[syslinux] [PATCH] isohybrid: user options

[H. Peter Anvin]

Thomas Schmitt wrote:
>> I don't know if it would accept a negative
>> sbsector offset
> 
> That would still not help with the LBA pointers
> of the directory tree.
> Example:
>   On /dev/sda the content of File /x starts at
>   LBA 10000. That would be the number written
>   in the ISO directory record for /x.
>   If you now mount /dev/sda1 -o sbsector=-64
>   then the content of /x begins at sda1 block
>   address 9936.
>   The directory record (which is displaced itself,
>   and will not be found) still bears the address
>   10000.

Ah, yes, you're right.  Which means mounting /dev/sda is the only option
(or we'd have to add a new option to Linux, but it would still be
Linux-specific.)

The one reason for this, by the way, is that some unidentified BIOS
apparently tries to read the MBR (presumably to figure out what geometry
to fake) and decided it was invalid.

Since I don't know which BIOS and under what circumstances, I can't
experiment with it, either.

	-hpa