ARM架构下内核模块的交叉编译

Question

我正在尝试从linux x86机器上为ARM创建一个.ko文件。我尝试了以下Makefile：

1 obj-m +=helloworldtest_module.o 
2 modules_install:
3     make ARCH=$(ARCH) CC=$(CROSS_COMPILER) -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
4 clean:
5     make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

..。但我在命令提示符中输入make -f Makefile ARCH=arm CROSS_COMPILER=arm-linux-gnueabi-gcc时出错，如下所示：

make ARCH=arm CC=arm-linux-gnueabi-gcc -C /lib/modules/3.2.0-29-generic/build M=/home/terenesas/sample modules
make[1]: Entering directory `/usr/src/linux-headers-3.2.0-29-generic'
  CC [M]  /home/terenesas/sample/helloworldtest_module.o
In file included from /usr/src/linux-headers-3.2.0-29-generic/arch/arm/include/asm/types.h:4:0,
                 from include/linux/types.h:4,
                 from include/linux/list.h:4,
                 from include/linux/module.h:9,
                 from /home/terenesas/sample/helloworldtest_module.c:2:
include/asm-generic/int-ll64.h:11:29: fatal error: asm/bitsperlong.h: No such file or directory
compilation terminated.
make[2]: *** [/home/terenesas/sample/helloworldtest_module.o] Error 1
make[1]: *** [_module_/home/terenesas/sample] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-3.2.0-29-generic'
make: *** [modules_install] Error 2

我做错什么了？

Answer 1

快速修复，更改为：

#include <asm/bitsperlong.h>

至：

#include <asm-generic/bitsperlong.h>

Answer 2

shell uname -r意味着这个Makefile将为您的主机(X86)系统而不是ARM构建模块。

您需要指定ARM内核的源目录。你可以使用下面的Makefile来交叉编译你的模块。

Makefile：

CC=$(CROSS_COMPILE)gcc
# If KERNELRELEASE is defined, we've been invoked from the
# kernel build system and can use its language.
ifneq ($(KERNELRELEASE),)
    obj-m := modulename.o 

# Otherwise we were called directly from the command
# line; invoke the kernel build system.
else

    KERNELDIR ?= /path/to/kernel/linux
    PWD  := $(shell pwd)

default:
    ${MAKE} -C ${KERNEL_SOURCE} SUBDIRS=${PWD} modules

clean:
    ${MAKE} -C ${KERNEL_SOURCE} SUBDIRS=${PWD} clean
endif