A Remap Address Space Controller controls access to an address space by selectively remapping a physical address of a transaction received from a controller to form a remapped physical address according to a current execution context of the controller. The selective remapping is based on a determination of whether the current execution context of the controller allows the transaction to access the address space. Remap Address Space Controller selectively provides the transaction with the remapped physical address to a memory bus based on the determination of whether the current execution context of the controller allows the transaction to access the address space.