RE: [9fans] Replacing 9load

["Nigel Roles" <nigel@9fs.org>]

> kuroneko  the sym53cxxx comment came from the fact that if you
>          don't link in the sym53cxxx detection support into
>          9load and then boot a kenfs kernel, kenfs does not
>          see the 53cxxx [similarly, 9load also detonates violently if
>          you have a 53c810, 825 or 815 without SCRIPTS support]
>          somebody has updated the 53cxxx driver at some point,
>          and its definately not particularly friendly now
>          I'm pretty sure when I looked at the 2e 53cxxx driver,
>          it wasn't dependant on SCRIPTS

SCRIPTS is the name of the language used to program the SCSI sequencer
(specialised instruction set microprocessor if you like). It's possible that
it can also be used to name the sequencer itself. One thing for sure; all
53c8xx devices (including 10, 15, 25) all support it. It is a fundamental
feature of the entire chip range, and what distinguishes it from the earlier
53c7xx series.

Therefore I struggle to understand what not having SCRIPTS support means.

Now, it is just about possible to perform SCSI I/O without using the
sequencer, as the registers can be operated on directly; I guess this would
mean a driver which did not use SCRIPTS. Very early Lunix drivers for the
53c810 used it in this legacy mode, driven by modified 53c7xx drivers, but
even before the first Plan 9 driver was written, this approach was already
deprecated and NetBSD and Linux had SCRIPTS based drivers. The author of the
Plan 9 driver followed this approach.

Russ is also correct in his comments that the driver works on other
architectures; at one time it worked on a BeBox.