shim (jargon, memory management) A small piece of data inserted in order to achieve a desired memory alignment or other addressing property.
For example, the PDP-11 Unix linker, in split I&D (instructions and data) mode, inserts a two-byte shim at location 0 in data space so that no data object will have an address of 0 (and be confused with the C null pointer). See also loose bytes. [Jargon File] Last updated: 1994-12-21