Customized 12.04.3 Ubuntu ISO fails to boot in Virtualbox -- getting stuck at the txt.cfg/Ubuntu boot screen

Question

I'm attempting to make a custom Ubuntu installer, but the ISOs that I'm generating fail to boot in VirtualBox 4.1.18.

The raw ISO (downloaded here: http://www.ubuntu.com/start-download?distro=server&bits=64&release=lts) will boot in virtualbox, but my custom ISO will not, getting stuck at the pre-boot screen that is generated by txt.cfg -- on which the contents of the txt.cfg are displayed.

This is a screenshot of what I'm seeing:

As a sanity test, I've tried to generate an ISO without a kickstart or preseed file to test if it's my changes that are causing it:

1. Mounted the iso as a loop device to /mnt/iso

2. mkdir -p /opt/serveriso/

3. cp -rT /mnt/iso/. /opt/serveriso/.

4. cd /opt/serveriso

5. mkisofs -D -r -V 'UBUNTU_HARDWARE' -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o /opt/ubuntu_hardware.iso /opt/serveriso

Can someone help me find out why Ubuntu is displaying the contents of my txt.cfg instead of running it?

edit: As I'm cp-ing from /mnt/iso, I assume that the issue lies in either VirtualBox or (more likely) my mkisofs line.

Answer 1

Added nosplash to the end of txt.cfg and it seemed to solve the issue.

edit: The lang file didn't have a newline. This was causing the installer to hang.