Hi ,


We are trying to do a code coverage in Android ,  we are following the process in the gcov.txt in documentation of the sources. We are facing some issues in getting the .gcda files ,



After mounting  mount –t debugfs none /sys/debug/kernel

.gcda files are not getting generated in /sys/kernel/debug folder (only reset file is seen) no folders are available.




We are trying to follow the below process:


1.       Download the Kernel sources

2.       Go to the kernel source directory. Enable the gcov-kernel configuration options:

#make menuconfig

General setup

GCOV-based kernel profiling

select “Enable gcov-based kernel profiling”


3.       Save and Exit from Menuconfig


Modules/ Drivers


In the Makefile of the code to be covered we enable.




We are also going to the subdirectory or a dependency of driver on other files, the same needs to be added to the Makefile of those respective files/ directories


For android , we are doing a make to generate boot.tar.gz and system.tar.gz.


We flash this into a target using flashdevice.sh (Android specific) . We are able to see .gcno files in the build directory (this confirms coverage is enabled).



After boot in the target,

We do a mount –t debugfs none /sys/debug/kernel

we see there are no .gcda files in the /sys/debug/kernel folder .



Please advise me what could have went wrong or should we do something else to get a .gcda files in the /sys/debug/kernel folder.



Any pointers will be helpful.