The Linux Foundation Embedded Linux Conference 2013 An Insight into the Advanced XIP Filesystem By Aaditya Kumar San Francisco, California AXFS is a read only file system which supports both compressed and execute-in-place features. The main advantage of AXFS is that it allows individual pages in an executable image to be XIP or not (as opposed to other XIP systems which require the entire image to be XIP). This results is smaller memory sizes and faster program launches, in some scenarios. However, to achieve this, a profiling pass is required to determine the pages to map directly from the filesystem. Details of the design of AXFS and how to use it will be presented. A performance comparison of AXFS in different usage scenarios will also be shown, including use of AXFS in combination with other optimization techniques. AXFS was recently submitted for inclusion in the LTSI 3.4 kernel release.