Abstract <p>The task of improving the reliability of critical real-time operating systems (RTOS) remains relevant. The use of detailed developer requirements provides new opportunities in this direction regarding memory management [9]. A new approach to static memory allocation in an RTOS with reliable memory isolation is presented. A method for constructing a static memory allocation tool (or memory layout designer) based on a formal description of the developer’s memory requirements is proposed. It is proposed to build a formal description without reference to the specific platform but on the basis of only the needs of the software being developed. General concepts are introduced that enable a universal approach to constructing a static memory allocation tool, a general scheme of the allocation algorithm is described, and requirements that must be taken into account when implementing each step of the algorithm are detailed. The described approach has been tested on real industrial projects and has shown its versatility, adaptability, and efficiency in designing static memory layout.</p>