Re: Crazy P5GD1 Problem

Neal Lavon wrote:
> I've been posting on the Asus support page about this and have gotten
> some advice but I thought I would try here as well.
>
> I have a P5GD1 installed. The problem is the DVD writer and CD-ROM. I
> have a Plextor DVD writer and a vanilla CD-ROM chained to the Primary
> RAID Connector (red on the motherboard). When the board starts up, the
> IDE scan seems them on Drive 0 and 1 respectively. They show up
> perfectly in Windows XP.
>
> The Primary RAID Connector is set to Standard IDE in the BIOS (V. 1007).
> But the BIOS does not see the CD-ROM or DVD writer at all. When I try to
> boot from the CD-ROM it does not show up on the boot menu, even hitting
> F8 at logo; Smart Boot Manager does not see it, and DOS boot disks do
> not see it.
>
> I think I have everything configured correctly in the BIOS so why can't
> it see the DVD. I guess I'll go check the jumpers to make sure they are
> correct but I believe they are.
>
> Any ideas on how to get them recognized in the BIOS?
>
> Thanks!
>
> Neal Lavon
> Takoma Park, MD
> USA

Is "Interrupt 19 capture" enabled in the BIOS ? You need that to
allow INT 0x13 from a foreign storage controller, that will be using
its own BIOS module.

What you have to remember about BIOS designs, is there are many
many thumbs in the pie. The customer (that's you) thinks the BIOS
is a monolithic piece of code (like every line of source code
is sitting on some Asus guy's disk drive) and can be changed
willy nilly. It doesn't work that way. Many companies contribute
a piece to the puzzle. Certain parts of the hardware are
tightly integrated into the BIOS design, and other parts are
not. When bugs are found in some of the code, Asus has to
report it to a third party, to get it fixed. Then test the
resulting code module when it is delivered.

The Northbridge and Southbridge are treated with the most respect.
The Southbridge storage ports are integrated into the main BIOS
code. They have the ability to have custom settings applied to them
(Auto, LBA, CHS or whatever). Drives on the Southbridge, are
"detected" by the main BIOS module, and you see them in a list as
the BIOS starts.

When a separate controller, like the 8212F is included, the company
making that chip donates a BIOS code module. It is kept separate
from the main BIOS. One software interface between that module
and the main BIOS, is the INT 0x13 (13 hexidecimal equals 19 decimal)
call. It is a standardized way, for a foreign BIOS module, to
register the availability of storage devices for stuff like
read operations (i.e. booting). So the 8212F code module, has
to be able to announce it is present, in order for any connected
devices to be registered.

Asus won't have source for the 8212F code module. The guys at
ITE.com.tw will write that module. As errors are detected, they
will issue updates. Asus will drag their heels, before changing
the 8212F module in a BIOS update. So it takes a long time for
bug fixes to propagate to an end user. (Which is why, back in
the day, some people with Nforce2 boards, were patching their
own SIL3112 code modules, to try to fix a bug they thought they
had.)

If a foreign BIOS module, like the code for the 8212F is enabled,
you should see a separate screen display where the 8212F code
"detects" drives. If you are seeing that, then there must be a code
module present for the 8212F. If "Interrupt 19 Capture" is enabled,
then something may show up as bootable.

A separate function, is the RAID setup screen, which you'd use
if the controller was in RAID mode. In that case, the foreign
module registers that it wants to be alerted if a certain
key sequence is pressed. (I don't have any details on how
that works. I do know that more than one RAID BIOS can be
present, each one using its own keyboard sequence to be triggered
during the BIOS POST.)

Now, what happens in the "Boot Menu" part of your BIOS ?
I haven't a clue, how any 8212F connected devices, or RAID
arrays, would appear in that menu. Obviously, "PM-xxxx" or
"PS-xxxx" talks of primary master or primary slave devices
(i.e. Southbridge ports, tightly integrated with main BIOS
etc). How do INT 0x13 registered devices appear ? I haven't
a clue.

Anyway, check your "Interrupt 19 capture" setting. A
real mystery, would be why the default is [Disabled].

What I did, the last time I had trouble installing Linux, is
booted a LiveCD, and ran "dd", and used /dev/zero to overwrite
the first 50MB or so of the physical drive. With absolutely
no partition information available on the disk anymore,
install went smoothly. The same technique also pays off, when
you want to put Windows on the Linux drive later (i.e. start
fresh). Just use "dd" as a disk eraser :-) You only need to
wipe out the first part of the disk, to keep those installers
happy.

Paul