Re: dummy help on io
From: Gene Heskett (gene.heskett_at_verizon.net)
Date: 12/13/04
- Previous message: Zwane Mwaikambo: "Re: dynamic-hz"
- In reply to: Randy.Dunlap: "Re: dummy help on io"
- Next in thread: Randy.Dunlap: "Re: dummy help on io"
- Reply: Randy.Dunlap: "Re: dummy help on io"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
To: linux-kernel@vger.kernel.org Date: Sun, 12 Dec 2004 20:50:34 -0500
On Sunday 12 December 2004 19:11, Randy.Dunlap wrote:
>Gene Heskett wrote:
>> Greetings;
>>
>> I've ordered the device drivers book from O-Reilly but it will be
>> a few days getting here.
>
>Get it online:
>http://lwn.net/Kernel/LDD2/
Thanks, but my printer is down, I mde the mistake of installing
cups-1.1.22. But I'll go get it anyway.
>
>> I'm trying to mod the GPL'd archive PIO.tar.gz, so it will build a
>> driver for a pci card with 3 each 82C55's on it, and I *think* I'd
>> have it working with the first of the 3 chips if I could figure
>> out what to do about using the call "iopl(3);" on installing
>> the driver, and conversely an "iopl(0);" at rmmod time.
>
>Where is that coming from? I don't see it in the tarball
>or the web site (if I'm looking at the right place).
> http://ieee.uow.edu.au/~daniel/software/robotd/
<http://ieee.uow.edu.au/~daniel/software/PIO/>
>> I'm told this is required to gain access perms to addresses above
>> 0x3FF. The call "ioperm" is used below that I've been told.
>
>iopl() and ioperm() are userspace calls that call (g)libc.
>The kernel doesn't call them.
So my driver module does need them?
>> Unforch, an "insmod PIO io=0xf100" (where the card is addressed
>> at currently) is spitting out an "unresolved symbol" error for the
>> iopl call.
>>
>> Being a rank beginner at "pc" hardware, can someone give me a
>> checklist of things I've probably left out please?
>
>Can you put the iopl() call into your app instead?
I can try it in the examples demo.c which I've modified to run
the motor 10 revolutions, if it runs. 1 step/sec. That runs
without any errors *if* I take the iopl() back out of the driver
and insmod it.
>or into a shell script that forks the app (since the iopl
>man page says: Permissions are inherited by fork and exec.)
>
>> Kernel is 2.4.25-adeos. With the module "rtai" inserted when emc
>> is running for realtime control purposes.
>>
>> The card is pure hardware, no bios, only address decoding that
>> can set the base address anyplace in the first 64k of address
>> space in a step of 4 sequence from 0xnn00-0xnn0C for the 4
>> ports of chip 1, 0xnn10-1C for chip 2, etc, where the nn is the
>> dipswitch setting.
-- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) 99.30% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attorneys please note, additions to this message by Gene Heskett are: Copyright 2004 by Maurice Eugene Heskett, all rights reserved. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
- Previous message: Zwane Mwaikambo: "Re: dynamic-hz"
- In reply to: Randy.Dunlap: "Re: dummy help on io"
- Next in thread: Randy.Dunlap: "Re: dummy help on io"
- Reply: Randy.Dunlap: "Re: dummy help on io"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Relevant Pages
|
|
