Date: Tue, 19 Nov 1996 23:07:43 +0100 (MET) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Cc: Emmanuel.Duros@sophia.inria.fr Subject: Re: Creating a device driv., Pb with outb, outw... Message-ID: <199611192207.XAA10010@uriah.heep.sax.de> In-Reply-To: <199611191827.TAA18620@chouette.inria.fr> from Emmanuel Duros at "Nov 19, 96 07:27:49 pm"
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As Emmanuel Duros wrote:
> #include<machine/cpufunc.h>
>
> void main(void){
>
> outb( 0x300, 1 );
> }
>
> I always get a BUS ERROR. I also tried on the parallel port (0x378)
> without success.
>
> Any comments on this, why does this happen ?
Because user programs are normally not allowed to fiddle with the
hardware directly; that's the kernel's domain.
You can circumvent this restriction by keeping a descriptor on the
/dev/io ``security hole'' open.
--
cheers, J"org
joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)
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