The document discusses embedded product line updates from AdaCore. It describes embedded development using bare boards or embedded OSes like VxWorks, PikeOS, and Linux. AdaCore's GNAT compiler and tools like CodePeer and SPARK Pro allow developing safety-critical and verified embedded applications in Ada for various targets like PowerPC, ARM, LEON and running on bare boards or operating systems. The document outlines new targets, multicore support, and certification efforts of AdaCore's runtimes. It also presents some example fun projects for embedded development.

2. Embedded Product Line
Update
José Ruiz
October 1st 2015

3. Outline
• What is embedded
• Overview of cross targets
– Embedded OSs / bare board
– What is new
• Fun projects

4. What is embedded?
• Executes on a platform different from the host used for building
• Characteristics
– Reduced memory and processing power
– Limited graphical interface
– Safety/mission-critical
– Real-time requirements
– …

5. Embedded is expressive!
• Profiles for safety/mission-critical
– Tasking
– Multiprocessor
– Object-Oriented Programming
– Exceptions
• Ada 2012 contracts
function Sqrt (X : Integer) return Integer with
Pre => X >= 0,
Post => ((Sqrt’Result ** 2 <= X) and then
((Sqrt’Result + 1) ** 2 > X));
task Cyclic
with Priority => 100,
CPU => 3;
end Cyclic;

6. Embedded is verifiable!
AdaCore tools
• Static Analysis Tools
– Coding standard (GNATcheck)
– Code metrics (GNATmetrics)
– Static stack analysis (GNATstack)
– Static analysis (CodePeer)
– Formal proofs (SPARK Pro)
• Dynamic Analysis Tools
– Unit testing (GNATtest / Aunit)
– Code coverage (GNATcoverage)
– Emulation (GNATemulator)
– Debugging (GDB)
Partners
• Static Analysis Tools
– Axivion
• Static Analysis
• Dynamic Analysis Tools
– VectorCAST
• Unit/Integration Testing
• Code Coverage
– Rapita
• Timing Analysis Tool
• Code Coverage
– LDRA
• Unit/Integration Testing
Qualified
Qualified
Qualified
Qualified
Qualified
Qualified
Qualified

7. How to do embedded development
On top of embedded OS
• OS responsible for
– BSP
– Tasking
– Multiprocessor
• OS supported
– VxWorks
– PikeOS
– LynxOS
– Embedded linux
– Android
Bare board
• Ada run time provides
– Start up code
– BSP
– Tasking
– Multiprocessor
• Targets supported
– PowerPC/e500v2
– ARM
– ERC32/LEON2/LEON3
– AVR

8. GNAT Pro on embedded OS
• Ada run time uses OS services
• User benefits from
– BSP provided by the OS
• File system, networking
– Portability provided by the
Ada run time
Ada Application
Ada Run Time
Operating System
Hardware

9. GNAT Pro for VxWorks
• VxWorks 6/7 & SMP
– PowerPC / e500v2
– x86 / x86-64
– ARM
– VxWorks Simulator
• VxWorks 5.5
– PowerPC
– x86 (baselined)
– 68K (baselined)
• VxWorks 653 (1.8-3.0 supported) & MC
– PowerPC / e500v2
– x86
• VxWorks MILS
– PowerPC
• VxWorks Cert 6
– PowerPC / x86
• VxWorks Cert 5
– PowerPC

10. Run Times for VxWorks
Cert
Zero Footprint
(SPARK
compliant)
Ravenscar Full Kernel Full RTP
VxWorks Cert 5 & 6
VxWorks 5
VxWorks 6/7
VxWorks 653
Certified

11. News for VxWorks
• New platforms
– VxWorks 653 3.0
– VxWorks 7
• New targets
– ARM and x86-64
• Multicore support
– VxWorks 6 & 7
– VxWorks 653 3.0
• Zero cost exception propagation (Ravenscar and Full run times)
• Debugging support
– Active collaboration between Wind River and AdaCore
– Enhanced compiler and Workbench debugger

12. GNAT Pro for PikeOS
• PikeOS 3.4 hypervisor
– Support for x86 and PowerPC
• Three run-time profiles
– ZFP, Ravenscar
– Minimal
• Zero cost exception propagation (Ravenscar run time)
Certified

13. GNAT Pro for LynxOS
• LynxOS-178 (2.2.2)
– PowerPC
• LynxOS 5
– PowerPC / x86
• Zero cost exception propagation (Ravenscar and Full run times)
Cert
Zero Footprint
(SPARK
compliant)
Ravenscar Full
LynxOS-178
LynxOS 5
Certified

14. GNAT Pro for embedded linux
• Generic port for embedded linux
– x86, ARM, PowerPC, e500v2
• Reference platforms
– Wind River embedded linux (PowerPC)
– ElinOS (PowerPC / x86)
• Full Ada run times
– Zero cost exception propagation
– Multiprocessor support

15. GNAT Pro for Android
• Jelly Bean 4.1
• Lollipop 5.1
• GDB support

16. GNAT Pro for bare boards
• Most of the run time is shared among targets
• Configurable run times
– Make it easy to adapt to new board
– Startup routine
– Memory map
– Floating point support
Ada Application
Ada Run Time
Multitasking core
Hardware
BSP

17. Bare board targets
• PowerPC / e500v2
• ARM
– ARM Cortex M3, ARM Cortex M4F, ARM Cortex R4F
• LEON
– LEON2, LEON3, ERC32
• Baselined ports
– AVR microcontrollers
– Lego Mindstorms NXT

18. News for bare boards
• Ravenscar
• Productizing support for multiprocessors
– PowerPC, working on LEON
– Fully partitioned model
• Math library in Ada
– Certifiable
• Extending Ravenscar
– Addressing restrictions limiting
expressive power
• Protected entry queuing
• Multiple entry queues per
protected object
0
3
1
2
Ravenscar system on monoprocessor
task Cyclic
with Priority => 100,
CPU => 3;
end Cyclic;
Certified

19. News for bare boards (II)
• Zero-cost exception propagation
– Ravenscar Full run times
• Setting up shared GitHub
– Collaborative environment for demos, BSPs, drivers,…
• Emulator/coverage for ARM

20. Certification of run times
Avionics DO-178B/C Certification
Bare board PowerPC Ravenscar run time SSIL
3/4
x86 PikeOS Minimal run time SSIL 3/4 (in
progress)
Railway CENELEC Certification
EN 50128:2011, 50126:1999, 50129:2003
Space
ECSS E-ST-40C Q-ST-80C
Cert run time PowerPC VxWorks 653 certified Level
A
Cert run time PowerPC VxWorks 6 Cert (Level A in
progress)
Cert run time PowerPC LynxOS 178 (Level A in
progress)
Bare board Ravenscar run time qualified
Level B and Level C (ERC32, LEON2, LEON3)

21. Bare board for fun
• Lego Mindstorms NXT
• ARM boards
– STM32F4-Discovery
– Atmel SAM4S (Cortex M4)
• Raspberry Pi 2
• Crazyflie
– SPARK for proving absence of run-time errors
– Ravenscar Ada tasking

22. Bare board for fun (II)
• Play with concurrent / parallel execution
• Develop embedded control systems
– Manually written code
– QGen to automatically generate Ada/C from Simulink/Stateflow
• Replace embedded OS by Ravenscar Ada run time
• Develop BSPs and drivers
• Use SPARK to prove
– Functional properties
– Absence of run-time errors

23. Summary
• Choice of OS / bare board
• Tasking available
– Multiprocessor getting there gradually
• We can make it work on small targets
– Small footprint, no dynamic memory, very low overhead
• You can trust the code embedded on your target
– You can use Ada 2012 and tools to help make your code reliable
• … and you can have fun with cross development!

24. Resources
• Tools
<www.adacore.com/gnatpro-safety-critical>
• Crazyflie
<blog.adacore.com/how-to-prevent-drone-crashes-using-spark>
• Solenoid engine on STM32F4
<blog.adacore.com/make-with-ada-all-that-is-useless-is-essential>
• Tetris in SPARK on ARM (SAM4S)
<blog.adacore.com/tetris-in-spark-on-arm-cortex-m4>