| 摘要 |
A data processing apparatus has processing circuitry comprising a first secure area 501 and a second secure area 502 coupled by a monitor 520. A trusted storage device 522 stores at least one call gateway 524 comprising a transition instruction and access parameters. In response to a transition instruction, the monitor 520 is configured to determine when a call gateway 524 is stored in the trusted storage device 522. Following determination that the call gateway 524 is stored in the trusted storage device 522 the monitor 520 applies security credentials to the processing circuitry to enable the processing circuitry to perform functions in the second secure area 502. The access parameters may comprise a target function or a memory location. A security violation indication may be generated if the transition instruction and access parameter are not stored in the trusted storage 522. In another embodiment, a method of verifying call gateways provided in program instructions comprises detecting a defined number in the program instructions and detecting a call gateway comprising a transition instruction and access parameters at a predetermined position in relation to the defined number. |
