1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)intro.8 8.2 (Berkeley) 12/11/93 33.\" 34.Dd December 13, 1995 35.Dt INTRO 9 36.Os FreeBSD 2.2 37.Sh NAME 38.Nm intro 39.Nd "introduction to system kernel interfaces" 40.Sh DESCRIPTION 41This section contains information about the interfaces and 42subroutines in the kernel. 43 44.Sh PROTOTYPES ANSI-C AND ALL THAT 45Yes please. 46 47We would like all code to be fully prototyped. 48 49If your code compiles cleanly with 50.Nm cc 51.Ar -Wall 52we would feel happy about it. 53It is important to understand that this isn't a question of just shutting up 54.Nm cc , 55it is a question about avoiding the things it complains about. 56To put it bluntly, don't hide the problem by casting and other 57obfuscating practices, solve the problem. 58 59.Sh INDENTATION AND STYLE 60Belive it or not, there actually exists a guide for indentation and style. 61It isn't generally applied though. 62 63We would appreciate if people would pay attention to it, and at least not 64violate it blatantly. 65 66We don't mind it too badly if you have your own style, but please make 67sure we can read it too. 68 69In particular there are some iron-clad requirements: 70.Bl -enum -compact 71.It 72TAB stops is 8. 73.It 74All funtion names start in col 1. 75.El 76 77.Sh NAMING THINGS 78Some general rules exist: 79.Bl -enum 80.It 81If a function is meant as a debugging aid in DDB, it should be enclosed 82in 83.Bd -literal -offset indent 84#ifdef DDB 85 86#endif /* DDB */ 87.Ed 88 89And the name of the procedure shoule start with the prefix 90.Li DDB_ 91to clearly identify the procedure as a debugger routine. 92.El 93 94 95.Sh SCOPE OF SYMBOLS 96It is important to carefully consider the scope of symbols in the kernel. 97The default is to make everything static, unless some reason requires 98the opposite. 99 100There are several reasons for this policy, 101the main one is that the kernel is one monolithic name-space, 102and polution is not a good idea here either. 103 104For device drivers and other modules that don't add new internal interfaces 105to the kernel, the entire source should be in one file it possible. 106That way all symbols can be made static. 107 108If for some reason a module is split over multiple source files, then try 109to split the module along some major fault-line and consider using the 110number of global symbols as your guide. 111The fewer the better. 112 113.Sh HISTORY 114The 115.Nm intro 116section manual page appeared in FreeBSD 2.2 117