NTP and uClibc

Carmelo AMOROSO carmelo.amoroso at st.com
Mon Jul 20 13:38:35 UTC 2009


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Mike Frysinger wrote:
> On Thursday 04 December 2008 17:52:33 Michael Deutschmann wrote:
>> One of the new configure options in uClibc-0.9.30, UCLIBC_NTP_LEGACY,
>> controls the ntp_gettime() and ntp_adjtime() calls, which are only used by
>> the NTP daemon.
>>
>> You should be aware that stock ntp-4.2.4p5, the current version, will in
>> fact not compile on uClibc no matter how that flag is set.
>>
>>
>> The problem is that ntp requires the call "__adjtimex".  If __adjtimex is
>> not detected, the "tickadj" utility will fail to build on Linux.  (It
>> falls back to a hack it uses on non-Linux kernels, and uClibc doesn't
>> supply the headers it would need for that.)
>>
>> uClibc has "adjtimex", which has identical semantics (so far as I know),
>> but NTP and its configure script won't use that.  The two underscores are
>> mandatory.  So to get ntpd to work on uClibc, I have to supply a shim
>> library that translates __adjtimex() to adjtimex().
>>
>> The good news is that if __adjtimex() is available, NTP can be fully
>> functional without the ntp_???time() calls.
>>
>>
>> So, in the next version of uClibc, I recommend changing "adjtimex" to
>> "__adjtimex", and removing the ntp_???time calls entirely.
> 
> upstream ntp has a bug report already:
> https://support.ntp.org/bugs/show_bug.cgi?id=769
> -mike

ntp could also be configured with --disable-tickadj

but ntp must be fixed with this patch. Indeed since 4.2.4p7
it seems that is not possible to configure it any more.


- -------------
Do not unset the ac_cv_make_tickadj variable allowing to use
the cached value as defined during the configure with --disable-tickadj
option, that is used with uclibc system due to lack of support.
This does not affect glibc system anyway.

Signed-off-by: Fabio Arnone <fabio.arnone at st.com>
Signed-off-by: Carmelo Amoroso <carmelo.amoroso at st.com>

- --- ntp-4.2.4p7/configure.orig  2009-05-28 11:19:09.000000000 +0200
+++ ntp-4.2.4p7/configure   2009-05-28 11:19:25.000000000 +0200
@@ -44789,7 +44789,7 @@ esac
 # be better to simply remove the hunk above, I did not want
 # to remove it if there is hope it will be used again.
 #
- -unset ac_cv_make_tickadj
+# unset ac_cv_make_tickadj

 echo "$as_me:$LINENO: checking if we want and can make the tickadj utility" >&5
 echo $ECHO_N "checking if we want and can make the tickadj utility... $ECHO_C" >&6

> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> uClibc mailing list
> uClibc at uclibc.org
> http://lists.busybox.net/mailman/listinfo/uclibc

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)
Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org

iEYEARECAAYFAkpkc1sACgkQoRq/3BrK1s+wTwCg/UXdEkFya8A7pezZfRlMubMZ
BoMAoNNiKHThQDZXq4cabzhUmWYO86rc
=LZKu
-----END PGP SIGNATURE-----


More information about the uClibc mailing list