Abstract: An efficient PEIM-to-PEIM interface (“PPI”) database for storing data identifying one or more PPIs. The PPI database includes a linked list having one or more linked arrays of elements. The elements in each array store data identifying a PPI. Each array in the linked list of arrays may also include an element reserved for storing data identifying the last element in the array. Each array in the linked list of arrays may also include an element reserved for storing a pointer to a next array in the linked list of arrays. When the last array in the linked list of arrays becomes full, a new array is created, and a pointer to the new array is stored in the last array.