Re: ISA DMA take 2

Adrian Cox [off-list ref] wrote:

Attached is an update to my ISA DMA patch. The main change from the
previous patch is that it works, because it now changes MAX_DMA_ADDRESS.
I've tested it on my platform (Via 686 southbridge, ISA DMA for floppy),

                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

and it shouldn't break any others.

What's your memory map? Do you put the bottom 16 MB of main memory in the
bottom 16 MB of the PCI memory space on the PCI segment with the Via without an
I/O hole?

MS

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Michael Sokolov wrote:

What's your memory map? Do you put the bottom 16 MB of main memory in the
bottom 16 MB of the PCI memory space on the PCI segment with the Via without an
I/O hole?

Yes - and I set ISA_DMA_THRESHOLD to 0x00ffffff. It's not possible to
use ISA DMA with the Via southbridge unless you have main memory at 0x0
on the PCI bus.

Of course, if anybody knows a cheap southbridge with 32-bit ISA DMA,
UDMA100, and maybe USB, it would be nice to hear of it for future boards.

--
Adrian Cox   http://www.humboldt.co.uk/


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