The ever-growing complexity of today's embedded system, and the extra functional requirements like temporal or energy consumption constraints are one of the more exciting challenges for today's embedded system designers. Keeping the design space as open as possible, especially with regards to the hardware (HW) or software (SW) assignments of the system functions, are key points to minimize the project risk. In this paper, we propose a HW/SW Component-Based System Engineering framework for Real-Time Operating Systems (RTOS) services. The proposed approach combines the flexibility and power of software component based approach with the adaptability and performance of reconfigurable hardware architectures. This study focuses on the RTOS timing services case study. We show in this paper the value of such an approach especially in a context of precise time-driven requirements.