and all SCSI devices (except that it's not done quite the way I want). New
information added includes:
- A text description of the device
- A ``state''---unknown, unconfigured, idle, or busy
- A generic parent device (with support in the m.i. code)
- An interrupt mask type field (which will hopefully go away) so that
. ``doconfig'' can be written
This requires a new version of the `lsdev' program as well (next commit).
This puppy is in good shape now.
It is a fully blown SCSI-driver, but it isn't a high performance one. It is
implemented entirely with polled I/O, and is intended to drive CD-ROM's, not
disks and tapes. It will run disks and tapes if asked to, but it isn't a
very good idea to do so. Transfer-rates max out at 600-700 kbyte/sec.
There is one problem: when write-requests get over 8192 bytes, the pseudo-DMA
stalls. This is only a problem if you dd(1) to a raw-device of some kind,
for mounting a disk it is ok. I have circumvented this by disabling the
pseudo-DMA in those cases.
It's very unlikely that I will spend more time on improving the performance
of this driver, it can do what I want it to now: install from a CD-ROM, and I
don't see any benefit in actually adding interrupts to the driver, considering
that performance never will be better than 700 kbyte/sec anyway.
You can install it under 1.1.5 too, by adding the lines to files.i386, your
config-file and copying pas.c and ic/ncr_5380.h over.
I will fix any bugs I can get a handle on.
Poul-Henning
This is the slowest and most stupid of our SCSI-drivers, but it is there
and it works. It has been tested with CD-ROM and disk.
It uses no interrupts, no DMA, just polled I/0.
Transfer-rate is <= 100Kbyte/sec.
If you set the jumpers on the board, you can change the unit-number and
you will be able to have four of these co-exist in one computer, why one
would do that is somewhat unclear though.
If I ever get my hand on the docs for this, I will improve it of course,
but for now we can install and access those CD-ROMs.
Garrett Wollman
Poul-Henning Kamp
David Greenman