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.Dd December 13, 1995 32.Dt INTRO 9 33.Os FreeBSD 2.2 34.Sh NAME 35.Nm intro 36.Nd "introduction to system kernel interfaces" 37.Sh DESCRIPTION 38This section contains information about the interfaces and 39subroutines in the kernel. 40.Sh PROTOTYPES ANSI-C AND ALL THAT 41Yes please. 42.Pp 43We would like all code to be fully prototyped. 44.Pp 45If your code compiles cleanly with 46.Nm cc 47.Ar -Wall 48we would feel happy about it. 49It is important to understand that this isn't a question of just shutting up 50.Nm cc , 51it is a question about avoiding the things it complains about. 52To put it bluntly, don't hide the problem by casting and other 53obfuscating practices, solve the problem. 54.Sh INDENTATION AND STYLE 55Belive it or not, there actually exists a guide for indentation and style. 56It isn't generally applied though. 57.Pp 58We would appreciate if people would pay attention to it, and at least not 59violate it blatantly. 60.Pp 61We don't mind it too badly if you have your own style, but please make 62sure we can read it too. 63.Pp 64Please take time to read 65.Xr style 9 66for more information. 67.Sh NAMING THINGS 68Some general rules exist: 69.Bl -enum 70.It 71If a function is meant as a debugging aid in DDB, it should be enclosed 72in 73.Bd -literal -offset indent 74#ifdef DDB 75 76#endif /* DDB */ 77.Ed 78 79And the name of the procedure should start with the prefix 80.Li DDB_ 81to clearly identify the procedure as a debugger routine. 82.El 83.Sh SCOPE OF SYMBOLS 84It is important to carefully consider the scope of symbols in the kernel. 85The default is to make everything static, unless some reason requires 86the opposite. 87.Pp 88There are several reasons for this policy, 89the main one is that the kernel is one monolithic name-space, 90and pollution is not a good idea here either. 91.Pp 92For device drivers and other modules that don't add new internal interfaces 93to the kernel, the entire source should be in one file it possible. 94That way all symbols can be made static. 95.Pp 96If for some reason a module is split over multiple source files, then try 97to split the module along some major fault-line and consider using the 98number of global symbols as your guide. 99The fewer the better. 100.Sh HISTORY 101The 102.Nm intro 103section manual page appeared in 104.Fx 2.2 . 105