On Sat, Jan 07, 2012 at 02:30:52PM -0500, erik quanstrom wrote:
>
> the code assumes c/h/s. and if it (libdisk) can't find the geometry, it
> makes stuff
> up. that seems like a dubious assumption. not very clean at all.
>
> i was thinking that setting cyc2cyl=1 should cleanly remove this feature.
> it could then be reenabled with a command-line flag if necessary for
> some really ancient h/w.
We should be careful, because bootloaders whether take the c/h/s, or the
as is lba values (and the incorrect assumption is that c/h/s == lba
since this will defeat the purpose of lba).
But in the code, there are p->ctlstart and p->ctlend, that have the
correct values... and are not used. Perhaps simply using these values
when writing will suffice.
But whether I or another have/has to look carefully: doing blunders in
Plan9 zone is unfortunate but... Messing others' areas must be
forbidden. disk/fdisk(8) is the program that impacts others.
The MBR is the BIOS entry point so it shall not be botched. Furthermore,
with a booloader that has not the capability to select the primary to
boot, if the MBR is partially wrong, and the active partition not the
correct one, you have to have... a plan B (but perhaps not the well
known one ;).
--
Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
http://www.kergis.com/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C
