Re: C/H/S from user space

[Nick Warne <nick@linicks.net>]

 > So, since Linux doesn't destroy that information remaining in
> the BIOS tables, I show how to make it available to a 'root' user.
> Observation over several machines will show that the BIOS always
> uses the same stuff for large media and, in fact, it has no choice.
> Basically, this means that the first part of the boot-code, the
> stuff that needs to be translated to fit into the int 0x13 registers,
> needs to be below 1024 cylinders, 63 sectors-track, and 256 heads.
> Trivial... even LILO was able to do that! Once the machine boots
> past the requirement to use the BIOS services, it's a CHS=NOP.


If I am off the mark here, forgive me.

Since I moved exclusively to GNU/Linux 2 years ago, I notice when I
update kernel I get this:

nick@linuxamd:nick$ sudo /sbin/lilo -v
LILO version 22.5.9, Copyright (C) 1992-1998 Werner Almesberger
Development beyond version 21 Copyright (C) 1999-2004 John Coffman
Released 08-Apr-2004 and compiled at 00:18:50 on May 21 2004.

Warning: LBA32 addressing assumed
Reading boot sector from /dev/hda2
Warning: Kernel & BIOS return differing head/sector geometries for device 0x80
    Kernel: 65535 cylinders, 16 heads, 63 sectors
      BIOS: 1024 cylinders, 255 heads, 63 sectors
Warning: Kernel & BIOS return differing head/sector geometries for device 0x81
    Kernel: 29777 cylinders, 16 heads, 63 sectors
      BIOS: 1024 cylinders, 255 heads, 63 sectors

Now, from day one I never used the -v option with lilo, but as I get
more experienced (!) I do now and see the above... I have never
investigated due to worrying if I start messing with it I will trash
my disks - as I see all anyway on this disks (and no errors), all
works great/fast etc.

Is this what is going on here (re this thread?).

Nick
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