22 Jan
2007
22 Jan
'07
12:10 p.m.
Jules Richardson wrote:
What I'd really like I suppose is a user-space driver for a widget that
provided SCSI and SASI support via a *totally* dumb HBA (i.e. polled I/O and
twiddling of bus lines "directly") - in other words, one step less intelligent
still than most "dumb" HBAs (which still use some sort of SCSI IC). It'd be
slow as molasses, but speed isn't the critical factor compared to flexibility
and ease of driving.
There's no reason you can't do this now using linux (and other *nix's no
doubt).
You just mmap the device space into user space and start poking. You
can't use interrupts but you can poll. And it's not that slow, to be honest.
I do this all the time to debug embedded h/w - sometimes even for
production code if the need is just to wack a few things do something
simple.
and simple 5380 style isa scsi cards 9 (i.e. DTC) are easy to find on ebay.
-brad