Disable the floppy devices (fdc0, fd0) and parallel port device (ppc0) on Amazon EC2 instances. They are not present on these machines and output an error on boot (see below);
# dmesg | grep fdc
fdc0: <floppy drive controller> port 0x3f0-0x3f5,0x3f7 irq 6 drq 2 on acpi0
fdc0: does not respond
device_attach: fdc0 attach returned 6
fdc0: No FDOUT register!
# dmesg | grep ppc
ppc0: cannot reserve I/O port range