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RE: CF custom implementation

To: "'Ulrich Eckhardt'" <>,
Subject: RE: CF custom implementation
From: Kiran Thota <>
Date: Fri, 6 May 2005 10:32:40 -0700
Original-recipient: rfc822;
 The ide-patch i took is from
Is that good enough?

Alan was referring to PIO mode in that thread but this implementation doesnt 
have IO mode and also no IDE support. It only has memory mode and I will 
have to support it as memory. How do I do that?

Another question: If I rework the board so that the wires coming to MEMR and 
are rewired to IOR and IOW respectively, does it work in TrueIDE mode? Just a 


-----Original Message-----
[]On Behalf Of Ulrich Eckhardt
Sent: Friday, May 06, 2005 12:14 AM
Subject: Re: CF custom implementation

Kiran Thota wrote:
> I am working on a MIPS-based processor SoC which has a custom CF
> implementation over Local Bus. The CF doesnt support IO mode, interrupts, 
> 32-bit support.
> It has limited register support [no interface registers to reset the CF]. I
> am using 2.6.10 from linux-mips. I have already written a PCMCIA/CF socket
> socket for the same.
> The goal is to use the CF cards as memoy devices. Advise me on the path to
> take:
> PCMCIA/CF ->CS/DS -> IDE [I found a patch to make IDE work in polled mode]

Could you tell me where you found that patch?

> I am currently using Lexar and Hitachi Compact Flash cards.

CF is a standard, so this shouldn't matter.

> The CIS can be read and when the Linux boots up and I invoke cardmgr
> [v3.2.8], it sees the device as ATA/IDE Fixed Disk [Func = 4 (Fixed Disk) ]
> Is there a way to force it to come up in memory only mode? Please suggest.

I'm using a CF card attached to the PCMCIA interface of an Alchemy Au1100. 
Since my board only has a CF slot, I'm not using the whole PCMCIA stack at 
all - CONFIG_PCMCIA=no and no cardmgr. All I do is detect the card, parse the 
CIS and register the CF card with the IDE/ATA system of the kernel, just like 
Alan Cox suggested in the recent thread "ATA devices attached to arbitary 
busses". One good reason for me doing so is that I need to mount the root 
filesystem from the CF but the PCMCIA stack requires user-space helpers.


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