[769] in linux-scsi channel archive
SCSI scanner project
daemon@ATHENA.MIT.EDU (Eric Youngdale)
Mon Nov 6 02:51:24 1995
Date: Sun, 5 Nov 95 22:37 EST
From: eric@aib.com (Eric Youngdale)
To: Kenneth Stailey <kstailey@owl.dol-esa.gov>
CC: linux-scsi@vger.rutgers.edu
>In any case, I would like to write a Linux implementation of the
>driver, but I have been hampered by the lack of documentation on how
>to write a Linux device driver for a target-mode peripheral.
OK, if you need any help, give a holler. I expect that this
would be a character device and not a block device. One of the things
you will have to be careful about is that the driver has to obtain
buffers for the I/O that is suitable for DMA for whatever low-level
card you are using. For some cards, there are effectively no
limitations (i.e. PCI cards), and for others, you can only use memory
that lies below 16Mb. I don't know at what level other platforms deal
with this sort of thing, but under linux it is the high level
(i.e. disk, tape, scanner) driver that must do the right thing.
You undoubtably have to deal with this if you support any other i386
platforms.
-Eric
