Embedded Linux developer services provider Timesys is distributing a real-time Linux kernel for ARM9-based Atmel processors. The 2.6.24.4-rt4 kernel includes Ingo Molnar and Thomas Gleixner’s RT_PREEMPT patch, along with patches for high-resolution timers and other board-specific features for Atmel reference platforms.

The “RT Preempt” patch is the same used by Linux distributors Red Hat, Novell, and MontaVista, in the real-time versions of their commercial real-time Linux distributions. It is expected to reach the mainline kernel eventually, but has not been generally available pre-integrated into a full kernel offering. The patch provides guarantees for hard timing deadlines, required by many mission critical applications in industries like telecom, military, healthcare, or financial trading.

The new kernel and patches have been applied, configured, and tested to support real time features, says Timesys, although it did not say by whom. The kernel supports full kernel preemption, schedule-able interrupt handlers, high resolution timers, and mutexes with priority inheritance, says the company. The optimized kernel supports the Atmel ARM9-based reference platforms, including the AT91SAM9260, AT91SAM9261, AT91SAM9263, AT91SAM9RL, AT91CAP9, and the new 400MHz version with 32KB instruction and data caches, the AT91SAM9G20.