Linux Poison posted a guide about creating ISO-9660 CD-ROM filesystem images with genisoimage

genisoimage is a pre-mastering program to generate ISO9660/Joliet/HFS hybrid filesystems. genisoimage takes a snapshot of a given directory tree, and generates a binary image which will correspond to an ISO9660 and/or HFS filesystem when written to a block device.

  How to Create ISO-9660 CD-ROM filesystem images