Re: bus dma: a flag/quirk for page zero

>> At the very least, require bounce buffers.
>
> Not sure if I got this suggestion in this terse form.
> Could you please explain?

Physical address zero can be DMA'd, but via bounce buffers.
bcopy from address zero up through a pagesize to a bounce buffer, do the 
dma from there (read case), write case the opposite order