如何在kernel模块中使用已经编译好的obj文件

这也是一时心血来潮，觉得好玩。 在Document/kbuild/modules.txt中看到这么一段

--- 3.3 Binary Blobs

Some external modules need to include an object file as a blob.

kbuild has support for this, but requires the blob file to be

named <filename>_shipped. When the kbuild rules kick in, a copy

of <filename>_shipped is created with _shipped stripped off,

giving us <filename>. This shortened filename can be used in

the assignment to the module.

Throughout this section, 8123_bin.o_shipped has been used to

build the kernel module 8123.ko; it has been included as

8123_bin.o.

8123-y := 8123_if.o 8123_pci.o 8123_bin.o

Although there is no distinction between the ordinary source

files and the binary file, kbuild will pick up different rules

when creating the object file for the module.

想着好玩，就自己试了一下，开始不成功，后来在高手的帮助下终于成功了。

1。 创建自己的obj文件

我最开始使用 gcc -c ex_obj.c -o ex_obj.o_shipped 来做的，结果链接后不能正常工作。

原来是一定要放在编译kernel的环境中编译这个obj。网上高手说了 要这么写

ifneq ($(KERNELRELEASE),)

obj-y := xxxx.o #your obj files goes here. 关键在这里，用obj-y 来指定要编译的，然后这个过程就在编译的时候停了，不会继续链接。

else

KERNELDIR ?= /lib/modules/$(shell uname -r)/build

PWD := $(shell pwd)

default:

$(MAKE) -C $(KERNELDIR) M=$(PWD)

endif

clean:

rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions

depend .depend dep:

$(CC) $(CFLAGS) -M *.c > .depend

ifeq (.depend,$(wildcard .depend))

include .depend

endif

编译成功后，将这个拷贝到需要链接的模块目录。

记住要添加_shipped后缀

2。 然后在需要这个obj的模块中添加

scull-y := main.o pipe.o access.o ex_obj.o

然后在源代码中调用相应的函数，ok，可以了。

不过貌似没有啥实际用处。 ：）