Subject: Re: Patch: Generic TODR for ARM ports
To: Garrett D'Amore <garrett_damore@tadpole.com>
From: Garrett D'Amore <garrett_damore@tadpole.com>
List: port-hpcarm
Date: 09/17/2006 09:33:20
Garrett D'Amore wrote:
> Valeriy E. Ushakov wrote:
>   
>> On Sun, Sep 17, 2006 at 16:46:32 +0200, Peter Postma wrote:
>>
>>   
>>     
>>> I can add an RTC driver, but I'm not sure how useful that would be,
>>> the RTC value is invalid at boot-time
>>>     
>>>       
>> hpcboot passes current time to the kernel as part of bootinfo.  It
>> will be off by several seconds by the time the kernel starts, but
>> that's still better than fs time.
>>
>> BTW, why is RTC time invalid?
>>
>> SY, Uwe
>>   
>>     
>
> If you read the messages, you will find out that the problem is that no
> RTC driver is registered with the MI todr code.  It is likely that this
> could be solved by adding an RTC driver which just uses the boot-info time.
>
> Alternatively, for a port which gets the time passed in bootinfo, I can
> see a case being made for #ifdef'ing out the warning messages in
> kern_todr.c.   Please not that this case is very different from assuming
> an NFS root mount is current -- one is probably a good assumption, while
> the other might not be.
>
>   

Actually, if we have the bootinfo written to the RTC by machdep code,
then a driver could pick it up using the "normal" NetBSD way of things,
and this would be best.

I.e. we need to bits of code: 1) an RTC driver, 2) code in mach_init or
somesuch to "prime" the RTC from bootinfo.

-- 
Garrett D'Amore, Principal Software Engineer
Tadpole Computer / Computing Technologies Division,
General Dynamics C4 Systems
http://www.tadpolecomputer.com/
Phone: 951 325-2134  Fax: 951 325-2191