The PHDR_ADD_NULL directive causes the link-editor to add a specified number of additional program header entries of type PT_NULL at the end of the program header array. Extra PT_NULL entries can be used by post processing utilities.
PHDR_ADD_NULL = value;
value must be a positive integer value, and gives the number of extra PT_NULL entries to create. All fields of the resulting program header entries will be set to 0.