[syslinux] isolinux: Generate GPT and Mac bootable images

[Matthew Garrett]

On Mon, Aug 08, 2011 at 12:52:43PM -0500, H. Peter Anvin wrote:
> On 08/05/2011 10:01 PM, Matthew Garrett wrote:
> > On Fri, Aug 05, 2011 at 02:48:00PM -0700, H. Peter Anvin wrote:
> > 
> >> Hmmm... as I recall, you can't put a bunch of padding before the xorw
> >> %bp, %bp... some broken BIOS requires that at offset 0... presumably
> >> some specific M$ MBR had that instruction first, and someone decided to
> >> use it as a magic signature.  Sigh.
> > 
> > Well that obviously makes things harder - we need to put ER at offset 0. 
> > Have you got an example of one of them? I'll try to chase it down and 
> > see if there's anything that can be done.
> > 
> 
> Also, remember that you end up having actual execution of code at offset 0!

Yeah. This disassembles to something harmless. Easiest approach would be 
to stick another xor at offset 0 - that should satisfy the Acers in the 
normal case, with it only being overwritten in the Mac case.

-- 
Matthew Garrett | mjg59 at srcf.ucam.org