Recently, the software of embedded systems grows increasingly complicated due to controversial needs of both rich functionalities and strict interrupt responsiveness. In order to deal with it, realtime virtualization technology for embedded systems is attracting interests. Virtualization allows multiple operating systems to run concurrently with minimal modifications, thus reduce the engineering cost. However, as the security of embedded systems getting more concerns in these days, current design of realtime hypervisor often makes it difficult to ensure the security without hardware virtualization support which is not widely available in the world of embedded systems. In this paper, we introduce Secure Pager which utilizes a common hardware design called core-local memory combined with check-sum based protections to enforce the spatial isolation without specific hardware virtualization support.