Using 2.6.x kernel build system.
make: Entering directory `/tmp/vmware-config2/vmmon-only'
make -C /lib/modules/2.6.20/build/include/.. SUBDIRS=$PWD SRCROOT=$PWD/. modules
make[1]: Entering directory `/usr/src/linux-2.6.20-2'
  CC [M]  /tmp/vmware-config2/vmmon-only/linux/driver.o
In file included from /tmp/vmware-config2/vmmon-only/linux/driver.c:80:
/tmp/vmware-config2/vmmon-only/./include/compat_kernel.h:21: error: syntax error before "compat_exit"
/tmp/vmware-config2/vmmon-only/./include/compat_kernel.h:21: warning: type defaults to `int' in declaration of `_syscall1'
/tmp/vmware-config2/vmmon-only/./include/compat_kernel.h:21: warning: function declaration isn't a prototype
/tmp/vmware-config2/vmmon-only/./include/compat_kernel.h:21: warning: '_syscall1' declared `static' but never defined
make[2]: *** [/tmp/vmware-config2/vmmon-only/linux/driver.o] Error 1
make[1]: *** [_module_/tmp/vmware-config2/vmmon-only] Error 2
make[1]: Leaving directory `/usr/src/linux-2.6.20-2'
make: *** [vmmon.ko] Error 2
make: Leaving directory `/tmp/vmware-config2/vmmon-only'
Unable to build the vmmon module.

For more information on how to troubleshoot module-related problems, please 
visit our Web site at "http://www.vmware.com/download/modules/modules.html" and
"http://www.vmware.com/support/reference/linux/prebuilt_modules_linux.html".

Execution aborted.