The Hexagon runtime is a part of the TVM runtime that facilitates communication between a host and a Hexagon device. There are two types of host/device arrangements that are supported:
The TVM runtime that contains Hexagon runtime is the one executing on host. In either case, there will need to be a separate TVM runtime (i.e. the libtvm_runtime.so
library) compiled for execution on Hexagon.
The prerequisite is to have Hexagon SDK installed, preferably version 3.5.0 or later. The Hexagon SDK can be downloaded from https://developer.qualcomm.com/software/hexagon-dsp-sdk.
It is also recommended to use as recent version of LLVM as possible, version 7.0.0 being the minimum (based on community feedback).
This will use Hexagon simulator, which is provided in the Hexagon SDK.
When configuring TVM (cmake), set the following variables:
USE_LLVM=llvm-config USE_HEXAGON_DEVICE=sim USE_HEXAGON_SDK=/path/to/sdk
You can then build the entire TVM with the usual command (e.g. make
).
This will use FastRPC mechanism to communicate between the AArch64 host and Hexagon.
When configuring TVM (cmake), set the following variables:
USE_LLVM=llvm-config USE_HEXAGON_DEVICE=device USE_HEXAGON_SDK=/path/to/sdk
You will need Android clang toolchain to compile the runtime. It is provided in Android NDK r19 or newer.
Set the C/C++ compiler to the Android clang for aarch64, and pass -DCMAKE_CXX_FLAGS='-stdlib=libc++'
to the cmake command.
Only build the runtime
component of TVM (e.g. make runtime
), building the entire TVM will not work.
The TVM runtime executing on Hexagon does not need to have support for Hexagon device in it (as it is only for communication between host and Hexagon device). In fact, it's only needed for basic services (like thread control), and so it should not contain support for any devices.
When configuring TVM (cmake), set the following variables:
USE_RPC=OFF USE_LLVM=OFF USE_HEXAGON_DEVICE=OFF USE_HEXAGON_SDK=/path/to/sdk
Please note that while suport for a Hexagon device is disabled, the Hexagon SDK is still needed and the path to it needs to be passed to cmake.
Set the C/C++ compiler to hexagon-clang
(included in the Hexagon SDK), and set CMAKE_CXX_FLAGS='-stdlib=libc++'
.
As in the case of Android, only build the runtime
component (e.g. make runtime
).