Abstract

Commercial off-the-shelf (COTS) microcontrollers can be useful for non-critical processing on spaceborne platforms. Many of these microprocessors are inexpensive and consume little power. However, the software running on these processors is vulnerable to radiation upsets, which can cause unpredictable program execution or corrupt data. Space missions cannot allow these errors to interrupt functionality or destroy gathered data. As a result, several techniques have been developed to reduce the effect of these upsets. Some proposed techniques involve altering the processor hardware, which is impossible for a COTS device. Alternately, the software running on the microcontroller can be modified to detect or correct data corruption. There have been several proposed approaches for software mitigation. Some take advantage of advanced architectural features, others modify software by hand, and still others focus their techniques on specific microarchitectures. However, these approaches do not consider the limited resources of microcontrollers and are difficult to use across multiple platforms. This thesis explores fully automated software-based mitigation to improve the reliability of microcontrollers and microcontroller software in a high radiation environment. Several difficulties associated with automating software protection in the compilation step are also discussed. Previous mitigation techniques are examined, resulting in the creation of COAST (COmpiler-Assisted Software fault Tolerance), a tool that automatically applies software protection techniques to user code. Hardened code has been verified by a fault injection campaign; the mean work to failure increased, on average, by 21.6x. When tested in a neutron beam, the neutron cross sections of programs decreased by an average of 23x, and the average mean work to failure increased by 5.7x.

Degree

College and Department

Ira A. Fulton College of Engineering and Technology; Electrical and Computer Engineering

Rights

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