freebsd stable - Dec 2004 - hw.ata.ata_dma="0": can I do this during bootup at the

>>>> It would be nice if I can set hw.ata.ata_dma="0" at
the loader
>>>> prompt during bootup, so that the system at least will boot
from
>>>> harddisk. Is that possible?
>>> Yes, that's possible.  Drop the loader to the prompt and do the
>>> following:
>>> set hw.ata.ata_dma=0
>>> boot
>>
>> btw: I have a similar problems, but not with the boot disc, but one of
>> my data drives, thus I want ata_dma enabled for the other discs.
>>
>> I have to dispatch a
>>
>>     atacontrol mode 1 foo UDMA33
>>
>> to set this drive (slave on second controller) to UDMA33 (otherwise it
>> would use UDMA100). But I have to do it before /etc/rc.d/fsck starts
>> accessing the device. Right now I've added above line to the
beginning
>> of aforesaid script.
>> Is there a nicer/better place to tell the kernel (don't like
editing
>> the
>> rc-scripts).
>
> You can use /etc/rc.early for that. You'll have to create it if it
> doesn't yet exist. Put 'atacontrol mode 1 foo UDMA33' in it,
and it
> should execute that command before mounting the drives.
Note that you can put this in loader.conf as well - if you're having 
trouble booting the system to do it, boot to "safe mode" - should get 
you in.

I have an old Aladdin V with a buggy UDMA chipset, and doing this fixed 
the problem rather nicely.

--
Erik Hollensbe <erik@hollensbe.org>

* Erik Hollensbe <erik@hollensbe.org> [041211 16:55]:

Hi Erik,
> > > I have to dispatch a
> > >    atacontrol mode 1 foo UDMA33
> > You can use /etc/rc.early for that. You'll have to create it if it
> > doesn't yet exist. Put 'atacontrol mode 1 foo UDMA33' in
it, and it
> > should execute that command before mounting the drives.
> Note that you can put this in loader.conf as well - if you're having
> trouble booting the system to do it, boot to "safe mode" - should
get
> you in.
are you sure you can call atacontrol(1) from within loader.conf?
I don't want to disable DMA (by setting hw.ata.ata_dma=0), just a slower
DMA mode for a single device. Otherwise the fsck on this device will
fail with read errors.

I will try rc.early, thanks for the suggestion.

Best regards
 Christian

-- 
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