hw.ata.ata_dma="0": can I do this during bootup at the loader prompt?

[Scott Long]

Rob wrote:
> 
> Hi,
> 
> In /boot/loader.conf, I have
>   hw.ata.ata_dma="0"
> to prevent a WRITE_DMA failure crash at bootup.
> Unfortunately, this forces my UDMA100 harddisk to operate
> at PIO4 speed.
> 
> There are patches flying around on this mailing list that might
> solve the problem. I'm very keen on testing such patches, but I
> should remove the line in loader.conf. However, if the patch does
> not work, I end up with an unbootable disk.
> 
> 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

Scott