RCOutputAioPRU.cpp:SIGBUS error generated

[Knaldgas]

Hi @imfatant Thanks for providing this guide, it's exactly what we need. I have BeagleBone Blue, flashed it with the image linked on the guide. I have updated the kernel:

/opt/scripts/tools/update_kernel.sh --lts-4_19 --bone-rt-channel

Besides some complaining about locale and falling back to "C", all seems good.

I have compiled and installed ardupilot as described (build on the board, took a few hours :)). Running every command in /usr/bin/ardupilot/aphw works fine. Running ardurover (as root) fails with:

scan:688: scan past end of eeprom
scan:688: scan past end of eeprom
RCOutputAioPRU.cpp:SIGBUS error generated

Running any other, e.g. arduplane (as root) fails with:

RCOutputAioPRU.cpp:SIGBUS error generated

dmesg returns the following after each attempt:

[ 1345.051433] Unhandled fault: external abort on non-linefetch (0x1818) at 0xb6fe4000
[ 1345.051449] pgd = 3e454bc4
[ 1345.051453] [b6fe4000] *pgd=9ae23831, *pte=4a324343, *ppte=4a324833

Right now the service is disabled, and I'm running the commands manually. I've not yet started on Part 3 (peripherals), as the service didn't want to start.

I've read through the other issues, and searched google, but haven't found a solution yet.

I've been through the guide a couple of times, and I can't see what I've missed. Any hints?

~Per

[imfatant]

There are a couple of things to try, and I'll be updating the guide accordingly tonight or tomorrow. Here's a preview:

1) In /boot/uEnv.txt: Ensure that the line uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-14-TI-00A0.dtbo is commented out thus: #uboot_overlay_pru=/lib/firmware/AM335X-PRU-RPROC-4-14-TI-00A0.dtbo Next, uncomment the line #uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo so that it reads uboot_overlay_pru=/lib/firmware/AM335X-PRU-UIO-00A0.dtbo. Reboot. Then, type lsmod | grep pru Hopefully, you'll see: uio_pruss 16384 0 uio 20480 2 uio_pruss,uio_pdrv_genirq

2) There seems to be an issue with the onboard eMMC, perhaps because people are trying to burn too large an image onto it (although the image you create by STRICTLY following the guide should fit). Nevertheless, for now, you can force the BBBlue always to boot from the SD card, but we're going to do this by intentionally corrupting the boot sector of the eMMC. BACK UP ANY IMPORTANT DATA ON THE eMMC BEFORE DOING THIS sudo dd if=/dev/zero of=/dev/mmcblk1 bs=1M count=10

Hope these steps solve your problem.

-- Imf

[Knaldgas]

Thanks! - Step 1 was exactly the issue - ardurover now starts. It still writes:

scan:688: scan past end of eeprom
scan:688: scan past end of eeprom

but it starts :)

Can we safely ignore those two complaints? We're running without SDCard - Is that ok?

~Per

[imfatant]

Yes, that's all normal. You can run with or without the SD Card. The important thing NOT to do is:

1. Boot off the SD Card.
2. Peform the steps in the guide (including expanding the partition with /opt/scripts/tools/grow_partition.sh).
3. Install lots of extra stuff onto this partition.
4. Try to flash the lot to the eMMC by uncommenting cmdline=init=/g' in /boot/uEnv.txt.

If there's too much data, this appears to cause a problem. I don't have the time or inclination right now to find out exactly why...

:)

[Knaldgas]

Until now I have always flashed the eMMC directly from the downloaded image, and then started updating directly on the eMMC, so we are fine - Thanks! :-)

[swissembedded]

for me it has been 1) and 2), had to add entry in /etc/modules to load uio_pruss and erase flash.