Upon the boot of l4linux iso image using QEMU, I got the following:

vmlinuz | RAMDISK: ext2 filesystem found at block 0

vmlinuz | RAMDISK: Loading 3072KiB [1 disk] into ram disk... done.

vmlinuz | EXT4-fs (ram0): couldn't mount as ext3 due to feature incompatibilities

vmlinuz | EXT4-fs (ram0): mounting ext2 file system using the ext4 subsystem

vmlinuz | EXT4-fs (ram0): mounted filesystem without journal. Opts: (null)

vmlinuz | VFS: Mounted root (ext2 filesystem) on device 1:0.

vmlinuz | Freeing unused kernel memory: 144K (00709000 - 0072d000)

vmlinuz | Clocksource tsc unstable (delta = 3346692958 ns)

vmlinuz | /bin/sh: can't access tty; job control turned off

I even disabled power management and ACPI options in l4linux configuration, still the same fault.