Debian Stretch Main: Questions

darethehair · February 28, 2018

BACKGROUND: Back on June 27th, I posted my questions regarding my wish to have certain kernel features activated (or not) by default in the Armbian/Debian kernels of the time -- specifically since I wanted to activate 'PPS' features in order to build a Stratum 1 GPS/PPS timeserver:

Kernel Option Requests?

Here are the 'old' instructions that I used back in June:

ORANGE PI PLUS H3 with GPS/PPS

I ended up needing to install VirtualBox with an Ubuntu 16.04 environment, and successfully created what I needed (i.e. 3.4.113-PPS-sun8i). I was also eager to create a much newer kernel, but that failed (i.e. 4.11.5). My Orange Pi PC Plus is successfully running at this much older 'legacy' kernel version my GPS/PPS NTP timeserver -- and nothing else.

TODAY: I also have a Raspberry Pi 2 running Debian Stretch with FlightAware aircraft tracking. I had been recently forced to upgrade my system from Jessie to Stretch, and basically had to start all over again. It also runs a GPS/PPS timeserver -- and was much easier to implement since no kernel re-compilation was needed.

FUTURE: I would like to *combine* a regular/standard Debian Stretch environment (running FlightAware) *and* a GPS/PPS NTP timeserver on my Orange Pi PC Plus (instead of my Raspberry Pi 2). However, the name/arrangement of the kernel options I think I need (PPS/PTP/Tick-based) have changed locations in the 'make' process. Not only that, but it appears to me that the options that I want are now *default* in the kernel (!). Is this true? Here are the menu options I pick and see:

Select what to build
    Full OS image for flashing
Select the kernel configuration
    Show a kernel configuration menu before compilation
Select the target board.  Displaying:
- Officially supported boards
    orangepipcplus H3 quad core 1GB RAM WiFi eMMC
Select the target kernel branch
Exact kernel versions depend on selected board
    next Mainline (@kernel.org) (4.x)
Select the target OS release
    stretch Debian 9 Stretch
Select the target image type
    Image with console interface (server)

Device Drivers  --->
-*- PPS support  --->
--- PPS support
[ ]   PPS debugging messages
*** PPS clients support ***
< >   Kernel timer client (Testing client, use for debug)
< >   PPS line discipline
< >   Parallel port PPS client
<M>   PPS client using GPIO
*** PPS generators support ***             

Device Drivers  --->
<*> PTP clock support
< > Driver for the National Semiconductor DP83640 PHYTER

General setup  --->
CPU/Task time and stats accounting  --->
Cputime accounting (Simple tick based cputime accounting)  --->
(X) Simple tick based cputime accounting
( ) Full dynticks CPU time accounting

I definitely need 'PPS' stuff, but the kernel option seems to show it is 'default' now. I don't think I need 'PTP', but it also seems to be default. Finally, I am supposed to disable a 'tickless' kernel, and a 'tick' one also seems to be the default (?).

With this in mind, can I just take one of recent nightly Armbian/Debian Stretch images and forget about kernel compiling from now on e.g. Armbian_5.38_Orangepipcplus_Debian_stretch_next_4.14.14? Are these images supposed to be ones that boot and run successfully -- or are they totally hit-and-miss and at-my-own risk? If they are not 'safe', then what are my options for the creation of a Debian Stretch environment that will support my desired uses and configuration?

Thanks for any confirmation/advise you can give me -- I have been using Linux for many years -- and built my own kernels years ago -- but this is a whole new level of learning and complexity for me to understand

Dare

P.S. Does '4.x' imply Debian Stretch? If so, what is the difference between:

default Vendor provided / legacy (3.4.x - 4.4.x)
next Mainline (@kernel.org) (4.x)
dev Development version (4.x)

I am assuming that what I want is the middle one i.e. "next Mainline (@kernel.org) (4.x)"

Edited February 28, 2018 by darethehair
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Strontium · February 28, 2018

I don't know the exact answer to your question, but i do know that stretch will only build with the Mainline kernel or the Dev one. If you choose "legacy" and then try and build a stretch image it will object. At least for Allwinner H2/H3.

darethehair · April 25, 2018

UPDATE: Yesterday I (finally) got my 2nd Orange Pi PC Plus, and proceeded to install the latest Ambian 'mainline' image onto it:

Armbian_5.38_Orangepipcplus_Debian_stretch_next_4.14.14.img

My goal (as mentioned above) was to avoid -- if at all possible -- the need to re-compile the kernel in order to enable PPS for GPS accurate time tracking. From using 'armbian-config, I was easily able to do two things that I think were needed (and which were then added to '/boot/armbianEnv.txt':

overlays=pps-gpio uart3

I wired up a GPS module, rebooted, managed to get GPSD working, but the PPS stuff doesn't (yet) seem to be according to 'dmesg':

[    8.283951] pps-gpio pps@0: failed to map GPIO to IRQ: -22
[    8.283978] pps-gpio: probe of pps@0 failed with error -22

I also notice that ''/dev/pps0' is not present, so 'ppstest' won't work either.

Any advise on what to do next? Do I have to edit/recompile a 'device tree' or something like that? There is a hint way back in 2016 that it might be required: