Creating a port for vxWorks posed some problems. This port may help as a starting point for similar ports to real-time OS's and other embeddable kernels, particularly where main() is not allowed, and where the configure scripts need to be altered.
I decided to do as little invasive surgery as possible on the NTP code, so I brought the vxWorks header tree in line with the standard unix tree. The following changes were needed, as a side effect these changes will allow for easy porting of other autoconfigure enabled code.
Where I have 386 you will need to put in your target type. The vxWorks tree entry point is /usr/wind.
export CC="cc386 -nostdlib -m486 -DCPU=I80486 -I/usr/wind/target/h"
ln -s ../signal.h
ln -s ../time.h
ln -s socket.h sockio.h
ln -s ../selectLib.h select.h
ln -s ../timers.h
touch file.h param.h resource.h utsname.h var.h ../netdb.h ../a.out.h ../termios.h
echo " ******ADD #include \"sys/times.h\" to sys/time.h "
The configure script must be changed in the following way to get the
linking tests to work, once in the correct directory issue the following
sed -e 's%main.*()%vxmain()%' configure > configure.vxnew
mv configure.vxnew configure
chmod 755 configure
The configure.in file needed to be altered to allow for a host-target configuration to take place.
Unfortunately I have had to make use of the ntp_machine.h file to add in the checks that would have been checked at linking stage by autoconf, a better method should be devised.
Unfortunately there are still quite a few SYS_VXWORKS type defines in the source, but I have eliminated as many as possible. You have the choice of using the usrtime.a library avaliable from the vxworks archives or forgoing adjtime() and using the clock_[get|set]time().The ntp_machine.h file clearly marks how to do this.
You will need autoconf and automake ... available free from the gnu archives worldwide.
The variable arch is the target architecture (e.g. i486)
mkdir A.vxworks (or whatever....)
../configure --target=arch-wrs-vxworks [any other options]
The program should proceed to compile without problem. The daemon ntpd, ntpdate, ntptrace, ntpdc, ntpq programs and of course the libraries are all fully ported. The other utilities are not, but they should be easy to port.
Load in the various files, call them in the normal vxWorks function type manner. Here are some examples. Refer to the man pages for further information.
ld < ntpdate/ntpdate
ld < ntpd/ntpd
ld < ntptrace/ntptrace
ld < ntpq/ntpq
ld < ntpdc/ntpdc
ntpdate ("-b", "192.168.0.245")
sp(ntpd, "-c", "/export/home/casey/ntp/ntp.conf")
ntpdc("-c", "monlist", "192.168.0.244")
ntpq("-c", "peers", "192.168.0.244")
Should you happen across any bugs, please let me know, or better yet fix them and submit a patch. CCII Systems (Pty) Ltd, my employers, have sponsored the time to this port, we would be quite willing to negotiate to do further work. Please let me know how it goes, I would be most interested in offsets and configurations.