Raspberry Pi test report

[Christian Mauderer]

Does the same error occur on the Pi2 Qemu? In that case you could use it
for proper debugging.

On 21/01/2020 03:35, Alan Cudmore wrote:
> I don't really have a debug setup.. I'm just using printk for now. But
> I have a pretty efficient setup where I can add a few printk
> statements, rebuild and copy the smp01.exe sample over to the SD card.
> I use this board:
> https://www.adafruit.com/product/3589
> It lets me connect the serial port using a USB cable, and it also
> supplies power and provides a switch. I can pop the SD card in, flip
> the switch and watch the UART output.
> (Edit, make, objcopy, move card to pi, and flip the power switch).
> The board provides plenty of power for the single core models through
> the host USB port. I should double check that it's providing enough
> power for the Pi2 before I spend too much time!
> 
> Here is an example of my latest output where the SMP initialization is
> not completing:
> RTEMS RPi 2B 1.1 (1GB) [00a21041]
> in _SMP_Handler_initialize
> in _SMP_Handler_initialize, max processors = 4
> in _SMP_Handler_initialize - calling _CPU_SMP_Initialize
> in _CPU_SMP_Initialize
> in _SMP_Handler_initialize - _SMP_Processor_maximum = 4
> in _SMP_Handler_initialize - calling _SMP_Start_processors
> In _SMP_Start_processors
> In _SMP_Start_processors - index = 0
> In _SMP_Start_processors - index = 1
> In _SMP_Start_processors - calling _CPU_SMP_Start_processor
> in _CPU_SMP_Start_processor
> in _CPU_SMP_Start_processor - wait for secondary processor to complete
> in Per_CPU_State_wait_for_non_initial_state
>  CPU state = 0
> in Per_CPU_State_wait_for_non_initial_state - about to call
> _CPU_SMP_Processor_event_receive in while loop
> in Per_CPU_State_wait_for_non_initial_state - after
> _CPU_SMP_Processor_event_receive in while loop
>  CPU state  after = 0
> in Per_CPU_State_wait_for_non_initial_state - about to call
> _CPU_SMP_Processor_event_receive in while loop
> 
> 
> Alan
> 
> On Mon, Jan 20, 2020 at 9:03 PM Niteesh <gsnb.gn at gmail.com> wrote:
>>
>> What is your debugging setup? It would be really helpful for my future works on Rpi3.
>>
>> Thanks,
>> Niteesh
>>
>> On Tue, 21 Jan, 2020, 7:23 AM Alan Cudmore, <alan.cudmore at gmail.com> wrote:
>>>
>>> A little more information on my Raspberry Pi 2 SMP tests:
>>>
>>> The BSP startup is getting to this loop:
>>> https://git.rtems.org/rtems/tree/cpukit/score/src/percpustatewait.c#n49
>>> (In the function _Per_CPU_State_wait_for_non_initial_state)
>>> In the while loop on line 49, the CPU state is PER_CPU_STATE_INITIAL (0).
>>> The while loop calls _CPU_SMP_Processor_event_receive() and returns,
>>> but the state is still 0
>>> It calls _CPU_SMP_Processor_event_receive() again and does not return.
>>>
>>> I'm reading up on the defines in percpu.h (comments for the defines
>>> are very helpful by the way)
>>> Based on what I can tell in the comments, the boot CPU will wait in
>>> PER_CPU_STATE_INITIAL
>>> until the secondary processors complete their primary initialization
>>> and transition to
>>> PER_CPU_STATE_READY_TO_START_MULTITASKING.
>>>
>>> Next is to figure out why the secondary processors are not
>>> transitioning or possibly why events are not occurring?
>>>
>>> Alan
>>>
>>> On Mon, Jan 20, 2020 at 6:25 PM Chris Johns <chrisj at rtems.org> wrote:
>>>>
>>>> On 21/1/20 10:20 am, Alan Cudmore wrote:
>>>>> As it turns out the latest RTEMS master may need some of the dtb
>>>>> and/or overlay files in the raspberry pi SD card. But the updated
>>>>> instructions that Niteesh submitted for the raspberrypi BSP should
>>>>> still be valid.
>>>>
>>>> Great.
>>>>
>>>>> Either way, we should be able to automate it. A firmware release on
>>>>> Github is ~180 megabytes. If you clone the whole repository, it's 10+
>>>>> Gigabytes, probably because you get every binary release.
>>>>
>>>> Ouch. If we list the needed files, even if there is a few, I can fetch them from
>>>> github and avoid a full clone. We would need to settle on a specific hash or
>>>> version but that is not a bad thing.
>>>>
>>>>> I'm trying to troubleshoot the RPi 2 SMP a little bit now. Non SMP
>>>>> code seems to work on the Pi 2, but when you have an example with
>>>>> #define CONFIGURE_MAXIMUM_PROCESSORS 4
>>>>> it crashes during initialization.
>>>>
>>>> Awesome and all the best. I am sure you will figure it out.
>>>>
>>>> Chris
>