如何在kernel模块中使用已经编译好的obj文件

最新推荐文章于 2022-07-30 11:50:17 发布

最新推荐文章于 2022-07-30 11:50:17 发布 · 505 阅读

文章标签：

#shell

本文介绍了如何在Linux内核环境下自制obj文件，并将其用于特定的内核模块中。通过在正确的编译环境下生成带有_shipped后缀的obj文件，然后在模块中正确引用该文件，实现了自定义功能的加入。

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