an may utilize the api 30 to convert the document 12 a to representative data thereof in a specific intermediate format and the device driver further establishes a configuration tree corresponding to the document 12 a from the representative data a process is a program in execution by the processor 10 and may comprise an executed application or kernel with reference to fig7 when a first process in the electronic device system 200 is to establish a configuration tree the process invokes a tree establishing function in the api 30 step 700 the invocation comprises a filename of the device file 36 corresponding to the device driver 34 the tree establishing function acts as a parser module to parse the document 12 a and generate representative data comprising parameter values and parameter relationships recorded in the document 12 a in response to the invocation from the process step 702 the attribute u201c autoscan u201d and the value thereof in the tag lt protocol gt may be for example represented by u201c protocol autoscan enable u201d in the representative data in step 702 the tree establishing function further transfers the filename of the device file 36 the representative data and other required data to the kernel 13 through a system call 32 provided by the os of the electronic device system 200 step 704 the kernel 13 retrieves the device file 36 based on the filename subsequently retrieves the device driver 34.