A mechanism is provided for non-disruptive replacing of a first software module with a second software module in an embedded system. The mechanism includes copying update control code from the first software module to memory space outside a memory location of the first software module, and then replacing the first software module with a second software module by storing the second software module in memory at a location which at least partially overlies the first software module. The replacing includes executing the update control code copied from the first software module during the replacing. Upon completing storing of the second software module, execution of the second software module is begun without resetting the system.