交叉编译linux驱动程序

1,获取源码odroid开发板内核源码(已经打了preempt_rt-3.14.79-rt84实时补丁),并编译内核和驱动模块,并安装驱动模块:

      $cd ~/odroid_c2

      $git clone https://github.com/moonlinux/linux.git  -b odroidc2-3.14.y-rt

      $cd ./linux

      $make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- Image -j4

      $make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- modules -j4

      $make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- modules_install INSTALL_MOD_PATH=~/odroid_c2/modules

(编译器下载地址:https://releases.linaro.org/components/toolchain/binaries/4.9-2017.01/aarch64-linux-gnu/gcc-linaro-4.9.4-2017.01-x86_64_aarch64-linux-gnu.tar.xz)

2,编译驱动:

   $make  ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-  -j4

3,源码

驱动源码:

/* simple kernel module:hello.c

 *

 * Copyright (C) 2014 Barry Song (baohua@kernel.org)

 *

 * Licensed under GPLv2 or later.

 */

#include <linux/init.h>

#include <linux/module.h>

static int __init hello_init(void)

{

  printk(KERN_INFO "Hello World enter\n");

  return 0;

}

module_init(hello_init);

static void __exit hello_exit(void)

{

  printk(KERN_INFO "Hello World exit\n");

}

module_exit(hello_exit);

MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");

MODULE_LICENSE("GPL v2");

MODULE_DESCRIPTION("A simple Hello World Module");

MODULE_ALIAS("a simplest module");
-----------------------

Makefile文件:

#for Amlogic S905-build commond line :

#or: make  ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-  -j4

obj-m := hello.o

KDIR := /home/bruce/odroid_c2/modules/lib/modules/3.14.79-rt84+/build

KBUILD_CFLAGS +=  -march=armv8-a -mtune=cortex-a53

MAKE := make

build: kernel_modules

kernel_modules:

        ${MAKE} -C $(KDIR) M=$(PWD) modules

.PHONY: clean

clean:

        ${MAKE} -C $(KDIR) M=$(PWD) clean