makefile - Setting CFLAGS for pr_debug and printk -
i trying understand linux kernel module , see output of pr_debug , printk . using gnu make. understand pr_debug messages, have use ddebug . so, how enable printk statements ? lets filename kvm.c . difference between these two: cflags_kvm.o := -ddebug cflags_kvm.o += -ddebug what statement do: cflags_kvm.o := -i. [edit]: looks usage of square brackets has caused confusion. [filename], meant file, kvm.c. i don't know how activate printk() - did search google? amongst other things, found this seems imply printk() available (but have mark messages appropriate level, , there control on levels displayed on console). the square brackets in macro name unorthodox - , therefore extension specific system. reading between lines, talking linux kernel , therefore gnu make, you'd if stated such things. the := notation immediate assignment variable. rhs evaluated when line read , processed, not when macro used case. means if th...