The ISP software stack operates across both the real-time processing unit (RPU) and application processing unit (APU) in a split architecture mode. A software driver within the APU extracts the ISP hardware configuration derived from the Device Tree Generator (DTG). These configurations then transmit to the RPU using the interprocess communication (IPC) to configure the ISP instance. The following diagram describes the structure of this split architecture.
Figure 1. Split Architecture
The APU software contains:
- Video for Linux2 (V4L2)/GStreamer/Bare-metal application
- ISP V4L2/Bare-metal driver
- IPC driver
The RPU firmware contains:
- ISP firmware stack including an 2A Algorithm
- Image Sensor driver