A method and apparatus configure a trusted domain and a plurality of isolated domains in a processor core. Each isolated domain is assigned a unique domain identifier. One or more resources are associated with each isolated domain. The associations are stored as permissions to access physical addresses of resources. Code to be executed by a hardware device is assigned to one of the isolated domains. The domain identifier for the assigned isolated domain is written to the hardware device. When the hardware device executes the code, each instruction is logically tagged with the domain identifier written to the hardware device. An instruction includes request to access a physical address. The hardware device compares the domain identifier of the instruction with the permissions. If the permissions allow the domain identifier to access the physical address, then access to the resource at the physical address is allowed. Access is otherwise blocked.