BBGW Kernel Panic

[jalexmu...@gmail.com]

I'm encountering a kernel panic when I try to unload the "univ-bbgw" cape from my $SLOTS file. 

My setup is: 

Seeed BeagleBone Green Wireless

Seeed Grove Base Cape for Beaglebone v2.0

bone-debian-8.7-seeed-iot-armhf-2017-03-26-4gb

Here's my terminal output and dmesg of the error: https://gist.github.com/alexmullins/a4f9673b2cb280679b8df11be1f4140f. 

I think this is the relevant part of dmseg: 

[  380.483327] Unable to handle kernel NULL pointer dereference at virtual address 0000000d

[  380.491655] pgd = db5d4000

[  380.494384] [0000000d] *pgd=9b533831, *pte=00000000, *ppte=00000000

[  380.500908] Internal error: Oops: 17 [#1] SMP ARM

I've looked at the univ-bbgw.dts and I don't see anything out of the ordinary there (I'm not great with device trees though).

Also, I'm noticing that the Seeed Grove Base Cape for Beaglebone v2.0 doesn't have a valid EEPROM signature:

[    2.554339] bone_capemgr bone_capemgr: Invalid signature 'ffffffff' at slot 3

Not sure if that could have something to do with this.

Does anyone have any tips on where to go from here?

Thanks,

-Alex

[Robert Nelson]

On Mon, Mar 27, 2017 at 10:58 PM, <jalexmu...@gmail.com> wrote:
>
> I'm encountering a kernel panic when I try to unload the "univ-bbgw" cape
> from my $SLOTS file.
>
> My setup is:
> Seeed BeagleBone Green Wireless
> Seeed Grove Base Cape for Beaglebone v2.0
> bone-debian-8.7-seeed-iot-armhf-2017-03-26-4gb
>
> Here's my terminal output and dmesg of the error:
> https://gist.github.com/alexmullins/a4f9673b2cb280679b8df11be1f4140f.
>
> I think this is the relevant part of dmseg:
>
> [ 380.483327] Unable to handle kernel NULL pointer dereference at virtual
> address 0000000d
> [ 380.491655] pgd = db5d4000
> [ 380.494384] [0000000d] *pgd=9b533831, *pte=00000000, *ppte=00000000
> [ 380.500908] Internal error: Oops: 17 [#1] SMP ARM
>
> I've looked at the univ-bbgw.dts and I don't see anything out of the
> ordinary there (I'm not great with device trees though).

That's normal, removing a cape via slots almost never works..

Instead in /boot/uEnv.txt find the "cape_universal=enable", remove
that and reboot.

> Also, I'm noticing that the Seeed Grove Base Cape for Beaglebone v2.0
> doesn't have a valid EEPROM signature:
>
> [ 2.554339] bone_capemgr bone_capemgr: Invalid signature 'ffffffff' at
> slot 3
>
> Not sure if that could have something to do with this.
>
> Does anyone have any tips on where to go from here?

a custom overlay needs to be written for this cape.

Regards,

--
Robert Nelson
https://rcn-ee.com/

[jalexmu...@gmail.com]

 On Tuesday, March 28, 2017 at 9:06:49 AM UTC-5, RobertCNelson wrote:

On Mon, Mar 27, 2017 at 10:58 PM,  <jalexmu...@gmail.com> wrote:
>
> I'm encountering a kernel panic when I try to unload the "univ-bbgw" cape
> from my $SLOTS file.
>
> My setup is:
> Seeed BeagleBone Green Wireless
> Seeed Grove Base Cape for Beaglebone v2.0
> bone-debian-8.7-seeed-iot-armhf-2017-03-26-4gb
>
> Here's my terminal output and dmesg of the error:
> https://gist.github.com/alexmullins/a4f9673b2cb280679b8df11be1f4140f.
>
> I think this is the relevant part of dmseg:
>
> [  380.483327] Unable to handle kernel NULL pointer dereference at virtual
> address 0000000d
> [  380.491655] pgd = db5d4000
> [  380.494384] [0000000d] *pgd=9b533831, *pte=00000000, *ppte=00000000
> [  380.500908] Internal error: Oops: 17 [#1] SMP ARM
>
> I've looked at the univ-bbgw.dts and I don't see anything out of the
> ordinary there (I'm not great with device trees though).

That's normal, removing a cape via slots almost never works..

Instead in /boot/uEnv.txt find the "cape_universal=enable", remove
that and reboot.

 

Is the 'univ-bbgw' loaded on boot when cape_universal=enable? I ask because I 

only see it in my $SLOTS file after I mess around with a few pins. 

 

> Also, I'm noticing that the Seeed Grove Base Cape for Beaglebone v2.0
> doesn't have a valid EEPROM signature:
>
> [    2.554339] bone_capemgr bone_capemgr: Invalid signature 'ffffffff' at
> slot 3
>
> Not sure if that could have something to do with this.
>
> Does anyone have any tips on where to go from here?

a custom overlay needs to be written for this cape.

 

Everything seems to work fine with the 'univ-bbgw' overlay so I'll let it be for now.

Thanks RCN!