From: Mark Lundeberg <[EMAIL PROTECTED]>
Subject: Re: stage1_lba trouble
Date: Mon, 9 Aug 1999 14:51:04 -0700 (PDT)
> from shell:
> drive 0x81: C/H/S = 621/128/63, The number of sectors = 5007744, LBA
This is not the correct information. The grub shell cannot detect if
LBA is supported anyway, because the shell cannot call BIOS in
UNIX. I'll suppress the CHS/LBA output in the shell.
> from native:
> drive 0x81: C/H/S = 620/128/63, The number of sectors = 4999680, CHS
>
> Ugh. CHS access, and 1 less cyl.
It is no problem that the number of the cylinders reported is 1 less
than the actual one. The reason can be found in some hardware manuals.
The real problem is not to detect LBA. Have you turned on LBA mode
for your drive really?
> But, AFAIK, CHS only allows heads to get up to 16.
That is not correct. Modern BIOSes allow heads up to 255. This
method is called "logical geometry" and "Large mode". The name
"logical geometry" is incorrect, because C/H/S is "logical" anyway,
though. So recent BIOSes should be able to access <8GB regions,
perhaps your BIOS can do.
> of whether to use LBA or not. Maybe we should check the Linux source to
> see how they detect LBA.
Linux does not use BIOS to access hard disks.
----------------------------------------------------------------------
OKUJI Yoshinori <[EMAIL PROTECTED]> ^o-o^
http://duff.kuicr.kyoto-u.ac.jp/~okuji (in English) m /
