On Wed, 2006-03-29 at 05:14 -0500, Alan Cox wrote: > On Tue, Mar 28, 2006 at 05:20:40PM -0500, Peter Jones wrote: > > For all thinkpads that have this turned on it's for BIOS backup/restore > > features, a and other related features that the user (at least > > theoretically) paid for and may still want. Right now we're trashing > > them. > > > > I think ThinkPads make up more than 1% of cases, but I've got no real > > data to prove it with. > > This is one of the problems. On a thinkpad the HPA is used to hide stuff, > and on many boxes its used in a way we want to undo. In theory its just a case > of installers doing partitioning right and maybe snooping the DMI tables to > see if its a thinkpad... in theory 8) Yeah. But right now the installer doesn't have any data available about HPA at all, so it can't do the partitioning right if we're disabling HPA (which we are). Which means for FC6, we have to disable HPA by default, and conditionally re-enable it if there's no partition table entry that points above the top. Tangentally, I might add that if Fibre Channel, iSCSI, or similar ever invent a function like this, we better not screw it up as much as we have this time, because changing the geometry of another machine's disk is seriously not fun to recover from. Just my introspective thought for the day. > > > Looks basically sane. You have to run the ACPI taskfiles from the BIOS first > > > however or you are out of spec and anything can happen (although fortunately > > > it ususally doesnt) > > > > Ugh. Ok, I've got some reading to do before I get this in. Thanks for > > the info. > > The ACPI taskfile stuff is cooking already and should be mainstream soon. I > would suggest not worrying about it for the moment. You will need to sort the > HPA out after the ACPI stuff runs once it is in as on the thinkpad it also > edits the HPA settings when those run OK... is there a patch floating around for the _GTF stuff already? URL? Also, are (whoever's doing it) doing _GTM/_STM work as well? > > disable it entirely for IDE, which means if we ever want to do anything > > other than just disable it, we need control to be somewhere that can > > examine the system to see what we've done. Sadly, that probably means > > userland. > > I've not dug into the thinkpad far enough but I would guess that something > like > > read partition table > work out last sector used > if ( beyond hpa) > disable hpa > else > honour hpa > > will give the right answer for almost all cases, if not all. Yep, I already have this code. > Not sure what you > do if the drive has no partition table. Well, one thing to try would be to look at the first sector of the protected area and see what *it* has in it. On most thinkpads IIRC the first thing there is a bootable floppy image. And of course there's always the DMI option, but that's a bit of a blunt hammer -- especially since newer thinkpads have stopped using HPA. -- Peter -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
