Mail Archives: djgpp/1997/12/08/19:02:01
>>
>>On Thu, 4 Dec 1997, Fabrice ILPONSE wrote:
>>
>>> To answer the question, it's very dangerous. As the memory is remap, it
>>> can be swapped to the disk so the information is no more at a physical
>>> adress. First i think the DOS memory have to be locked (i think it's
>>> possible) so the data won't be swapped. This is one point. Now where to
>>> get this adress. Perhaps in the TSS or a V86 structure(if it's not the
>>> same) but i don't know enough to help you about those structures.
>>
>>You don't need to go to these lengths, AFAIK. If the physical address
>>is required for the DMA transfers, then just use whatever
>>`__dpmi_allocate_dos_memory' returned as if it were mapped 1:1.
>>AFAIK, Windows transparently traps all DMA requests and substitutes
>>the actual physical address for the logical one you use. (Otherwise,
>>real-mode DOS programs that use DMA would never work.)
>>
I want to know the physical address for the PCI bus master device.
When using DMA, Windows traps all DMA requests. But what I want to
do is to set physical address to the register of PCI bus master device.
Can Windows traps requests for the PCI bus master?
Thanks in advance.
------------------------- Masayuki Satoh
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