Integrity (operating system)
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|Company / developer||Green Hills Software|
|OS family||Real-time operating systems|
|Source model||Closed Source (classified)|
|Marketing target||Embedded systems|
|Supported platforms||ARM, XScale, Blackfin, Freescale ColdFire, MIPS, PowerPC, x86|
INTEGRITY is a real-time operating system (RTOS) produced and marketed by Green Hills Software. It is royalty-free, POSIX-certified, and intended for use in embedded systems needing reliability, availability, and fault tolerance. It is built atop the velOSity microkernel and is intended mainly for modern 32- or 64-bit embedded system designs that support an MMU. INTEGRITY uses hardware memory protection to isolate and protect itself and user tasks from incorrect operation caused by accidental errors or malicious tampering. Supported platforms include variants of ARM and XScale, Blackfin, Freescale ColdFire, MIPS, PowerPC, and x86 computer architectures. Green Hills also provides INTEGRITY-178B, a DO-178B certified version for safety-critical applications.
Associated tools 
- MULTI IDE for building INTEGRITY projects (graphical configuration, version control, compiler/toolchain errors) and debugging the kernel and applications that run on the INTEGRITY operating system.
- EventAnalyzer for visual analysis of system level events associated with INTEGRITY tasks and address spaces.
- TimeMachine tool suite for INTEGRITY application execution path analysis, forward/backward execution and single stepping, and other debugging capabilities for INTEGRITY configurations that can acquire instruction and data trace information.
- Green Hills probe and SuperTrace probe for downloading INTEGRITY kernels to target hardware, and examining trace information.
- UML and modeling (Telelogic Rhapsody and IBM Rose RealTime UML).
- Flash memory programmer.
Associated middleware 
- Networking - wired/wireless TCP/IP IPv4/IPv6 protocols
- Graphics - 2D/3D/Video
- USB (includes 2.0)
- File systems
INTEGRITY-178B is the DO-178B–compliant and ARINC-653-1–compliant version of the INTEGRITY RTOS. It targets demanding, safety-critical applications containing multiple programs with different levels of safety criticality, all executing on a single processor.
The INTEGRITY-178B kernel's design guarantees bounded computation times by eliminating features such as dynamic memory allocation. An MMU is used to provide full-system memory protection for all components, including user applications, device drivers, and inter-partition communications. Clocks and timers are protected with access permissions and implemented entirely in software. INTEGRITY-178B uses memory protection and error-handling to provide a secure system with built-in fault isolation and tolerance. At the lowest level, the kernel is protected from malicious access through its object-oriented design and access verification. The auditing and security engineering capabilities have allowed INTEGRITY-178B to obtain the EAL6 rating by the NSA. The TOE Architecture in the Security Target for the evaluation excludes components such as the file system and networking components from the definition of the TOE, focusing almost entirely on the core kernel itself.  Other operating systems, such as Windows or Linux, though evaluated at lower levels of assurance, generally include these capabilities within their TOE.
- "Board or bored? Lockheed Martin gets into the COTS hardware biz". VITA Technologies Magazine. December 10, 2010. Retrieved 9 March 2012.
- "Secure OS Gets Highest NSA Rating, Goes Commercial". Dark Reading. 2008-11-18. Retrieved 2009-05-09.
- "Integrity-178B Separation Kernel Security Target". SAIC. 2011-01-31. Retrieved 2011-03-22.