makefile 问题请教

dada199

下面是我的一个实验要用到的Makefile文件,  但是我看不懂, 哪位能帮我讲解一下各行的功能用途吧

#
# Makefile for the linux kernel.
#
# Note! Dependencies are done automagically by 'make dep', which also
# removes any old dependencies. DON'T put your own dependencies here
# unless it's something special (ie not a .c file).
#
# Note 2! The CFLAGS definitions are now in the main makefile...

.S.s:
        $(CPP) -traditional $< -o $*.s

O_TARGET := kernel.o
O_OBJS    = sched.o dma.o fork.o exec_domain.o panic.o printk.o sys.o \
            module.o exit.o itimer.o info.o time.o softirq.o resource.o \
            sysctl.o acct.o capability.o event.o

OX_OBJS  += signal.o

ifeq ($(CONFIG_KMOD),y)
O_OBJS += kmod.o
endif

ifeq ($(CONFIG_MODULES),y)
OX_OBJS  += ksyms.o
endif

CFLAGS_sched.o := $(PROFILING) -fno-omit-frame-pointer

include $(TOPDIR)/Rules.make


其中的event.o 是要加进内核中的, 是一个同步机制的实现. 这个文件可能要替换源码中的某个文件,用来编译内核,从而把机制加进内核,
恳请高人指点一二......不胜感激

Tetris

和shell编程差不多吧。

gamebo

ifdef SUBDIRS
如果定义了SUBDIRS

KBUILD_EXTMOD ?= $(SUBDIRS)如果KBUILD_EXTMOD的值没被定义过，那么变量KBUILD_EXTMOD的值就是$(SUBDIRS)

dada199

还请高人赐教