SCSI scanner, sym/ncr driver, pt(4)
matthias.andree at gmx.de
Mon Jan 30 08:38:32 PST 2006
On Mon, 30 Jan 2006, Stefan Esser wrote:
> > > > But I wonder if the ncr(4) driver offered any advantages.
> > >
> > > It doesn't. There used to be a time when it worked with the old 810 and
> > > sym(4) didn't, but this no longer holds.
> Hmmm, this is news to me. That would require the sym driver to contain
> both sets of SCRIPTS code, the one from the NCR driver and the one from
> the sym driver.
The man page sym(4) reads (as of 6-STABLE):
"sym also uses LOAD/STORE SCRIPTS instructions for chips that
support it. Only the early 810, 815 and 825 NCR chips do not
support LOAD/STORE. Use of LOAD/STORE instead of MEMORY MOVE
allows SCRIPTS to access IO registers internal to the chip (no
external PCI cycles). As a result, the driver guarantees that no
PCI self-mastering will occur for chips that support LOAD/STORE."
More information about the freebsd-scsi