The syntax for expressions in the linker script language is identical to that of C expressions, except that whitespace is required in some places to resolve syntactic ambiguities. All expressions are evaluated as integers. All expressions are evaluated in the same size, which is 32 bits if both the host and target are 32 bits, and is otherwise 64 bits.
You can use and set symbol values in expressions.
The linker defines several special purpose builtin functions for use in expressions.