Linux 驱动-1 Hello World

1. Hello.c

优先级低于3的才被打印

---

hello.c

---

#include

#include <linux/module.h>

MODULE_LICENSE("GPL");

MODULE_AUTHOR("PD");

static int hello_init(void)

{

printk(KERN_SOH"hello_init \n");

return 0;

}

static void hello_exit(void)

{

printk("hello_exit \n");

return;

}

module_init(hello_init); //insmod

module_exit(hello_exit);//rmmod

---

Makefile

---

ifneq ($(KERNELRELEASE),)

obj-m:=hello.o

else

KDIR :=/lib/modules/$(shell uname -r)/build

PWD  :=$(shell pwd)

all:

make -C $(KDIR) M=$(PWD) modules

clean:

rm -f *.ko *.o *.mod.o *.symvers *.cmd  *.mod.c *.order

endif

---

Log

---

w@w:~/linux_kernel/hello$ ls

hello.c  Makefile

w@w:~/linux_kernel/hello$ sudo make

make -C /lib/modules/5.4.0-104-generic/build M=/home/w/linux_kernel/hello modules

make[1]: Entering directory '/usr/src/linux-headers-5.4.0-104-generic'

  CC [M]  /home/w/linux_kernel/hello/hello.o

  Building modules, stage 2.

  MODPOST 1 modules

  CC [M]  /home/w/linux_kernel/hello/hello.mod.o

  LD [M]  /home/w/linux_kernel/hello/hello.ko

make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-104-generic'

w@w:~/linux_kernel/hello$ ls

hello.c  hello.mod    hello.mod.o  Makefile      Module.symvers

hello.kohello.mod.c  hello.o      modules.order

w@w:~/linux_kernel/hello$ sudo insmod hello.ko

w@w:~/linux_kernel/hello$ sudo lsmod

Module                  Size  Used by

hello                  16384  0

w@w:~/linux_kernel/hello$ dmesg

[  549.186132] �hello_init

w@w:~/linux_kernel/hello$ sudo rmmod hello.ko

w@w:~/linux_kernel/hello$ dmesg

[  549.186132] �hello_init

[  584.376325] hello_exit

w@w:~/linux_kernel/hello$ lsmod

Module                  Size  Used by