Re: Understanding GRUB details

[Robert Millan]

On Mon, Dec 14, 2009 at 05:28:32PM -0600, Bruce Dubbs wrote:
> into memory.  The memory location is an absolute physical address of  
> 0x07C000, which is one 512-byte sector below the 1st 32K memory  
> boundary.  I think, but cannot confirm, that this memory location is for  
> historical reasons only.

Yes.

>   The BIOS passes the disk drive being booted via the DL register. This 
> value would normally be 0x80 for the first hard drive and is equivalent 
> to GRUB's (hd0), but grub-setup may over-ride it and set it to 0x80.

This sounds wrong.  I think it could be doing this, but only in desperate
situations (e.g. %dl was obviously wrong).

The basic problem is that we can't predict BIOS disk order reliably.  This
is a recurrent issue throurough different parts of GRUB.

-- 
Robert Millan

  "Be the change you want to see in the world" -- Gandhi