Setting the time

Samuel Greenfeld greenfeld at
Mon Aug 27 10:05:25 EDT 2012

If anti-theft is used with delegated leases (so the school server can give
leases for a few weeks at a time), the XOs will trust a signed timestamp
provided from the school server.   However olpc-update-query will only
reset the XO's clock if it is off by more than a day.

According to a comment in the code this is done to avoid messing with NTP,
except our OS builds don't currently have NTP in them.

School servers run NTP servers which NTP clients can connect to.  These are
not currently configured to support running without an external NTP source,
although they can be configured to do so.

If a locally accurate clock at the XS site is required and Internet is not
available, NTP can use a cheap USB or serial GPS unit as a time source.
Running gpsd or similar may be required depending on the GPS's supported

In any case if OLPC or Sugarlabs wants to formally integrate NTP services
into our products, we should be polite and ask if we need our
own vendor subdomain.  These allow the NTP pool to shut off misbehaving
clients without affecting other users, and Fedora and CentOS already have
their own.

On Mon, Aug 27, 2012 at 9:39 AM, Tony Anderson <tony_anderson at>wrote:

> Hi,
> In a school deployment, it is desirable that all of the XOs have the same
> time. This time should be synchronized with/by the school server (even if
> the school server is wrong). It is not reasonable to base this capability
> on access to the internet.
> Casio sells 'atomic' watches that synchronize to Ft. Collins by radio.
> Neat, but how does this work in Rwanda?
> Tony
> On 08/27/2012 03:19 PM, devel-request at wrote:
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>> Today's Topics:
>>     1. Re: Impossible to set date in 11.3.0? (James Cameron)
>>     2. Re: Firmware issu (Kevin Gordon)
>>     3. Re: Firmware issu (Kevin Gordon)
>>     4. Re: Impossible to set date in 11.3.0? (Kevin Gordon)
>> ------------------------------**------------------------------**
>> ----------
>> Message: 1
>> Date: Mon, 27 Aug 2012 18:43:39 +1000
>> From: James Cameron<quozl at>
>> To: devel at
>> Subject: Re: Impossible to set date in 11.3.0?
>> Message-ID:<20120827084339.**GH7830 at<20120827084339.GH7830 at>
>> >
>> Content-Type: text/plain; charset=us-ascii
>> On Sat, Aug 25, 2012 at 01:07:35PM -0400, Samuel Greenfeld wrote:
>>> To the best of my knowledge this is an intentional omission for
>>> antitheft reasons.  Instructions on how to set the clock from OFW or
>>> the command line are at**Clock<>.
>> I think the task of setting the clock should be split from the
>> problems that lead to it described in that page.  It is far too scary
>> looking.
>>  If using the "date" command is not sufficient to permanently store
>>> the change, "hwclock --systohc" or similar may also need to be used.
>> "date" followed by a successful normal shutdown should work, because a
>> normal shutdown runs hwclock ... but "hwclock --systohc" is handy in
>> case you aren't sure that a normal shutdown will happen next.
>>  In newer firmware builds (potentially newer than 11.3.0's), Open
>>> Firmware can log into a Open, WEP, or WPA-PSK secured access point
>>> and use NTP to set the time.  To do this use the "essid" command
>>> followed by the actual ESSID to set the ESSID, "wep" or "wpa" to set
>>> the password, and "ntp-set-clock" (without any parameters) to query
>>> a server from the public NTP pool and get the current time.
>> The firmware included with 11.3.0 can already do ntp-set-clock with
>> open wireless access points and USB Ethernet adapters.  More recent
>> firmware fixed WEP and WPA-PSK, if I recall correctly.
>> (Nothing to do with WEP and WPA-PSK in Linux though, you can stay on
>> older firmware for that.)
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