I'm working with an EBSA-285 evaluation board [SA-110 "StrongARM" CPU w/
21285 core logic chip], and am currently running Linux version 2.4.0-test8
as the OS. The board is configured for "host bridge" [a.k.a., "central
function"] mode -- i.e., it is acting as the host bridge for the system.
None of the boards in the system have a hardware clock on them; so there's
no "built in" hardware clock that Linux can use to set/sync the system
clock. The EBSA-285 platform is connected to an isolated (no Internet
access) LAN via a 3Com NIC. The other hosts on the LAN are standard PCs
running both Win2K and Linux (various kernel versions). The EBSA-285 board
uses 'bootp' to obtain its IP address and then 'tftp' to download a
compressed kernel image from one of the Linux hosts on the LAN. The kernel
then uses an NFS mount point as the EBSA's root file system.
Here's the problem: Once each day, Linux on the EBSA-285 resets the system
clock back to the epoch date -- i.e., Jan 1, 1970. My guess is that the
kernel is attempting to update the system clock based on the hardware clock,
and since there is no hardware clock, the kernel simply resets the system
clock to the epoch date/time. As you can probably imagine, this is causing
all sorts of problems for programs that rely on time/date information.
Short of using something like NTP -- which seems excessively complex for
this situation -- is there any other way to sync the system clock on the
EBSA with a clock on one of the Win2K / Linux hosts on the LAN? Ideally, I'd
like the EBSA's linux kernel to obtain the hardware (or even system) clock
time from one of the other Linux hosts on the LAN, and then to use that
date/time info to update the EBSA's system clock date/time [kind-of a
virtual hardware clock]. [FWIW, I don't have the 'difftime' utility working
yet on the EBSA-285 platform.] Any suggestions, pointers to FAQs, HOWTOs,
etc., would be appreciated...
Jim Fischer
CPE/MSEE Grad Student
Cal Poly, SLO
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