MMU issues with AM335X and 14.05

Martin Stein martin.stein at ...1...
Sun Aug 17 21:27:27 CEST 2014 

Btw. hope you have done 'make clean' after your Makefile changes.
Otherwise this could cause the build system to act strange.

On 17.08.2014 21:16, Martin Stein wrote:
> Hi Bob,
> Looks like there's a problem with the name spaces. Instead of being
> comprised by 'Arm', 'Genode' should be a top-level name space as well
> as 'Kernel'. I think it would be a good idea to investigate why the
> 'Arm' prefix is active at all at 'double_list.h:95'.
>
> Martin
>
> On 17.08.2014 18:57, Bob Stewart wrote:
>> Hi Martin,
>>     Been out-of-town for the past few days.
>>
>> I understand the changes due to issue 1199 and I did create the core
>> library make file (in base-hw/lib/mk/platform_bbb) for the platform
>> I'm working with before I left. Everything built ok until it got to
>> /cpu_session_component.c/ in the core library build section where
>> multiple errors occurred. The following error would indicate I'm
>> missing something fundamental:
>>
>> In file included from
>> /Work/Genode/genode-14.05/repos/base-hw/src/core/kernel/scheduler.h:19:0,
>>                  from
>> /Work/Genode/genode-14.05/repos/base-hw/src/core/kernel/processor.h:21,
>>                  from
>> /Work/Genode/genode-14.05/repos/base-hw/src/core/kernel/thread.h:21,
>>                  from
>> /Work/Genode/genode-14.05/repos/base-hw/src/core/include/platform_thread.h:29,
>>                  from
>> /Work/Genode/genode-14.05/repos/base/src/core/include/cpu_session_component.h:27,
>>                  from
>> /Work/Genode/genode-14.05/repos/base/src/core/cpu_session_component.cc:21:
>> /Work/Genode/genode-14.05/repos/base-hw/src/core/kernel/double_list.h: In
>> member function ???void
>> Arm::Kernel::Double_list<T>::insert_tail(Arm::Kernel::Double_list<T>::Item*)???:
>> /Work/Genode/genode-14.05/repos/base-hw/src/core/kernel/double_list.h:95:4:
>> error: ???printf??? is not a member of ???Arm::Genode???
>>
>>
>> Regarding the page fault in the ROM fs  initialization, I did not
>> isolate the route cause -- it appeared to be getting a low address of
>> 0x1000 and try to create a translation table entry with that. I
>> thought I saw some changes in the ROM area in the pull, so I was
>> going to get a clean build and then try again.
>>
>>     Bob
>>
>>
>> On 08/13/2014 05:12 AM, Martin Stein wrote:
>>> Hey Bob,
>>>
>>> The changes you're talking about originate from this issue:
>>> https://github.com/genodelabs/genode/issues/1199. Core now consists
>>> of a generic 'base-hw/src/core/target.mk' that solely defines the
>>> target name and a dependency to the library 'core'. All the other
>>> content that core is composed of resides in the variant 'core.mk'
>>> and 'core.inc' library-description files within 'base-hw/lib/mk' and
>>> its sub-directories (respectively 'core-*.mk' and 'core-*.inc' for
>>> libraries that are additions to the core library).
>>> At the one hand these changes reduce redundancy and LOC count as
>>> hardware-specifics were split up more fine-grained when transfered
>>> into libraries, at the other hand we unified the scheme of handling
>>> orthogonal specifiers (see for example the core-trustzone* files
>>> that provide optional trustzone support for different platform
>>> specifiers). Apart from that, the commits didn't change that much
>>> regarding the substance of core.
>>> I hope this short insight helps you applying your changes to the
>>> current state. If you have further questions on this don't hesitate
>>> to ask.
>>>
>>> Regarding the page fault: Does that mean that you were able to fix
>>> the fault?
>>>
>>> Cheers
>>> Martin
>>>
>>> On 12.08.2014 23:41, Bob Stewart wrote:
>>>> Martin,
>>>>     Have not been able to build with the pull from the master
>>>> branch. Looks like there are changes to base-hw build that I've not
>>>> seen before.   The platform target.mk file now appear in a
>>>> repos//base-hw/lib/mk/ directory as core.mk. Is there documentation
>>>> on the changes? I searched the git repository but couldn't find any.
>>>>
>>>>
>>>> The mmu faulting address was coming from the creation of
>>>> Rom_modules in the ROM fs.
>>>>
>>>> Thanks,
>>>>         Bob
>>>>
>>>> On 08/11/2014 09:03 AM, Bob Stewart wrote:
>>>>>
>>>>> Thanks for the quick reply, Martin.
>>>>>
>>>>> I'll pull the current master branch tomorrow and let you know if
>>>>> it fixes my issue.
>>>>>
>>>>> Thanks for the debugging tip on core faults.
>>>>> My core-only mmio regions are the same as they were in 14.02 and
>>>>> unless the handling of the region has changed I should have the
>>>>> correct translation table entries. My PDBG output from the
>>>>> _mmu_exception method was:
>>>>>
>>>>> /void Kernel::Thread::_mmu_exception(): f_addr 0x1008 f_writes 0x1
>>>>> f_pd 0x813d6004 f_signal 0x0 label core//
>>>>> /
>>>>> Looks like I've a problem with the fault address, so I'll keep
>>>>> digging to see where that is coming from.
>>>>>
>>>>> Thanks,
>>>>>         Bob
>>>>> On 08/11/2014 07:54 AM, Martin Stein wrote:
>>>>>> Hi Bob,
>>>>>>
>>>>>> On 09.08.2014 22:21, Bob Stewart wrote:
>>>>>>> I went back to the 14.05 issues today and found I could get the kernel 
>>>>>>> initialization to complete successfully if I reverted the S bit to 
>>>>>>> "unshared" in the memory attributes in a Section entry create. Prior to 
>>>>>>> 14.05 this bit was set to "unshared" and was presumably changed in 14.05 
>>>>>>> to allow for multiple processors accessing the same memory regions.
>>>>>> We had an issue (https://github.com/genodelabs/genode/issues/1181)
>>>>>> recently that the shared-bit should be set only when using SMP. The
>>>>>> related changes are in the current state of our master branch
>>>>>> (https://github.com/genodelabs/genode/tree/master) but not in version
>>>>>> 14.05. Could you please give it a try?
>>>>>>
>>>>>>> In addition, after completing kernel initialization, core's "main" 
>>>>>>> function is entered, the info message for creating local services shows 
>>>>>>> up, a translation for the top of RAM (0x80000000) is created, then the 
>>>>>>> message "failed to communicate thread event" occurs and init is never 
>>>>>>> called. Any thoughts on why that message is appearing would be 
>>>>>>> appreciated. It appears to be coming from initialization of the root 
>>>>>>> interfaces.
>>>>>> This seems to be a page fault in core. Normally core should never
>>>>>> trigger a page fault because there's no one to handle it. So the kernel
>>>>>> doesn't know who to inform about it and thus prints this message. To
>>>>>> prevent this situation, memory regions statically needed by core
>>>>>> (program image, MMIO regions) get mapped 1:1 in the 'Core_pd'
>>>>>> constructor in 'base-hw/src/core/kernel/kernel.cc' using, among others,
>>>>>> the platform specific method 'Platform::_core_only_mmio_regions'. I
>>>>>> assume that your port misses a region in this function. You can get
>>>>>> further information about the page fault by printing things like
>>>>>> '_fault_addr', '_fault_writes', 'char const * Thread::label()', and
>>>>>> 'unsigned long Thread::ip' in the method 'Thread::_mmu_exception()' in
>>>>>> 'base-hw/src/core/arm/cpu_support.cc' right before '_fault.submit()'.
>>>>>>
>>>>>> Cheers
>>>>>> Martin
>>>>>>
>>>>>> ------------------------------------------------------------------------------
>>>>>> _______________________________________________
>>>>>> genode-main mailing list
>>>>>> genode-main at lists.sourceforge.net
>>>>>> https://lists.sourceforge.net/lists/listinfo/genode-main
>>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>>
>>>>
>>>> _______________________________________________
>>>> genode-main mailing list
>>>> genode-main at lists.sourceforge.net
>>>> https://lists.sourceforge.net/lists/listinfo/genode-main
>>>
>>>
>>>
>>> ------------------------------------------------------------------------------
>>>
>>>
>>> _______________________________________________
>>> genode-main mailing list
>>> genode-main at lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/genode-main
>>
>>
>>
>> ------------------------------------------------------------------------------
>>
>>
>> _______________________________________________
>> genode-main mailing list
>> genode-main at lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/genode-main
>
>
>
> ------------------------------------------------------------------------------
>
>
> _______________________________________________
> genode-main mailing list
> genode-main at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/genode-main

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.genode.org/pipermail/users/attachments/20140817/b3f96934/attachment.html>

More information about the users mailing list