Virtualization is a promising technology for running multiple operating systems (OS’s) on a single processor. Preparing an OS for use with virtualization, however, involves making some changes to the OS code, which must be repeated for each version, whether a new release or a client customization. Typically such changes are expressed as patches, but patches are often not portable from one version to another, and thus manual adjustments are needed as well. In this paper, we consider the use of the automated transformation system Coccinelle to perform the changes required to port several versions of Linux to the VLX hypervisor. Coccinelle provides a notion of semantic patches, which are more abstract than standard patches, and thus are potentially applicable to a wider range of OS versions. We have applied this approach in the context of Linux versions 2.6.13, 2.6.14, and 2.6.15, for the ARM architecture.