Date: Wed, 30 May 2007 10:55:05 +0200 From: rmgls@wanadoo.fr To: Mike Meyer <mwm@mired.org> Cc: freebsd-hackers@freebsd.org Subject: Re: direct I/O access Message-ID: <20070530085506.163217000088@mwinf2816.orange.fr>
next in thread | raw e-mail | index | archive | help
>> i am trying to port my old assembler soft for Dos to FreeBSD. > >You have my sympathy. > Thanks, i need it, because its a big deal for me! >> i need to write and read directly to the midi and scsi device. >> when i try something like this i receive a sigbus error >> >> SORRY, i am NOT nor a C nor a FreeBSD expert!!! >> all i know is Assembly language! > >You may have to learn some. Or at least be able to read it. > I read C, and begin to write some short examples. but of course my lack is great on this topic. >And I have to ask. The hardware has changed a lot since the days of >DoS, and things that worked then may cause strange results on modern >hardware. Do you know modern hardware, or are you still using dos-era >hardware? > yes i am aware of this, and have a few understanding of protected mode too, also about music softs. ---cut--- >> >> .data >> .align 4 >> params: .word 0x330,2,1 # midi port => enabling IO ??? >> >> .text >> .align 4 >> .global _start >> _start: >> nop >> pushl params >> pushl $0x4 > >I believe this should be $0x4, as you want to *set* the values, not >get them. > is it necessary to restore the permissions on exit? >You also need to open the file "/dev/io". I believe that leaving this >file open for anything more than a handful of instructions would be a >bad thing, but I'm not going to verify it. > i tried this, but without set_ioperm, it was not clear on the doc that one have to use these two funcions: in io man: i find SEE ALSO: i386_get(set)_ioperm... is my understanding correct? thanks a lot raoul
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070530085506.163217000088>