RTLinux

RTLinux

RTLinux is a small hard real-time OS microkernel, which is having a higher priority than the Linux kernel.  The RTLinux kernel works beneath Linux. Real-time kernel executes real-time tasks such as deterministic interrupt latency ISRs and other non-real-time tasks such as in deterministic task processing are moved to Linux kernel. In RTLinux, the entire OS runs as a fully preemptive process. The Linux kernel is modified by adding a virtual machine layer in between the computer hardware and standard linux kernel. Here the Linux functions are moved to a FIFO. The FIFO memory is shared between RTLinux and Linux. In this FIFO, RTLinux programs are having higher priority and Linux functions are having lower priority. While running, real-time tasks will disable the interrupts thus reducing the unpredictability.  RTLinux requires a 4MB footprint. RTLinux supports many features such as root-level security, it prevents unauthorized port access, registering and initialization of modules as well as threads, scheduling, etc.

Programming Tips

1. RTLinux uses the kernel space for executing the programs and there will be not be any protection against errors in the user's code. Programming errors may lead to system down.

2. Use the debugger which the RTLinux supplies in order to reduce the risk of system crashes.

3. If the floating point unit is required in the task, we must explicitly set permissions, because by default RTLinux tasks are not having floating point unit access.

4. Command prompt arguments can't be passed in RTLinux.