Coverage and Profiling for Real-Time Tiny Kernels

Real-time tiny kernels run on the embedded devices with limited resources (especially memory) and usually with no file system. How theses real-time tiny kernels can be enhanced to enable coverage and profiling for the applications running in them using gcov and gprof tool provided by GCC has been described in this paper. The changes made in gcc-tool-chain in order to separate the gprof tool (based on version glibc 2.8 and binutils 2.18.50) so that it can be used for any target architecture and for any real-time OS without file system has been described here. Furthermore, when an application is enabled for coverage or profiling, its memory footprint as well as the execution time increases significantly. Due to the stringent memory constraint on embedded devices, it is necessary to keep the memory footprint of the running applications as small as possible. Hence, in this paper, a feature called function level coverage and profiling is described, which can be used to reduce the memory footprint and the execution time for coverage and profiling enabled applications. The above mentioned feature is incorporated in GCC (version 4.3) and the changes required in gcc-tool-chain to implement the feature have been described. Function level coverage and profiling feature was tested on arm target board with uC/OS-II RTOS and results show that it can save significant amount of memory on target board as well as it can reduce the execution time of the coverage/profiling enabled applications.