[syslinux] Initial bootloader requirements of extlinux

[H. Peter Anvin]

On 11/06/2009 01:53 AM, Simon Rowe wrote:
> I'm trying to understand what the extlinux bootloader code written into a 
> partition needs to successfully start. I have a disk with four partitions, the 
> second is marked active and contains a kernel, initrd and root FS and extlinux 
> has been run on it. If I use mbr.bin as the initial bootloader the system 
> boots fine.
> 
> I need this to work within an environment supplied by a third party. They have 
> their own bootloader in the MBR and the above installation does not work. 
> After leaving their bootloader all I get is 'Boot error'.
> 
> Looking at extlinux.asm it appears that it expects ES:DI to point to the 
> partition entry and DL to contain the drive number. I've modified the MBR code 
> to do this but the system still doesn't boot. Is there anything else that 
> extlinux needs?
> 

DS:SI, not ES:DI.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.