Apple Inc.
METHODS AND APPARATUS FOR CONTROL OF A JOINTLY SHARED MEMORY-MAPPED REGION

Abstract:

Methods and apparatus for using and controlling a jointly shared memory-mapped region between multiple processors in a pass-through manner. Existing data pipe input/output (I/O) techniques for mobile device operation enable high speed data transfers, decoupled independent operation of processors, reduced software complexity, reduced power consumption, etc. However, legacy functions and capabilities may only receive marginal benefits from data pipe I/O operation, and in some cases, may even suffer adverse effects from e.g., processing overhead and/or context switching. The present disclosure is directed to dynamically isolating and reaping back a jointly shared memory space for data transfer in a "pass through" manner which does not require kernel space intervention. More directly, a jointly shared region of host memory is accessible to both the peripheral client and the host client in user space.