[vdr] Re: NVRAM WakeUp

[Patrick GUENEAU <pgueneau@wanadoo.fr>]

Hello,

One thing very important is that even if the nvram is altered and the
wakeup scheduled, nothing tells the bios to read this configuration and
do program the RTC.

That the reason why Sergi mentionned that you should reboot once the
BIOS reads the new nvram config and program the RTC.

I tried many things without any success until Sergi annonced his first
release and i have read his comments. 

Maybe there is something like a bios call to enforce reading nvram ; it
seems very strange too that hwclock is able to change the clock without
having to do anything else than writing to nvram.

As the addresses used by hwclock are below the first bytes you can dump
from /dev/nvram, it seems there are other addresses in nvram.
i found that addresses between clock addresses (i.e. bytes 0,2,4 are for
HWCLOCK and 1,3 and 5 for ALARM) should be the right ones to directly
change the wakeup time. I tested a modified hwclock program to dump
alarm time instead of hardware clock and it worked.

Now, i have no real use of programmed wakeup since i moved my main vdr
recording machine directly on the server. So i stop investigating.

just my 2 cents (of EURO ;-) .

Patrick.


Arno Esser wrote:
> 
> Johannes Feigl wrote:
> 
> >>AFAIK, theres no way to do that.
> >>on an AT Mainboard it is _not_ possible.
> >>
> >
> >yes, but i donot mean at-boards ...
> >
> >mfg Johannes
> >
> >
> >
> >
> >
> Based on your hint I tried the real time clock functionality in kernel
> (see linux/Documentation/rtc.txt ). The test programs run very fine, but
> it had no effect on the real time clock alarm settings. In more detail:
> the alarm clock work if I set my computer to suspend mode. There is no
> effect, if I power off my machine. But I thought that would be possible
> with the small nvram utility.
> 
> So my question is can I enhance the rtc functionality to alter the
> values in bios or do I really have to spent hours changing the bios
> settings and investigating this terrible bios hexdump? Any hints on that?
> 
> Gruß Arno