Pre-Silicon Host-based Unit Testing of Driver Software using SystemC Models

Transcription

1 Pre-Silicon Host-based Unit Testing of Driver Software using SystemC Models Aravinda Thimmapuram Somarka Chakravarti Tamal Saha Rathina Thalaiappan Accellera Systems Initiative 1

2 Agenda Introduction Problem Statement Proposed Solution Benefits Differences between traditional host based testing Test Setup Challenges Results Accellera Systems Initiative 2

3 Introduction SystemC models are used to create Virtual Prototypes(VP) for improving Time-to-Market (TtM) HW Design System Integration and test System Design SW Design Specification complete HW Prototype HW/SW design complete Product complete Shift Left HW Design System Integration and test TtM Gain System Design SW Design Specification complete HW/SW design complete Product complete VP is used for System Software bring up. Pre-requisites to enable this : Well verified low level Driver Software which are used by System Software Accellera Systems Initiative 3

4 Problem Statement In the absence of complete feature testing of the driver software, considerable amount of time and effort is spent in bringing-up the application software on VP Is it possible to enable the complete feature testing of the low level driver software before the availability of VP? Accellera Systems Initiative 4

5 Proposed Solution The core idea is to integrate the SystemC model in the driver SW development/unit testing framework. The integration does not need any changes to either SystemC model or the driver SW Creation of a glue layer based on client-server approach which enables communication between driver SW and SystemC model. Using client server approach allows the SystemC simulation and the driver regression to run as separate processes, possibly on different machines. Accellera Systems Initiative 5

6 Benefits Provides a reliable verification environment for SW before the VP is available as this approach needs only the SystemC model which are pre-verified. Provides a powerful unit level HW-SW debug environment while the driver SW is being developed Easy to plug-in as a gating item for SW release. Re-usable glue layer logic which can be re-used across IPs Driver team is relieved of the effort to develop test/reference model Results in saving effort Gets an independent view of the reference implementation Faster simulation Accellera Systems Initiative 6

7 Differences between traditional host based testing Traditional Host-Based testing is looked at as : SW code runs on the Host Machine and register/memory accesses are trapped and directed to the C/C++/SystemC model. Typically SW and model are executed together as single process. How this is different Enables running of SW and SystemC simulation as separate processes Scalable approach - Multiple clients can talk to one server; hence multiple SW instances/regressions can be tested simultaneously Accellera Systems Initiative 7

8 Test Setup TLM2.0 Blocking Interface Read/write Commands Common layer Re-use across IPS SystemC IP SystemC Unit TB Push Transaction Interrupts Interrupts Glue Logic Core Server Layer Delivered by modelling team Interrupt Messages Register Access Messages TCP/IP Bridge Driver Test Suite Driver SW Layers HAL Emul Glue Delivered by Driver Team Accellera Systems Initiative 8

9 Challenges Synchronization between SW and simulation which run as separate processes Blocking register access messages from client side Queueing transactions in SystemC test bench Read value is updated in one thread and updated in another thread. Acquiring mutex before sending messages from client side Client code should be updated to handle multiple messages sent from server to client in a single packet. E.g.: Message: write 0x88 0x3f irq 0 (Write message and interrupt raised in same packet) In receive path, implemented a while loop to process receive buffer Scaling to multiple SW instances Accellera Systems Initiative 9

10 Results Complete re-use of both SystemC model and driver SW as delivered by the respective teams This is important when we consider the re-use of the model across different use-cases All applicable tests in the SW regression were executed Accellera Systems Initiative 10

11 Questions?? Accellera Systems Initiative 11