Re: Linux not adhering to BIOS Drive boot order?

David Balazic (david.balazic@uni-mb.si)
Wed, 17 Jan 2001 11:56:53 +0100


Matthew D. Pitts (mpitts@suite224.net) wrote :

> Guys,
>
> > And this is a problem that has plagues all PC operating systems, but has never
> > been a problem on the Macintosh. Why? Because the Mac was designed to handle
> > this problem, but the PC never was.
>
> Quite true on this point.

Amiga handles it too.

> > The Mac never enumerates its devices like the PC does (no C: D: etc, no
> > /dev/sda, /dev/sdb, or anything like that). It also remembers the boot device
> > in its EEPROM (the Startup Disk Control Panel handles this).
>
> For ATA drives the bios handles this.

No it doesn't. Put your root-fs on hda6 ( not unusual in dual boot
setups ),
delete hda5, watch your linux fail to boot.
( the kernel will be loaded , but it won't find the root-fs , because it
looks
in hda6 , but the partition has "migrated" to hda5 )

>
> > The only way to solve this problem is the DESIGN IT INTO THE OS! Someone needs
> > to stand up and say, "This is a problem, and I'm going to fix it." There needs
-------------------------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Amen to that !

> > to be a "device mount order database" or some kind, and all the disk drivers
> > need to access that database to determine where to put the devices it finds.
>
> NO! What needs to happen is:
> 1) the person who installs a second scsi card should read the manual BEFORE
> installing it so they know how to disable the boot features if they aren't
> needed,

This won't fix the "kernel doesn't find root-fs" problem.

>
> or
>
> 2) install only one bootable scsi card, period.

Same ( or similar ) problem as before ...

> Anything else is a useless kludge that will come back and bite us in the
> ass.

Kludges are bad, unfortunately that is all we have currently :-(

>
> > The only problem is BIOS boot. That information is, I believe, stored in the
> > ESCD, but I don't know if it's reliable enough and complete enough to be usable
> > by Linux.
>
> It seems to work well enough.

For the "load the kernel" part.
Most of the times.

>
> Matthew D. Pitts
> mpitts@suite224.net
>

-- 
David Balazic
--------------
"Be excellent to each other." - Bill & Ted
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