From: Juergen Keil <jk@tools.de>
To: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] IDE busmaster DMA support
Date: Fri, 30 Sep 2005 14:04:45 +0200 (CEST) [thread overview]
Message-ID: <200509301204.j8UC4jK0026786@imap3.tools.intra> (raw)
> I'm trying to write an IDE driver with busmaster DMA support.
> My problem is that I can't get the right controller registers addresses.
>
> In the IDE BusMaster DMA specification :
>
> "The control registers for the controller are allocated via the
> devices Base Address register at offset 0x20 in PCI configuration
> space."
>
> If I read the word at offset 0x20 in the PCI configuration space, I get
> 0xc001. But if I boot qemu with a linux live-cd, it tells me that BM-DMA
> is at 0xc000
>
> Do I have to init the PCI IDE controller or something ?
Bit 0 encodes if the registers are in IO (1) or in memory (0) space.
You get the IO base address by using a 0xfffffffe mask.
For memory space the mask is 0xfffffff0, the low four bits encode
a few memory properties (prefetch, 32-bit vs. 64-bit memory addresses).
See the PCI spec for more details. Or for example the PCI_BASE_* defines here:
http://cvs.opensolaris.org/source/xref/usr/src/uts/common/sys/pci.h#519
next reply other threads:[~2005-09-30 12:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-30 12:04 Juergen Keil [this message]
2005-09-30 13:00 ` [Qemu-devel] IDE busmaster DMA support GaLi
-- strict thread matches above, loose matches on Subject: below --
2005-09-30 10:15 GaLi
2005-09-30 11:17 ` Hetz Ben Hamo
2005-09-30 12:20 ` GaLi
2005-09-30 15:16 ` Lennert Buytenhek
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