我正在尝试在 beaglebone (ARM) 上为 3.8.13 编译一个简单的“hello world”内核模块：
你好ç：
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
void init_module(void)
{
printk(KERN_INFO "My Kernel Module is enabled.\n");
return 0;
}
void cleanup_module(void)
{
printk(KERN_INFO "My Kernel Module is disabled.\n");
}
无论我尝试什么，我总是得到
In file included from /home/root/src/moduletest/hello.c:1:0:
./include/linux/init.h:159:1: error: unknown type name 'bool'
我已经尝试重新安装 kernel-dev、kernel-headers、“make headers_install”，但没有运气，并且正在运行想法。
这是生成文件：
obj-m += hello.o
KDIR = /usr/src/kernel
PWD := $(shell pwd)
all:
make -C $(KDIR) M=$(PWD) modules
clean:
make -C $(KDIR) M=$(PWD) clean
以及make的完整输出：
root@beaglebone:~/src/moduletest# make
make -C /usr/src/kernel M=/home/root/src/moduletest modules
make[1]: Entering directory `/usr/src/kernel'
CC [M] /home/root/src/moduletest/hello.o
In file included from /home/root/src/moduletest/hello.c:1:0:
./include/linux/init.h:159:1: error: unknown type name 'bool'
/home/root/src/moduletest/hello.c: In function 'init_module':
/home/root/src/moduletest/hello.c:7:9: error: implicit declaration of function 'printk' [-Werror=implicit-function-declaration]
/home/root/src/moduletest/hello.c:7:16: error: 'KERN_INFO' undeclared (first use in this function)
/home/root/src/moduletest/hello.c:7:16: note: each undeclared identifier is reported only once for each function it appears in
/home/root/src/moduletest/hello.c:7:26: error: expected ')' before string constant
/home/root/src/moduletest/hello.c:8:9: warning: 'return' with a value, in function returning void [enabled by default]
/home/root/src/moduletest/hello.c: In function 'cleanup_module':
/home/root/src/moduletest/hello.c:13:16: error: 'KERN_INFO' undeclared (first use in this function)
/home/root/src/moduletest/hello.c:13:26: error: expected ')' before string constant
cc1: some warnings being treated as errors
make[2]: *** [/home/root/src/moduletest/hello.o] Error 1
make[1]: *** [_module_/home/root/src/moduletest] Error 2
make[1]: Leaving directory `/usr/src/kernel'
make: *** [all] Error 2
编辑：
看来 gcc 使用用户空间 uapi/linux/types.h 标头而不是 linux/types.h。添加 gcc -v -H 显示
GNU C (Linaro GCC 4.7-2013.02-01) version 4.7.3 20130205 (prerelease) (arm-angstrom-linux-gnueabi)
compiled by GNU C version 4.7.3 20130205 (prerelease), GMP version 5.0.5, MPFR version 3.1.0, MPC version 0.8.2
GGC heuristics: --param ggc-min-expand=64 --param ggc-min-heapsize=63851
ignoring duplicate directory "/usr/src/kernel/include"
ignoring duplicate directory "include"
as it is a non-system directory that duplicates a system directory
#include "..." search starts here:
#include <...> search starts here:
/usr/src/kernel/arch/arm/include
arch/arm/include/generated
/usr/src/kernel/arch/arm/include/uapi
arch/arm/include/generated/uapi
/usr/src/kernel/include/uapi
include/generated/uapi
arch/arm/mach-omap2/include
arch/arm/plat-omap/include
./include <-------- this refers to /usr/src/kernel/include and should be above the "uapi" line
End of search list.
这包括树：
. ./include/linux/init.h
.. ./include/linux/compiler.h
... ./include/linux/compiler-gcc.h
.... ./include/linux/compiler-gcc4.h
.. /usr/src/kernel/include/uapi/linux/types.h
... arch/arm/include/generated/asm/types.h
.... /usr/src/kernel/include/uapi/asm-generic/types.h
..... /usr/src/kernel/include/uapi/asm-generic/int-ll64.h
...... arch/arm/include/generated/asm/bitsperlong.h
....... /usr/src/kernel/include/uapi/asm-generic/bitsperlong.h
... /usr/src/kernel/include/uapi/linux/posix_types.h
.... /usr/src/kernel/include/uapi/linux/stddef.h
.... /usr/src/kernel/arch/arm/include/uapi/asm/posix_types.h
..... /usr/src/kernel/include/uapi/asm-generic/posix_types.h
...... arch/arm/include/generated/asm/bitsperlong.h
In file included from /home/root/src/moduletest/hello.c:8:0:
./include/linux/init.h:159:1: error: unknown type name 'bool'
. /usr/src/kernel/include/uapi/linux/module.h
. /usr/src/kernel/include/uapi/linux/kernel.h
.. /usr/src/kernel/include/uapi/linux/sysinfo.h
我不知道它为什么这样做。添加 -I /usr/src/kernel/include 不起作用，因为它被假定为系统目录，因此被放在包含路径列表的末尾。