PRODUCTS & TECHNOLOGY
Express Logic Introduces Memory-Protected Application Modules for ThreadX RTOS
Page 1 of 1
Express Logic has announced the introduction of ThreadX RTOS Memory Protection for downloadable application modules. Downloadable application modules, introduced earlier this year, enable ThreadX-based applications to execute functions dynamically loaded from local mass storage or a network. Memory protection for these modules adds a level of safety and security that enables developers to protect other modules and the ThreadX kernel itself against unintended damage from errant external access.
Memory protection is achieved with minimal software or hardware overhead by using the processor’s memory protection unit (MPU) or memory management unit (MMU) and no virtual address space. Any code within a particular module that attempts to access memory outside that module is prevented from making that access, and a system fault is generated. The RTOS then transfers control to an error handler that the application sets up to deal with the error. The module might then be disabled while allowing the rest of the system to continue operation, send an error message to an operator, or halt the system to prevent further damage.
As a result, applications gain increased reliability, security and functionality without the cost of increasing overhead or memory. ThreadX memory protection technology is suitable for situations where application code is developed by multiple team members, new application modules need to be added after the product is deployed, or partial firmware updates are required.
Virtual memory, memory protection and a kernel-module architecture are commonly found in desktop operating systems, such as Windows and Linux, and in larger RTOSs, such as VxWorks and QNX. Such architecture and functionality is not commonly found in small-footprint RTOSs like ThreadX, nor is the “big-system” method of implementation appropriate for such RTOSs, where even a small number of additional instructions can represent significant overhead. Such overhead can interfere with hard real-time response for which these systems are best suited. ThreadX is available in full source code form, royalty-free, with project license prices starting at $12,500.
Express Logic, San Diego, CA. (858) 613-6640. [www.expresslogic.com].