[syslinux] VirtualBox 4.1.x can reproduce bug 45

[Ady]

Short summary:
I think bug #45
 http://bugzilla.syslinux.org/show_bug.cgi?id=45 
"Regression in Syslinux 6.xx. Doesn't 'hand over' to linux kernel"
can be reproduced using VirtualBox 4.1.x while trying to boot a 
relatively-newish Linux kernel.

Now, for more details...

Under VBox 4.1.x and using ISOLINUX 4.xx, a newish Linux kernel boots 
correctly.

Under VBox 4.1.x and using ISOLINUX 6.xx, the same newish Linux 
kernel fails to boot. This is the same exact system, except for the 
version of Syslinux (ISOLINUX) used in the ISO image that is booting 
the VM.

As mentioned in bug #45, the VM initially boots to Syslinux 6.xx, but 
when trying to boot the Linux kernel, it fails to complete the boot 
process.

Depending on the specific boot command (specific kernel, initrd...), 
the screen might show some initial row(s), similar to:
Loading kernel... OK
Loading initrd... OK

and then it just hangs there. Or, it might clear the screen and a 
cursor might show up at the upper-left area of the screen, and then 
just hangs.

Just to be sure, I have waited several minutes before closing the VM. 
The same kernels are able to complete the boot process using Syslinux 
4.xx without problems.

Although the exact behavior seen on screen might vary, the main 
behavior is the same: Syslinux 4.xx works, 6.xx fails.

Now, updating VBox to version 4.2.x, the same VM can successfully 
boot, whether with Syslinux 4.xx or with 6.xx. This seems to suggest 
that there is some bug in VBox 4.1.x. But, whichever the bug in VBox 
4.1.x, the behavior reflects real systems, as exposed by reports such 
as those in bug #45.

For testing this behavior under VBox 4.1.x, I have tried recent 
releases of Gparted Live, Clonezilla Live, ArchLinux... I used the 
original ISO images (which are already using ISOLINUX 6.xx), and I 
also re-built the images with Syslinux (ISOLINUX) 4.xx.

Perhaps testing Syslinux 6.xx under VBox 4.1.x might help solve bug 
#45?

TIA,
Ady.