1 license problem, Linux driver must have a license, use MODULE_LICENSE ( "GPL"); solve
2 to avoid "name space pollution" module dynamically linked into the kernel, it is best not to the global variable light output of the kernel, the solution: EXPORT_NO_SYMBOLS, using the contents of the file after this macro does not export any symbols, EXPORT_SYMBOLS, forced output of a symbol, static symbols may be output, it is necessary to use EXPORT_NO_SYMBOLS before use. (So-called output symbols, that is the outside of the file can be variable)
Dependence between the module 3
4 integrated into the kernel module
5 see Supported devices: cat / proc / devices
6 dmesg View startup information system
7 View device IO physical memory address: cat / proc / ioports
View No. 8 terminal in use: cat / proc / interrupt
