README

This directory contains a driver for the VCHIQ interface device, related header
files, a VCHIQ audio service driver and a sample program, which plays a sound
sample using this driver. VCHIQ is a message based interface between the VPU
(Video Processing Unit) of the Raspberry Pi and the ARM CPU. It is used to
transfer different kinds of media data.

Furthermore in the subdirectory addon/vc4/interface/ there is a partial port of
the accelerated graphics userland code, which implements the EGL, OpenGL ES,
OpenVG and Dispmanx APIs. Please have a look into the README file in this
subdirectory for more details.

To build the VCHIQ sound sample program, you have to build the Circle base
libraries and the Linux kernel driver emulation library in the directory
addon/linux/ first. Then enter these commands in the addon/vc4/ directory:

	./makeall clean
	./makeall

You will find the sample program in addon/vc4/sound/sample/.

The VCHIQ interface driver source code and portions of the VCHIQ audio service
driver source code are taken from Linux and are:

	Copyright (c) 2010-2014 Broadcom. All rights reserved.

Some portions are:

	Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.

This source code is licensed under GPLv2. Please refer to the header of these
source files for details.
