NAME

     intro — introduction to system kernel interfaces

DESCRIPTION

     This section contains information about the interfaces and subroutines in the kernel.

PROTOTYPES ANSI-C AND ALL THAT

     Yes please.

     We would like all code to be fully prototyped.

     If your code compiles cleanly with cc -Wall we would feel happy about it.  It is important
     to understand that this is not a question of just shutting up cc, it is a question about
     avoiding the things it complains about.  To put it bluntly, do not hide the problem by
     casting and other obfuscating practices, solve the problem.

INDENTATION AND STYLE

     Believe it or not, there actually exists a guide for indentation and style.  It is not
     generally applied though.

     We would appreciate if people would pay attention to it, and at least not violate it
     blatantly.

     We do not mind it too badly if you have your own style, but please make sure we can read it
     too.

     Please take time to read style(9) for more information.

NAMING THINGS

     Some general rules exist:

     1.   If a function is meant as a debugging aid in DDB, it should be enclosed in

                #ifdef DDB

                #endif /* DDB */

          And the name of the procedure should start with the prefix DDB_ to clearly identify the
          procedure as a debugger routine.

SCOPE OF SYMBOLS

     It is important to carefully consider the scope of symbols in the kernel.  The default is to
     make everything static, unless some reason requires the opposite.

     There are several reasons for this policy, the main one is that the kernel is one monolithic
     name-space, and pollution is not a good idea here either.

     For device drivers and other modules that do not add new internal interfaces to the kernel,
     the entire source should be in one file if possible.  That way all symbols can be made
     static.

     If for some reason a module is split over multiple source files, then try to split the
     module along some major fault-line and consider using the number of global symbols as your
     guide.  The fewer the better.

SEE ALSO

     style(9)

HISTORY

     The intro section manual page appeared in FreeBSD 2.2.