Re: [poky] [PATCH] initscripts: added save-rtc to runlevel S

Re: [poky] [PATCH] initscripts: added save-rtc to runlevel S

[ChenQi]

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-------- Original Message --------
Subject: 	Re: [poky] [PATCH] initscripts: added save-rtc to runlevel S
Date: 	Thu, 10 Jan 2013 11:20:16 -0800
From: 	Felipe Ferreri Tonello <eu@felipetonello.com>
To: 	ChenQi <Qi.Chen@windriver.com>



Chen

Can you please send this email to the mailing list, so we can discuss there?

Thank you,
Felipe

On 01/09/2013 06:23 PM, ChenQi wrote:
> On 01/10/2013 01:57 AM, Felipe Ferreri Tonello wrote:
>> Hi Chen,
>>
>> Thank you for your answer.
>>
>> On 01/09/2013 12:16 AM, ChenQi wrote:
>>> On 01/09/2013 01:35 PM, Felipe Ferreri Tonello wrote:
>>>> Hi Chen,
>>>>
>>>> On 01/08/2013 06:16 PM, ChenQi wrote:
>>>>> On 01/09/2013 08:18 AM, eu@felipetonello.com wrote:
>>>>>> From: "Felipe F. Tonello" <ftonello@cercacor.com>
>>>>>>
>>>>>> It is necessary to add save-rtc.sh to runlevel S so the system is
>>>>>> updated when
>>>>>> it boots up.
>>>>> Hi ftonello,
>>>>> What do you mean by "system is updated"?
>>>> I meant system clock.
>>>>
>>>> What is happening now is that when you turn off the device, without
>>>> system halt, the next time the device is booted up the system clock is
>>>> not in sync with the rtc.
>>> Hi Felipe,
>>>
>>> I'm sorry, but I really don't see why this patch works.
>>> Below is my understanding for the system clock, hardware clock and
>>> /etc/timestamp.
>>> (The file name 'save-rtc.sh' is somewhat misleading, 'save-timestamp.sh'
>>> would be a more reasonable one.)
>>>
>>> /etc/timestamp is used to provide a reasonable reference for system
>>> time.
>>> The initial contents in this file is the building time of the image.
>>>
>>> The system clock should always be in sync with the rtc as long as the
>>> /etc/init.d/hwclock.sh is present, whose main purpose is to sync system
>>> clock and hardware clock.
>>> No matter whether the system is shutdown normally or crashes, the system
>>> clock is according to the hardware clock by hwclock.sh.
>>
>> Is there anything special to enable hwclock.sh?
>>
> In the current project, hwclock.sh is invoked in bootmisc.sh if
> /etc/init.d/hwclock.sh exists.
>
> Although there are symlinks in /etc/rc[2345].d/ like "Sxxhwclock.sh ->
> ../init.d/hwclock.sh", they have no real effect! This is a bug scheduled
> to be solved. For more details, refer to
> https://bugzilla.yoctoproject.org/show_bug.cgi?id=3612.
>
> For a temporary workaround, change the link names from 'hwclock.sh' to
> 'hwclock'.
>
> This bug will be solved soon :)
>
> Cheers,
> Chen Qi
>
>> I understand what you say, but here that patch was the only way to
>> have system clock (down to minutes, also, or even seconds, don't
>> recall) sync up with the rtc.
>>
>> Btw, this patch I did few months ago. So I don't remember exactly what
>> was happening.
>>
>> Do you know by the top of your mind how is this process? Because, as I
>> remember, save-rtc.sh was never been called. I'm not sure.
>
>>
>> Felipe
>>
>




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