Diff and patch commands

Diff and patch command 1: if the current directory contains the linux-3.0 source directory file and the modified linux-3.0-s3c2440 directory file, how to generate the patch file? >>> Diff-Nuar linux-3.0 linux-3.0> linux-3.0-s3c2440.patch to generate linux-3.0-s3c2440.patch files. Second: if there is a modified linux-3.0-s3c2440 directory files and linux-3.0-s3c2440.patch files under the current directory, how to generate source linux-3.0 source directory files? >>>> Patch-RE-p0 <linux-3.0-s3c2440.patch> mv linux-3.0-s3c2440 linux-3.0 can generate linux-3.0 source directory file third: if the current directory has linux-3.0 source directory file and linux-3.0-s3c2440.patch file, how do I generate a modified linux-3.0-s3c2440 directory file? >>> Patch-p0 <linux-3.0-s3c2440.patch> mv linux-3.0 linux-3.0-s3c2440 linux-3.0-s3c2440 can generate directory files