%0 Journal Article
%T A Fault Injection Analysis of Linux Operating on an FPGA-Embedded Platform
%A Joshua S. Monson
%A Mike Wirthlin
%A Brad Hutchings
%J International Journal of Reconfigurable Computing
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/850487
%X An FPGA-based Linux test-bed was constructed for the purpose of measuring its sensitivity to single-event upsets. The test-bed consists of two ML410 Xilinx development boards connected using a 124-pin custom connector board. The Design Under Test (DUT) consists of the ¡°hard core¡± PowerPC, running the Linux OS and several peripherals implemented in ¡°soft¡± (programmable) logic. Faults were injected via the Internal Configuration Access Port (ICAP). The experiments performed here demonstrate that the Linux-based system was sensitive to 199,584 or about 1.4 percent of all tested bits. Each sensitive bit in the bit-stream is mapped to the resource and user-module to which it configures. A density metric for comparing the reliability of modules within the system is presented. Using this density metric, we found that the most sensitive user module in the design was the PowerPC's direct connections to the DDR2 memory controller. 1. Introduction Over the last decade, Linux Operating Systems (OSs) have been used on several space-based computing platforms. NASA, for example, sponsored the FlightLinux project which culminated by demonstrating a reliable Linux OS on the UoSat12 satellite [1]. The use of Linux on the UoSat12 provided enough compatibility with ground systems to allow the satellite to be accessible over the Internet. Compatibility with ground systems is only one of the many reasons to use Linux on space-based computing platforms. Reliable hardware is essential for Linux to operate; however, integrated circuits (ICs) aboard space-based computing platforms are susceptible to failures known as Single-Event Upsets (SEUs). SEUs are random bit flips caused by high-energy particles that collide with the ICs. To ensure correct operation in the presence of radiation, ICs can be specially designed or ¡°hardened.¡¯¡¯ Unfortunately, radiation-hardened ICs are expensive and usually two or three silicon generations behind the state of the art [2]. These factors limit the use of radiation-hardened parts in space-based computing and leave engineers looking for alternatives. Field Programmable Gate Arrays (FPGAs) are among the state-of-the-art components that are of interest in space-based computing. FPGAs are microchips that contain an array of logic and interconnect that can be programmed and reprogrammed to perform almost any digital function. FPGAs often replace application-specific integrated circuits (ASICs) in space-based computing because designing for FPGAs is faster and less expensive than designing for ASICs. Additionally, reprogrammability allows designers to
%U http://www.hindawi.com/journals/ijrc/2012/850487/