Embedded systems are applications used for specific tasks or as partof a general purpose, having constraints and design metrics. Thesesystems are implemented using microprocessors, with a favorableoption being the RISC (Reduced Instruction Set Computer), whichhas a reduced number of instructions and shorter execution time. Ahighlight within the RISC architecture is the RISC-V, an open andstable instruction set. Since the increase in reliability is essentialfor embedded systems operating in critical environments, thereis a need for fault tolerance provision in hardware and software.Thus, considering design options for operating systems aimed atembedded systems, the Rust programming language is a safe alternativedue to its efficient memory management. Therefore, thiswork proposes implementing a fault tolerance technique in a preexistingoperating system for the RISC-V architecture, aiming toincrease reliability in critical environments. The technique chosenfor implementation was the triple modular redundancy appliedto the operating system’s processes. After the implementation, anerror injection was performed through an emulator to validate theprovision of reliability. Finally, we evaluated the cost and performancemetrics, consolidating the implementation and the reliabilityimprovement with a justifiable increase in costs and performance.