>>> Or this is a well-known gdb deficit: if the bootloader operates in
>>> real-mode, you have to set two breakpoints, one at the linear address to
>>> make qemu catch it, and another one at the segment offset to avoid gdb
>>> skipping the exit due to ip != bp-addr.
>>>
>>> gdb is still fairly restricted when it comes to system-level debugging,
>>> specifically as it lacks support for special x86 registers and the
>>> segmented addressing mode.
>>
>> what do you mean by "it lacks support for special x86 registers" ?
>
> idtr, gdtr, ldtr, tr, crX - to name the most important ones.

do you mean gdb has no command to show the values of these registers?
or you mean it doenst have anyway to get notified when these registers
are modified? (i dont see how this is useful for debugging, anway)

thanks,
J