mint-aware HD driver

[Claus Brod <clausb@hpbeo79.bbn.hp.com>]

> I was thinking about the problems with interrupt driven HD drivers,
> that cause mint not to block while doing disk access.
> One problem is that we would need a kind of semaphore for the dma hardware
> as it has to be locked against duplicate accesses at the same time.

This is not a problem at all if we have a general /dev/scsi driver.
In this case, any process that wants to access SCSI hardware
directly would Fopen() that driver, and MiNT could apply its
usual restrictions against multiple access. We don't need semaphores
if there is only *one* official SCSI driver. Such a driver should,
however, probably have a Fcntl() mode to query its status, i.e. if
the SCSI channel is currently used by it.

> What do you think about it?

I think this is one of the less important problems. It's much more
important to have a reentrant GEMDOS, or else the whole project
comes to a grinding halt. That's exactly the point where my own driver
currently is. I haven't found the time yet to implement such a thing
in the MiNT kernel myself.

--clausb@hpbeo79.bbn.hp.com-----------------------------------------------
Claus Brod, MDD, HP Boeblingen      Magic is real unless declared integer.
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