Memory access protection apparatus and methods
AssigneeApple Inc.
InventorsSaurabh Garg, Karan Sanghi, Vladislav Petkov, Haining Zhang
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Abstract
Methods and apparatus for registering and handling access violations of host memory. In one embodiment, a peripheral processor receives one or more window registers defining an extent of address space accessible from a host processor; responsive to an attempt to access an extent of address space outside of the extent of accessible address space, generates an error message; stores the error message within a violation register; and resumes operation of the peripheral processor upon clearance of the stored error message.
Claims20
A method for registering access violations of host memory, comprising:
- receiving one or more window registers defining an extent of address space within the host memory that is accessible by a peripheral processor from a host processor;
- responsive to an attempt to access an extent of address space outside of the extent of accessible address space, generating an error message by the peripheral processor;
- storing the error message within a violation register;
- and
- preventing access of the host memory by the peripheral processor until the host processor has cleared the error message.
A computing device comprising a memory mapped system, the computing device comprising:
- a host processing device comprising a host CPU and a host memory management unit (MMU);
- a peripheral processing device comprising a peripheral CPU, a peripheral MMU, peripheral memory and a peripheral direct memory access (DMA) unit;
- and
- a host memory accessible by both the host processing device and the peripheral processing device;
- wherein the peripheral processing device further comprises logic configured to:
- receive one or more window registers defining an extent of address space within the host memory that is accessible by the peripheral processing device from the host processing device;
- generate an error message responsive to an attempt to access an extent of address space outside of the extent of accessible address space;
- store the error message within a violation register located within the peripheral memory;
- and
- prevent access of the host memory by the peripheral processing device until the host processing device has cleared the error message.
A peripheral processing device configured to register access violations of host memory within a memory mapped system, the peripheral processing device comprising:
- a peripheral CPU, a peripheral MMU, peripheral memory and a peripheral direct memory access (DMA) unit and further comprising logic configured to:
- receive one or more window registers defining an extent of address space within the host memory that is accessible by the peripheral processing device from a host processor;
- generate an error message responsive to an attempt to access an extent of address space outside of the extent of accessible address space;
- store the error message within a violation register;
- and
- prevent access of the host memory by the peripheral processing device until the host processor has cleared the error message.
Dependencies are inferred from the claim text.