编译内核模块常见问题

        在x86上做出来了，但是在ARM上却出现了很多问题，有内核代码准备的问题，有模块代码问题，也有Makefile的问题。看似不起眼的角色，出了问题也很纠结。

第一种：内核代码没有准备好

[root@localhost module]# make make -C /opt/kangear/kernel/linux-2.6.32.2 M=/root/桌面/kangear/module modulesmake[1]: Entering directory `/opt/kangear/kernel/linux-2.6.32.2'  ERROR: Kernel configuration is invalid.         include/linux/autoconf.h or include/config/auto.conf are missing.         Run 'make oldconfig && make prepare' on kernel src to fix it.  WARNING: Symbol version dump /opt/kangear/kernel/linux-2.6.32.2/Module.symvers           is missing; modules will have no dependencies and modversions.  Building modules, stage 2./opt/kangear/kernel/linux-2.6.32.2/scripts/Makefile.modpost:42: include/config/auto.conf: 没有那个文件或目录make[2]: *** 没有规则可以创建目标“include/config/auto.conf”。 停止。make[1]: *** [modules] 错误 2make[1]: Leaving directory `/opt/kangear/kernel/linux-2.6.32.2'make: *** [all] 错误 2[root@localhost module]# 

        这种是下载的很干净的内核，配置都没有配置；或是配置了，有.config但是没有make zImage。编译一下，不为用这个zImage,只是为了更好的编译内核模块。

        其实看实质就是找不到auto.conf，这个其实已经有了，就是.config，但是如果不想手动来拷贝可以假装make zImage（如下），这里就可以了，完整的编译一个内核只为了这个一个配置文件，也太浪费了。

[root@localhost linux-2.6.32.2]# make zImage  HOSTLD  scripts/kconfig/confscripts/kconfig/conf -s arch/arm/Kconfig  CHK     include/linux/version.h  UPD     include/linux/version.h  Generating include/asm-arm/mach-types.h  CHK     include/linux/utsrelease.h  UPD     include/linux/utsrelease.h  SYMLINK include/asm -> include/asm-arm  CC      kernel/bounds.s  GEN     include/linux/bounds.h  CC      arch/arm/kernel/asm-offsets.s  GEN     include/asm/asm-offsets.h  CALL    scripts/checksyscalls.sh  CC      scripts/mod/empty.o  HOSTCC  scripts/mod/mk_elfconfig  MKELF   scripts/mod/elfconfig.h  HOSTCC  scripts/mod/file2alias.o  HOSTCC  scripts/mod/modpost.o  HOSTCC  scripts/mod/sumversion.o  HOSTLD  scripts/mod/modpost  HOSTCC  scripts/kallsyms  HOSTCC  scripts/pnmtologo  HOSTCC  scripts/conmakehash  CC      init/main.o  CHK     include/linux/compile.h  UPD     include/linux/compile.h  CC      init/version.o^Cmake[1]: *** wait: 没有子进程。 停止。make[1]: *** 正在等待未完成的任务....make[1]: *** wait: 没有子进程。 停止。make: *** wait: 没有子进程。 停止。make: *** 正在等待未完成的任务....make: *** wait: 没有子进程。 停止。[root@localhost linux-2.6.32.2]# 

        这里再来make一下：

[root@localhost module]# makemake -C /opt/kangear/kernel/linux-2.6.32.2 M=/root/桌面/kangear/module modulesmake[1]: Entering directory `/opt/kangear/kernel/linux-2.6.32.2'  WARNING: Symbol version dump /opt/kangear/kernel/linux-2.6.32.2/Module.symvers           is missing; modules will have no dependencies and modversions.  CC [M]  /root/桌面/kangear/module/hello.o  Building modules, stage 2.  MODPOST 1 modulesWARNING: modpost: missing MODULE_LICENSE() in /root/桌面/kangear/module/hello.osee include/linux/module.h for more information  CC      /root/桌面/kangear/module/hello.mod.o  LD [M]  /root/桌面/kangear/module/hello.komake[1]: Leaving directory `/opt/kangear/kernel/linux-2.6.32.2'[root@localhost module]# lshello.c   hello.mod.c  hello.o   modules.order   paramhello.ko  hello.mod.o  Makefile  Module.symvers  symbol[root@localhost module]# 

        注意看hello.ko就出来了。

第二种错误：模块代码有异常

[root@localhost hello]# makemake -C /opt/kangear/kernel/linux-2.6.32.2 M=/opt/kangear/hello  modulesmake[1]: Entering directory `/opt/kangear/kernel/linux-2.6.32.2'  WARNING: Symbol version dump /opt/kangear/kernel/linux-2.6.32.2/Module.symvers           is missing; modules will have no dependencies and modversions.  CC [M]  /opt/kangear/hello/hello.o/opt/kangear/hello/hello.c:3: error: expected declaration specifiers or '...' before string constant/opt/kangear/hello/hello.c:3: warning: data definition has no type or storage class/opt/kangear/hello/hello.c:3: warning: type defaults to 'int' in declaration of 'MODULE_LECENSE'/opt/kangear/hello/hello.c:3: warning: function declaration isn't a prototype/opt/kangear/hello/hello.c:17: error: redefinition of '__inittest'/opt/kangear/hello/hello.c:16: note: previous definition of '__inittest' was here/opt/kangear/hello/hello.c: In function '__inittest':/opt/kangear/hello/hello.c:17: warning: return from incompatible pointer type/opt/kangear/hello/hello.c: At top level:/opt/kangear/hello/hello.c:17: error: redefinition of 'init_module'/opt/kangear/hello/hello.c:16: note: previous definition of 'init_module' was heremake[2]: *** [/opt/kangear/hello/hello.o] 错误 1make[1]: *** [_module_/opt/kangear/hello] 错误 2make[1]: Leaving directory `/opt/kangear/kernel/linux-2.6.32.2'make: *** [default] 错误 2[root@localhost hello]# make

        这大多是模块代码的错误，里边有中文相关的一些东西了，一些符号。代码是在博客上拷贝的或者是在win下用ue编辑的，直接拷贝到Linux中就会有这种问题。唯一的办法就是重新打一编代码了。目前还没有找到合适的方法。（语法问题就不提了）

第三种：模块Makefile语法错误

[root@localhost hello]# makemake: Nothing to be done for `default'.[root@localhost hello]# 

        对应的makefile是命令为：

default:make -C $(KERNELDIR) M=$(PWD)  modules

        make前边应该有一个tab键。或者是make前边是空格而不是tab。