[syslinux] Multiboot pendrive with GPT - a tricky solution which could improve syslinux behavior

[H. Peter Anvin]

On 06/17/2010 10:52 PM, Emilio Lazo Zaia wrote:
> Hello!
> 
> I'm posting some experiences with GRUB0/1 + sys/extlinux + MBR/GPT in a
> pendrive with 15 partitions. This could be helpful improving
> sys/extlinux.
> 
> I did make a bootable pendrive with 14 distros using a GPT partition
> table and a tricky solution to let sys/extlinux boot from every
> partition chainloaded from GRUB (GRUB0 or GRUB1).
> 
> Having a MBR schema, sys/extlinux can't be chainloaded from GRUB in a
> partition >4, right? in my case, with a GPT schema, sys/extlinux never
> can't be chainloaded from GRUB0/1.
> 

This is in fact doubly wrong.  Syslinux proper is in fact
partition-format-agnostic (with the sole exception of chain.c32)... it
doesn't care about the partition table format *at all*.  Even when using
an MBR partition table, it can support logical partitions (> 4).

The only thing needed to boot Syslinux with GPT is to have a GPT MBR.

chain.c32 *does* need to be updated to support GPT; this is in fact my
next Syslinux task before 4.00 release.

	-hpa

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