January-31st-2020, 02:49 PM
(January-31st-2020, 09:01 AM)Armin@netPI Wrote: Hi Roy,
oh did not know your are using your own SD card.
What I can tell you about the RT kernel patch is that the general patch has to fit to the used kernel. We are using kernel 4.9 with the RT patch and it worked fine. Then we have started a project later using kernel 4.14 and wanted to integrate the very same RT patch and it failed cause it produced 30% CPU load basically and this was unacceptable for us
1. copying the FAT32 partition is not enough. netPI SD card has 4 partitions. You can see them if you mount the SD card in Ubuntu for example. All 4 partitions are needed
2. yes the only chance I see is to build your own RT patched kernel yourself and make your own tests and collect experience like we did with kernel 4.14. I know currently the raspbian kernel is 4.19. I cannot tell you if there is patch available for kernel 4.19. In general we do not share our yocto reciept, but I thought building an own kernel along with any linux is well documented on the web? Isn't it? The landing page is this one here https://wiki.linuxfoundation.org/realtime/start
Thx
Armin
Hi Armin,
I am still contemplating what approach to take.
a. use your kernel and try to change the rootfs in the /boot/config.txt to have my own rootfs + copying the kernel modules from your img to mine.
b. start from clean rpi image
my concerns regarding approach a.
* is the yocto rootfs visible or encrypted ?
* read in another thread in the forum there is some kind of hw id validation https://forum.hilscher.com/Thread-SOLVED...cher-Image
my concerns regarding approach b.
* will I be able to have all net pi hw capability with raspberian vanilla image ?
I took the same sd card that was running with nethat moved it to netPi removed the Firmware packages and Drivers of netHat, installed the netPi Firmware packages and Drivers and tried to compile and run the example you provided. got a message the /dev/spi is missing.
There was a gap in between the Firmware sample and what was extracted from the deb package. R160D000.nxf in deb package, X070D000.nxf in sample. is it just a remains of old version ?
I need also to consider what approach to take in order to be able to move to rt_preemptive patch later on.
I prefer approach b. but I am not sure I will be able to interact with all the hw drivers you provide on netPi. do you use drivers that I have to take from your propitiatory kernel or I can get it done straight forward in a clean image ?
please advice.
Thx
Roy
