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RE: [pci] How to hit a pci device in dos enviroment
Dear Darrent:
Well, you have two problems. The first is that in normal DOS environments,
you are in the real mode of the 80x86 processor, where indeed it can only
address 20 lines. DOS itself has an interrupt (INT15) that may be used to
switch in and out of protected mode, but, ... it takes a lot of knowledge to
make it work and a few books including the original IBM-PC technical
reference manual with the BIOS source code.
Modern BIOS implementations switch the processor into protected mode to do
the PCI initialization since PCI did not even exist when the IBM-PC was
first conceived. Windows and Linux operated entirely in protected mode and
as such have access to the entire 32 address space of the microprocessor.
So the short answer is, you will be very frustrated trying to use DOS for
PCI stuff without a lot of knowledge and would be best served by either
using Windows or Linux to get to PCI manipulation. I can tell you that Linux
has a series of utilities, including lspci which is a PCI analog of ls
(that's the unix list command, analogous to dir in DOS) to list the
registers in configuration space and their is a similar command setpci for
setting arbitrary PCI configuration space registers. You might look into
these. There may be Windows equivalents, although I do not use Windows for
embedded work, just Linux and vxWorks.
Charles
-----Original Message-----
From: owner-pci@opencores.org [mailto:owner-pci@opencores.org]On Behalf Of
DARRENTJEN@yeah.net
Sent: Tuesday, August 13, 2002 7:16 PM
To: pci@opencores.org
Subject: [pci] How to hit a pci device in dos enviroment
if I configure the base addr as ffff0000,I can drive addr bus as
ffffXXXX to hit the pci device,but in dos mode,there are only 20 addr
lines,then what addr can be used in a test assemble program to hit the
device?
thx a lot
กกกก
DARRENTJEN@YEAH.NET
2002-08-14
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