intro(9) [osx man page]

INTRO(9)						   BSD Kernel Developer's Manual						  INTRO(9)

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 isn't a question of just
     shutting up cc, it is a question about avoiding the things it complains about.  To put it bluntly, don't 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 isn't generally applied though.

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

     We don't 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 don't add new internal interfaces to the kernel, the entire source should be in one file if possi-
     ble.  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.

BSD
								 December 13, 1995							       BSD

DDB(8)							    BSD System Manager's Manual 						    DDB(8)

NAME

     ddb -- configure DDB kernel debugger properties

SYNOPSIS

     ddb capture [-M -core] [-N -system] print
     ddb capture [-M -core] [-N -system] status
     ddb script scriptname
     ddb script scriptname=script
     ddb scripts
     ddb unscript scriptname
     ddb pathname

DESCRIPTION

     The ddb utility configures certain aspects of the ddb(4) kernel debugger from user space that are not configured at compile-time or easily
     via sysctl(8) MIB entries.

     To ease configuration, commands can be put in a file which is processed using ddb as shown in the last synopsis line.  An absolute pathname
     must be used.  The file will be read line by line and applied as arguments to the ddb utility.  Whitespace at the beginning of lines will be
     ignored as will lines where the first non-whitespace character is '#'.

OUTPUT CAPTURE

     The ddb utility can be used to extract the contents of the ddb(4) output capture buffer of the current live kernel, or from the crash dump of
     a kernel on disk.	The following debugger commands are available from the command line:

     capture [-M core] [-N system] print
	     Print the current contents of the ddb(4) output capture buffer.

     capture [-M core] [-N system] status
	     Print the current status of the ddb(4) output capture buffer.

SCRIPTING

     The ddb utility can be used to configure aspects of ddb(4) scripting from user space; scripting support is described in more detail in
     ddb(4).  Each of the debugger commands is available from the command line:

     script scriptname
	     Print the script named scriptname.

     script scriptname=script
	     Define a script named scriptname.	As many scripts contain characters interpreted in special ways by the shell, it is advisable to
	     enclose script in quotes.

     scripts
	     List currently defined scripts.

     unscript scriptname
	     Delete the script named scriptname.

EXIT STATUS

     The ddb utility exits 0 on success, and >0 if an error occurs.

EXAMPLES

     The following example defines a script that will execute when the kernel debugger is entered as a result of a break signal:

	   ddb script kdb.enter.break="show pcpu; bt"

     The following example will delete the script:

	   ddb unscript kdb.enter.break

     For further examples, see the ddb(4) and textdump(4) manual pages.

SEE ALSO

     ddb(4), textdump(4), sysctl(8)

HISTORY

     The ddb utility first appeared in FreeBSD 7.1.

AUTHORS

     Robert N M Watson

BUGS

     Ideally, ddb would not exist, as all pertinent aspects of ddb(4) could be configured directly via sysctl(8).

BSD
								 December 24, 2008							       BSD