[ntp:questions] Building FreeBSD V8.0 kernel for PPS

unruh unruh at wormhole.physics.ubc.ca
Wed Apr 14 15:19:52 UTC 2010

On 2010-04-14, David J Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
>> Hi all again.
>> I'm still trying to follow the instructions at:-
>> http://blog.doylenet.net/?p=145
> []
>> I did have to go back into sysinstall, to download and install the
>> system sources, but after that, right up to the make buildkernel....
>> command, all had gone as described.
>> So, what's missing, and where how can I get it.
>> Anyone here know what went wrong, or do I go looking for a newbie
>> friendly f'bsd group (not found one of those yet.)
>> Cheers.
>> Dave B.
> Dave,
> Sorry to hear you're having problems.  Those instructions had worked for 
> me.  IIRC, I had downloaded the "kernel developer" set of files when 
> installing FreeBSD.  Perhaps you're missing a compiler or a linker?

I am still confused as to why people recompile their kernel to put in
the kernel PPS. Just use the regular ntp devices like shm and a program
like gpsd to run pps from userland. I have no idea what advantages the
kernel PPS provides, certainly considering the pain of recompiling the
kernel. In fact I would argue that userland is the place where you
should be doing the PPS shaping-- throwing out popcorn spikes, making
sure that the PPS is producing sensible output (eg each pulse coming one
second after the previous on, not 3ms, or something like that, which can

Ie, you do not need kernel pps to make use of pps. 
> To get a log of the session, you could login remotely over SSH.  Enable 
>   http://nixcraft.com/all-about-freebsd-openbsd-netbsd/505-enable-ssh-service-bsd.html
> and then see:
>   http://www.scriptinstallation.in/freebsd_permitrootlogin.html
> I use the TeraTerm Pro (free) Windows terminal emulator with this SSH 
> add-on:
>   http://web.archive.org/web/20050702021104/http://www.zip.com.au/~roca/ttssh.html
> At least you can the cut-and-paste the last few lines with the error.
> Cheers,
> David
>   http://hp.vector.co.jp/authors/VA002416/teraterm.html 

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