[1519] in linux-scsi channel archive
Re: Please, SYMBIOS version question (ncr53c815)
daemon@ATHENA.MIT.EDU (Gerard Roudier)
Wed Mar 5 17:35:26 1997
Date: Wed, 5 Mar 1997 23:28:53 +0000 (GMT)
From: Gerard Roudier <groudier@club-internet.fr>
To: "Francisco J. Montilla" <pacopepe@nova.es>
cc: linux-scsi@vger.rutgers.edu
In-Reply-To: <Pine.LNX.3.95.970305050551.855D-100000@raudo.insflug.org>
On Wed, 5 Mar 1997, Francisco J. Montilla wrote:
> I have the NCR Fast SCSI II 53c815 controller, with SYMBIOS Bios
> version 3.0.x ; I've seen there's a new version (4.0.x), and have read on
> its documentation not to use it with OS/2.
>
> Will the Gerard Roudier driver benefit from upgrading to this
> BIOS?
Boot programs do not make difference among actual disk adapter
used, so they need a OS/independant driver to be present somewhere
in the memory of the machine. This driver is a BIOS.
You need the SDMS BIOS if you want to boot a system from the
SETUP program of your mother board or from most boot managers.
LILO for example needs SDMS BIOS in order to be able to boot from disks
driven by NCR53C8XX based scsi controllers (except Tekram boards which
use a proprietary BIOS).
Once Linux is booted, the SDMS BIOS becomes useless. The ncr driver
performs all necessary initialisations and then drives directly the scsi
controller.
So, the driver will not benefit from upgrading to BIOS 4.0.
> Also, I'm using Gerard's driver version 18, and the led question
> isn't so clear to me. Does the card have conectors for a controller led?
> What's what the led feature provide support for?
The led question is not clear at all.
I would be surprised your board does not have led connector.
The SYMBIOS NCR53C8XX chips provide 5 general purpose IO pins that can
be used for vendor specific features (GPIO0 to GPIO4).
Genuine SYMBIOS boards uses GPIO0 for led support.
- GPIO0 = 0 --> LED ON
- GPIO0 = 1 --> LED OFF
The SDMS BIOS from SYMBIOS has been written for SYMBIOS boards.
So, we can assume (has been checked) that it drives GPIO0 for switching
the LED.
However, some 53C8XX based scsi boards use SDMS BIOS but have the LED
connected to some SCSI signal (scsi busy for example) by some special
logic. Such boards does not need GPIO0 for LED support, but this
features cannot break anything since the SDMS BIOS uses it.
My experience and knowledge about LED support is the following:
- My Dell Omniplex with on-board ncr53c810 at work uses GPIO0 for LED.
- My Promise SCSI Ultra (53C875) uses GPIO0 for LED.
- My ASUS SC200 does not use GPIO0 for LED, but works with SDMS BIOS.
Enabling LED support from GPIO0 is useless but does not break anything.
- SYMBIOS boards use GPIO0 for LED.
- Tekram 390 53C8XX based boards use special logic from SCSI BUSY signal
for LED.
They use a proprietary BIOS and do not like SDMS BIOS in some cases
since GPIO wiring is very specific and may cause trouble with SDMS BIOS.
In order to check if your board need LED support from GPIO0, you
should perform the following tests:
1 - Connect a LED to the controller. Polarity is important to not kill
the LED.
2 - Check the LED works when SDMS BIOS is scanning devices at start-up.
3 - Boot Linux+ncr53c8xx driver with the following setup command:
ncr53c8xx=led:n
If the led stays black, then goto 4, otherwise LED support by the
driver is useless but not dangerous at all.
4 - Boot again with the following boot setup command:
ncr53c8xx=led:y
The led should work now.
Gerard.
