The command "depmod -a" resolves unsresolved symbols, because the command didn't find the current System.map. The Proble discovers when installing svgalib_helper.o. A modules-updates produced a unresolved symbols output, because this scripts uses "depmod -a". A "depmod -a -F /usr/src/linux-$(uname -r)/System.map" workds fine => no error messages. The solution for this problem is a detection of the current System.map:
- /boot/System-$(uname -r).map - /usr/src/linux-$(uname -r)/System.map - /boot/System.map - /usr/src/linux/System.map aso. and changing "depmod -a" into "depmod -a -F ${detectedSystemMap}"
works fine here.