Re: RFC: outb 0x80 in inb_p, outb_p harmful on some modern AMD64with MCP51 laptops

[H. Peter Anvin]

David P. Reed wrote:
> I do remind all that 0x80 is a BIOS-specific standard, and is per BIOS - 
> other ports have been used in the history of the IBM PC family by some 
> vendors, and some machines have used it for DMA port mapping!!

Correction: ALL machines use it for DMA port mapping.  The port is 
assigned to the legacy DMA controller, but performs no operation. 
That's what makes it safe to write (NOT read!)

	-hpa
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