Abstract

RTLinux has been focused on developing a POSIX compliant RTOS layer that operates below Linux – within this development communication between RT-threads and kernel as well as user-space have been quite limited, in part due to the inherent restrictions of a RTOS and in part due to the restrictions imposed by POSIX, or rather the combination of these two sets of restrictions. As RT-threads are operating in the same address-space as the Linux kernel itself it seems natural to investigate what capabilities within the Linux kernel could be made available to RT-threads as to enhance communication paths too and from user-space and non-rt kernel-space. In this paper a few of these, very non-portable, absolutely non-POSIX, paths are described. The main resources of interest to RT-threads being: Tasklets, Kernel Threads, Software interrupts, Global Variables. Accessing Non-RT facilities in kernel space Presenting a few simple examples the mechanisms and problems with utilizing these capabilities of the Linux kernel from within RT-context are discussed.

Read full paper (PDF download)

 
This article was originally published on LinuxDevices.com and has been donated to the open source community by QuinStreet Inc. Please visit LinuxToday.com for up-to-date news and articles about Linux and open source.