On Wed, 16 Jun 2010, Jan Kiszka wrote: > malc wrote: > > On Wed, 16 Jun 2010, Jan Kiszka wrote: > > > >> Jun Koi wrote: > >>> On Wed, Jun 16, 2010 at 4:49 PM, Jan Kiszka <jan.kis...@web.de> wrote: > >>>> Jun Koi wrote: > >>>>> On Wed, Jun 16, 2010 at 4:40 PM, Jan Kiszka <jan.kis...@web.de> wrote: > >>>>>> Jun Koi wrote: > >>>>>>> On Wed, Jun 16, 2010 at 4:07 PM, Alfredo Mungo > >>>>>>> <chimerane...@gmail.com> 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) > >> Both: Neither supports gdb them as part of its register set nor does the > >> remote gdb protocol transport them. > >> > >> You need this for segmented addressing, either in real mode (linear > >> address = segment * 16 + offset) or in segmented protected mode (less > > > > Not true in general (big real mode), CPU still references hidden segment > > cache even when protection is enabled. ^^^^^^^ disabled
> Unfortunately, the BIOS does not start in big real mode e.g... It's actually fortunate since there's no access whatsoever to the cache (on a real system that is) -- mailto:av1...@comtv.ru
