meta-atp layer

The meta-atp layer supports building environments with traffic generation capabilities based on AMBA Adaptive Traffic Profiles (ATP).

Recipes

The meta-atp layer supports building the following software components:

• Arm's implementation of the AMBA ATP specification, namely the AMBA ATP Engine.
• Linux kernel modules and user API (UAPI) for programming ATP devices.
• Integration test suite for verification of kernel modules and UAPI.

It is also possible to build the AMBA ATP Engine as part of the final gem5 executable. For this, meta-atp extends the gem5-aarch64-native recipe to add the AMBA ATP engine code as extra sources.

Machines

The gem5-atp-arm64 machine extends the gem5-arm64 machine to instantiate a simulated platform with support for programmable AMBA ATP traffic generation. The platform includes the following models:

• ProfileGen model. This is the adapter layer between gem5 and the AMBA ATP Engine. It is the source of traffic into the gem5 host platform.
• ATPDevice model. Software can program it using the Linux kernel modules and UAPI to control traffic generation.

Usage

Users should add the meta-atp layer and layer dependencies to conf/bblayers.conf. See conf/layer.conf for dependencies.

Standalone Engine executable

Users can build the AMBA ATP Engine as a standalone native executable as follows:

bitbake atp-native

Users can run the executable through standard build scripts:

oe-run-native atp-native atpeng [--help | args...]

Integration of the Engine in gem5

Users should select the gem5-atp-arm64 platform in their conf/local.conf file.

Users can build the target image of preference, for example:

bitbake core-image-minimal

The resulting gem5 native executable contains the AMBA ATP Engine. The resulting target image contains the kernel modules, UAPI and test suite.

Users should run the environment as follows:

./tmp/deploy/tools/start-gem5-atp.sh

This script launches a fast simulation to fast-forward Linux boot. Once Linux boot is completed, the fast simulation switches into a detailed simulation for the final usable environment. Users can connect and interact with the environment as follows:

oe-run-native gem5-m5term-native m5term <PORT>

The connection PORT is announced by the deploy script as:

system.terminal: Listening for connections on port <PORT>

This is usually port 3456.

Users can verify access to the ATP device by running the integration test suite from within the simulated environment as follows:

test_atp.out