interface

Virtual Interfaces

Virtual Interfaces enable the firmware application that runs on the FVP simulation model to interact with external resources on the host computer.

The FVP simulation models support the following Virtual Interface types:

• VIO interface controls simple binary state I/O, such as LEDs and switches (maps to CMSIS-Driver VIO).
• VSocket interface for IP socket connectivity (maps to IOT-Socket).
• VSI interface for 8 independent data streaming channels (maps to CMSIS-Driver vStream).

The folder interface contains:

interface/
├── include/          # C header files for firmware (arm_vio.h, arm_vsi.h, arm_vsocket.h)
├── python/           # VSI Python template scripts to implement host-side peripheral behavior for VSI
├── audio/            # VSI Audio interface implementation (legacy, use vstream_audio instead)
├── video/            # VSI Video interface implementation (legacy, use vstream_video instead)
├── sensor/           # VSI Sensor interface templates and examples
├── vio/              # VIO implementation for FVPs
├── vsocket/          # VSocket implementation
└── vstream/          # VSI VStream interface for data streaming

VSI Channel Mapping

The VSI channels (VSI0 .. VSI7) for data streaming use Python scripts to interact with external resources.

The folder python contains vanilla VSI Python template scripts that provide the basic framework for implementing peripheral behavior. These templates serve as starting points for creating custom VSI peripheral implementations.

• arm_vsi0.py - arm_vsi7.py: Template implementations for all 8 VSI channels
• arm_vio.py: Template for Virtual I/O interface

The following table shows how VSI channels are assigned in the provided implementations:

VSI	Folder	Purpose	Description	Port
0	vstream	Audio Input	vStream Audio In - streams audio data into FVP	6000
1	vstream	Audio Output	vStream Audio Out - streams audio data from FVP	6001
2	sensor	Sensor Interface	Generic sensor data streaming (accelerometer, etc.)	-
3	-	Available	Used in SDS Framework for data streaming	-
4	vstream	Video Input	vStream Video In - streams video frames into FVP	6004
5	vstream	Video Output	vStream Video Out - streams video frames from FVP	6005
6	vstream	Video (Additional)	Additional video channel for multi-stream scenarios	6006
7	vstream	Video (Additional)	Additional video channel for multi-stream scenarios	6007

Implementation Details

vStream Implementations (vstream/ folder):

• Audio Channels (VSI 0-1): Implement CMSIS-Driver vStream_AudioIn and vStream_AudioOut interfaces

  • Support various audio formats (8/16/24/32-bit samples, mono/stereo, multiple sample rates)
  • Connect to system audio devices or audio files (WAV format)
  • Use audio servers for inter-process communication with the FVP

• Video Channels (VSI 4-7): Implement CMSIS-Driver vStream_VideoIn and vStream_VideoOut interfaces

  • Support multiple color formats (Grayscale, RGB888, BGR565)
  • Configurable frame dimensions and frame rates
  • Connect to system cameras, video files, or display windows
  • Use video servers for efficient frame data transfer

Sensor Implementation (sensor/ folder):

• VSI 2: Generic sensor interface with templates for various sensor types
  • Supports accelerometer, gyroscope, temperature, and other sensor data
  • Flexible data injection from files or algorithmic generation
  • Configurable sampling rates and data formats

Legacy Implementations:

• audio/ folder contains legacy audio implementations (replaced by vstream)
• video/ folder contains legacy video implementations (replaced by vstream)

Usage Guidelines

When developing applications using VSI channels:

1. Choose the appropriate channel based on your peripheral type
2. Start from templates in the python/ folder for new custom peripherals
3. Multiple instances: Applications can use multiple VSI channels simultaneously for complex system simulations

Custom Implementations

For custom peripherals, you can reassign VSI channels as needed:

• Copy and modify template scripts from python/ folder.
• Configure the firmware to use the corresponding VSI base address.
• Implement custom peripheral behavior in the Python script.

This flexibility allows you to simulate virtually any memory-mapped peripheral with streaming data requirements.