Showroom USI example: parallel port

Hannes Mayer h.mayer at
Mon Oct 11 21:58:04 CEST 2004

Hi Paolo!

It works!!! :-)))

For some reason ioperm always fails, but iopl(3); seems to succeed!

I'm not sure what you mean with the following statements:

> In any case you should reread what I told, i.e working with LXRT does 
> not mean you cannot do it in kernel space.

Sure, I could do it in kernel space aswell, but I thought the big
advantage of LXRT is to avoid kernel modules and therefore ease development ?

> So if you want to have your parallel port handler in kernel space work 
> as usual but do use the LXRT scheduler always.

I'm planning to have my par-port interrupt capture module in kernel space
and a user-space process for reading the data from a FIFO or shared memory
and write that data to disk. (alpha version without writing data to the
disk is already working)
But if I want to do disk I/O I cannot be in hard real time via LXRT, can I ?

Thank you very much!

Best regards,

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