If I change the BIOS Memory config so that everything above 640k is Extended instead of some being Expanded then my custom kernel doesn't immediately reboot. Instead it just hangs with a cursor on the screen and doesn't print anything. Getting annoyed with the lack of a reset button on the T5200 too.
Would be nice if there was a way I could get qemu to act exactly like the T5200 so I don't have to keep testing on the real hardware.