Hexagon apps are started from an app running on the apps processor of the SoC. A RPC mechanism (called FastRPC) is used to load a shared library on the DSP and the RPC stubs are generated from a IDL complier (qaic). The RTOS on the DSP is QuRT but is often abstraced by the DSPAL APIs.

Add cmake_hexagon as a submodule to your project.

In the CMakeLists.txt file for your project, add:

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake_hexagon")

Then add whichever modules you wish:

include(qurt_app)

or

include(linux_app)

or

include(bundle)

The QURT_BUNDLE function can be made to build DSP applications that have a simple apps proc side launcher app.

QURT_BUNDLE is used to specify the files and libraries to build into the DSP lib and into the apps application. The generated stubs are automatically build into the appropriate target.

The CMakeLists.txt file calls QURT_BUNDLE and requires that the file .idl exists for the IDL interface between the apps processor app and the DSP library.

QURT_BUNDLE(APP_NAME testapp DSP_SOURCES testapp_dsp.c APPS_SOURCES testapp.c APPS_INCS "-Iinclude" APPS_COMPILER arm-linux-gnueabihf-gcc )

For an app named testapp, the result will be:

• testapp_app - Run on apps processor
• libtestapp.so - copy to target at /usr/share/date/adsp/
• libtestapp_skel.so - copy to target at /usr/share/date/adsp/

The file testapp.idl is used in this example to create the stub functions that automatically get linked in to the app and DSP lib.

QURT_BUNDLE adds a rule to load the app onto the DSP (-load).

To load the testapp application to the target you can run the following command from inside the build tree:

cd build
make testapp-load

In the DSP lib CMakeLists.txt file:

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake_hexagon")
include(qurt_lib)

FASTRPC_STUB_GEN(hello.idl)

QURT_LIB(
	LIB_NAME helloworld
	IDL_NAME hello
	SOURCES helloworld_dsp.c
	)

An application that calls the IDL interface is required to load the library that runs on the DSP.

In the apps proc app CMakeLists.txt file:

set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake_hexagon")
include(linux_app)

FASTRPC_STUB_GEN(hello.idl)

LINUX_APP(
	APP_NAME helloworld
	IDL_NAME hello
	SOURCES helloworld.c
	)