Kernel source code of module programming

Kernel source code of module programming-Linux general technology-Linux programming and kernel information. For details, see the following. Problem: I installed fedora7 has been fully installed but/usr/src/There is no linux-2.6.20 under similar folders only a Redhat folder and the folder inside is empty obviously not the source code directory.

I did: I downloaded the linux-2.6.20 source code from www.kernel.org/pub/linux/kernel/v2.6to/usr/src/, but when I compiled it (gcc-I/usr/src/linux-2.6.20/include filename. c) prompt me/linux/init. the asm/mentioned in the H file does not exist (similar errors do not exist many times) I went to/usr/src/linux-2.6.20/include and saw that it does not exist. I think it would be because v2.4 and v2.6 are different, so the source code of v2.4 does not exist that directory.

Expected answers:
1. What platform and kernel version are generally used for module programming? Is the system source code tree ready?
2. I just learned module programming. I don't know the major prerequisites and necessary steps to ensure that compilation results can be obtained step by step from scratch before compilation. Thanks for your help.