direct I/O access
rmgls at wanadoo.fr
rmgls at wanadoo.fr
Wed May 30 08:55:08 UTC 2007
>> 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
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