ThinkPad T42 and Slackware 14.0
 

Currently have Slackware 14.0 installed on a USB flash drive that works fine inside a VirtualBox, however when I try to boot it off an old IBM ThinkPad T42 I get the message that the system can't handle the kernel because of a lack of PAE. I have switched between the generic and huge kernels, but both give that message. According to the limit search results, the huge kernel is supposed to work on a system like this unless I'm missing something or reading things incorrectly. Anyone have any ideas?

Try booting with:

boot: huge.s

to use the kernel without SMP (and PAE) support. (At least, I think huge.s is still there...)

<EDIT>Either way, this should probably be on the installation board, rather than the general board.</EDIT>

that's just it... I am using the huge kernel off the USB flash, but I'm still getting this PAE message. Doing a 'grep HIGHMEM *' on the installation DVD for the config files for all the kernels reveal NONE of them have PAE turned off... a "bug"?

Huh... I was unaware that the huge.s kernel did that. It looks like even Debian is dropping non-PAE kernels in Wheezy. If CONFIG_HIGHMEM is the kernel option that enables PAE support, then it's been enabled in huge.s since at least 12.2.

Looking into the 14.0 kernel options, it appears that setting HIGHMEM4G on (allowing 4GB of memory rather than ~1GB) hides the PAE option, which makes me believe that it requires it to work, despite the kernel's own documentation saying that PAE is only explicitly enabled if HIGHMEM64G is on. Strange.

<EDIT>Debian is merely shuffling non-PAE kernels to i486, removing non-PAE i686 support.</EDIT>

Are you certain you are booting huge.s and not hugesmp.s?

The SMP kernel has PAE turned on:
The non-SMP kernel does not have PAE support turned on (not turned on is equal to having it off here):
Eric

Maybe your problem concerns VirtualBox. Try to mark the following option:

Settings | System | Processor | Enable PAE/NX