machine won't start

Tobias Weingartner weingart at tepid.org
Wed Jul 4 11:57:16 PDT 2012


Been down that path, and almost lost my sanity.  The code that probes
for disks via the BIOS (in openbsd's boot loader) is just as sensitive,
causing hangs, etc.  Writing that was... "interesting".  The partition table
entries are just about as sensitive (as you've found out), and the joy is
all the different ways that BIOS will interpret values (and hang on values).

Even better, I've seen BIOSen that would change the geometry information
returned on (a USB stick was common) based on the partition table information
that they may or may not have read from the first 512 bytes of a "disk".  Yuck.

-Toby.

On Wed, Jul 4, 2012 at 12:35 PM, Matthew Dillon
<dillon at apollo.backplane.com> wrote:
> :>     I consider it almost a lost cause.
> :
> :
> :Don't get it: trying to fix this is a lost cause?
>
>     Yah, because if we fix it for one BIOS we break it for another.
>     Hence, a lost cause.  There is no single fix which covers all BIOSs.
>
>                                                 -Matt





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