From: satoh AT asd DOT tnes DOT nec DOT co DOT jp
Message-Id: <199712090005.JAA12488@asd.tnes.nec.co.jp>
MIME-Version: 1.0
Date: Tue, 09 Dec 1997 09:02:11 +0900
To: djgpp AT delorie DOT com
Subject: Re^2: Physical address of convenstional memory
In-Reply-To: Your message of "Mon, 8 Dec 1997 16:13:13 +0200 (IST)"
 	<Pine DOT SUN DOT 3 DOT 91 DOT 971208161220 DOT 4200Z-100000 AT is>
Precedence: bulk

>>
>>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