Code Coverage

Prerequisites

You need

• The code coverage patch for coreboot: http://review.coreboot.org/#/c/2052/
• The latest version of lcov: http://ltp.cvs.sourceforge.net/viewvc/ltp/utils/analysis/lcov/?view=tar

Getting started

• Install lcov. You will need to patch geninfo to make it work with the coreboot toolchain:

--- bin/geninfo	2012-11-13 01:58:53.000000000 -0800
+++ bin/geninfo	2013-01-08 16:44:48.041362229 -0800
@@ -1871,7 +1871,7 @@
 	close(GCOV_PIPE);
 
 	$result = 0;
-	if ($version_string =~ /(\d+)\.(\d+)(\.(\d+))?/)
+	if ($version_string =~ /(\d+)\.(\d+)(\.(\d+))$/)
 	{
 		if (defined($4))
 		{

Getting code coverage information

• Compile coreboot with CONFIG_COVERAGE enabled
• Flash and run coreboot on the target system
• Run cbmem on the target system to extract coverage data (see coreboot/util/cbmem/)

$ sudo ./cbmem -CV

• Transfer the files back to your host system
• Run lcov and genhtml on the host system

$ lcov --capture --directory $( pwd ) --output-file coreboot.info --gcov-tool i386-elf-gcov
$ genhtml coreboot.info --output-directory coreboot-coverage

• Find your html files visualizing code coverage in coreboot-coverage

Demo

http://www.coreboot.org/~stepan/coreboot-coverage/

See Also

• http://ltp.sourceforge.net/coverage/lcov.php
• http://gcc.gnu.org/onlinedocs/gcc/Gcov.html