将DM9000驱动编译进内核，make zImage编译成功。
但是，将DM9000驱动作为模块，make zImage成功后，make modules出现以下信息：
CHK include/linux/version.h
make[1] : 'arch/arm/kernel/asm-offsets.s ' is up to date.
CHK include/asm-arm/constants.h
make[1] : 'include/asm-arm/mach-types.h' is up to date.
CC[M] drivers/net/dm9000x.o
drivers/net/dm9000.c : In function 'dmfe_probe' :
drivers/net/dm9000.c : 288 : warning : assingment makes integer from pointer without a cast
drivers/net/dm9000.c : In function 'init_module' :
drivers/net/dm9000.c : 1107 : error : 'dmfe_debug' undeclared (first use in this function)
drivers/net/dm9000.c : 1107 : error : (Each undeclared identifier is reported only once
drivers/net/dm9000.c : 1107 : error : for each function it appears in.)
make[2] : ***[drivers/net/dm9000x.o] Error 1
make[1] : ***[drivers/net] Error 2
make : ***[drivers] Error 2
可以成功编进内核却不能成功编成模块，不解？？？
