Syslinux - Dec 2010 - Report: Acer Travelmat stupid MBR check

Just in case we get a report like this when the Syslinux MBR is used
together with an Acer Travelmate:

===========================================================================I
have an Acer Travelmate and had the known ?Unregistered Exception
Handler? error at boot time.

Short Explanation:
The laptop starts up bios and when the bios wants to boot from any media
(not even your harddisk) the exception is thrown.

Reason:
The Diskcryptor MBR starts with 0xeb(jmp). The original M$ mbr starts with
0x33(xor ax,ax).
Some bioses(like mine) try to detect if a drive has a MBR or if it is a
removable drive without MBR.
Very simple here:
Sector0,Position0==0x33 => MBR => normal partitioned harddisk.
Sector0,Position0==0xeb => Boot Sector assumed => emulate a hard disk(this
is what makes usb-sticks without mbr bootable as harddisks, and makes my
acer crash)
============================================================================http://reboot.pro/10503/page__pid__92239#entry92239

- Gert Hulselmans

Gert Hulselmans wrote:
> Just in case we get a report like this when the Syslinux MBR is used
> together with an Acer Travelmate:
>
>
===========================================================================>
I have an Acer Travelmate and had the known ?Unregistered Exception
> Handler? error at boot time.
>
> Short Explanation:
> The laptop starts up bios and when the bios wants to boot from any media
> (not even your harddisk) the exception is thrown.
>
> Reason:
> The Diskcryptor MBR starts with 0xeb(jmp). The original M$ mbr starts with
> 0x33(xor ax,ax).
> Some bioses(like mine) try to detect if a drive has a MBR or if it is a
> removable drive without MBR.
> Very simple here:
> Sector0,Position0==0x33 => MBR => normal partitioned harddisk.
> Sector0,Position0==0xeb => Boot Sector assumed => emulate a hard
disk(this
> is what makes usb-sticks without mbr bootable as harddisks, and makes my
> acer crash)
>
============================================================================http://reboot.pro/10503/page__pid__92239#entry92239
>
> - Gert Hulselmans
>
"Fixed" in
http://git.zytor.com/?p=syslinux/syslinux.git;a=commit;h=d0f275981c9289dc4b8df64e72cd9902bf85aebe

- Gert Hulselmans