Re: How to debug 'out of disk' error.

[Vladimir 'φ-coder/phcoder' Serbinenko]

On 16.03.2011 18:32, Lennart Sorensen wrote:
> On Wed, Mar 16, 2011 at 04:29:32PM +0100, Vladimir 'φ-coder/phcoder' 
> Serbinenko wrote:
>   
>> On 16.03.2011 16:13, Lennart Sorensen wrote:
>>     
>>> I am trying to figure out why grub2 (from Debian Squeeze) gives an 'out
>>> of disk' error when trying to boot from the HD after doing an install.
>>> It ends up at a grub rescue prompt, given it can't even read the disk
>>> well enough to load the full grub.  Doing ls shows the disks, and I can
>>> show the root directory of a partition, but anything further seems to
>>> hit the same 'out of disk' error.
>>>
>>>   
>>>       
>> ls -l should show how big it thinks the disk is. Compare it with its
>> real size
>>     
>>> The system is a Compulab CM-iTC which uses an intel tunnelcreek atom
>>> (the new one) with a phoenix bios.  So far Compulab's response when told
>>> it won't boot grub2 was "We know, but syslinux works fine.", which to
>>> me is not a solution at all.  The same system also hangs the Linux 2.6.32
>>> kernel unless 'edd=off' is added to the kernel command line.
>>>
>>>   
>>>       
>> Looks like int13 is borked. Perhaps it's borked in a way which prevents
>> GRUB from detecting 13/42 function. You can try to force int13/42 by:
>> === modified file 'grub-core/disk/i386/pc/biosdisk.c'
>> --- grub-core/disk/i386/pc/biosdisk.c    2011-01-04 14:42:47 +0000
>> +++ grub-core/disk/i386/pc/biosdisk.c    2011-03-16 15:28:26 +0000
>> @@ -145,6 +145,8 @@
>>  {
>>    struct grub_bios_int_registers regs;
>>  
>> +  return 1;
>> +
>>    regs.edx = drive & 0xff;
>>    regs.eax = 0x4100;
>>    regs.ebx = 0x55aa;
>>     
> So I now have some debug info:
>
> version=48
> total_sectors=156312576 C=16383 H=16 S=63
> error: hd0,msdos1 out of disk.
> Entering rescue mode...
> grub rescue>
>
>   
These are correct values. However it may be that the correct value is
returned only on the first call. Could you try forcing

version=48
total_sectors=156312576


> So version is returning something, and it is actually getting the disk
> size properly.  I wonder what else could cause the out of disk message
> then.
>
>   


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko