Messages in this thread | | | From | Gene Heskett <> | Subject | Re: dummy help on io | 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/
| |