[PATCH v6 0/3] AArch64: KGDB support

[Vijay Kilari]

On Tue, Jan 7, 2014 at 5:41 PM, Catalin Marinas <catalin.marinas at arm.com> wrote:
> On Mon, Jan 06, 2014 at 06:12:01PM +0000, Will Deacon wrote:
>> On Thu, Dec 19, 2013 at 11:50:48AM +0000, vijay.kilari at gmail.com wrote:
>> > From: Vijaya Kumar K <Vijaya.Kumar at caviumnetworks.com>
>> >
>> > Based on the step-handler and break-handler hooks patch from
>> > Sandeepa, KGDB debugging support is added for EL1
>> > debug in AArch64 mode. Any updates that come for Patch 1 from
>> > Sandeepa will be rebased in next version
>> >
>> > With second patch,register layout is updated to be inline with GDB tool.
>> > Basic GDB connection, break point set/clear and info commands
>> > are supported except step/next debugging
>> >
>> > With third patch, step/next debugging support is added, where in
>> > pc is updated to point to the instruction to be stepped and
>> > stopped.
>> >
>> > With fourth patch, the compile time breakpoint instruction
>> > reordering is fixed by making kgbd_breakpoint() as noinline
>> >
>> > Tested with ARM64 simulator
>> >
>> > v6:
>> >  - Change pstate register to 8 bytes to make endian nuetral.
>> >    Use GDB below GDB patch to display pstate in Big endian mode.
>> >    https://sourceware.org/ml/gdb-patches/2013-12/msg00720.html
>> >    Thanks to Andrew.
>>
>> Thanks for getting this new version out. Just a few things before it can be
>> applied:
>>
>>   1. Can you please use "arm64:" instead of "AArch64:" in the patch
>>      subjects?
>>
      OK.

>>   2. Can you get an ack from somebody like Jason on the final patch please?
>>
      I have not received any ack from Jason.

>>   3. Can you rebase onto the for-next/core branch at the arm64 repo:
>>
>>        git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
>>
>>      you'll get a trivial conflict against arch/arm64/kernel/Makefile.
>
> Just to be clear here, I would only recommend rebasing on top of this
> branch if there are patches queued for upstream which are required by
> the rebased patches and there isn't a topic branch already elsewhere. I
> do *not* recommend this branch for any kind of development (though
> testing is fine and we can fix the trivial Makefile conflicts
> ourselves).

OK. I will rebased on top of that branch and resend the patches soon.

>
>>   4. Can you make sure that the gdb patch you linked to actually gets
>>      merged? There is still some discussion by the looks of it.
>
> I guess the kernel patches will have to wait for the binutils patch to
> go in. BTW, does this mean that kgdb on arm64 will only work with a
> future version of gdb?
>
KGDB works with current gdb version as well, except that it only fails
to display
cpsr reg value if kernel is built in BE mode. In LE it works fine.

> --
> Catalin