diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/new-applet-HOWTO.txt | 74 |
1 files changed, 52 insertions, 22 deletions
diff --git a/docs/new-applet-HOWTO.txt b/docs/new-applet-HOWTO.txt index b1e1035..5d8fbe7 100644 --- a/docs/new-applet-HOWTO.txt +++ b/docs/new-applet-HOWTO.txt @@ -6,7 +6,10 @@ This document details the steps you must take to add a new applet to BusyBox. Credits: Matt Kraai - initial writeup Mark Whitley - the remix -Thomas Lundquist - Added stuff for the new directory layout. +Thomas Lundquist - Trying to keep it updated. + +When doing this you should consider using the latest svn trunk. +This is a good thing if you plan to getting it commited into mainline. Initial Write ------------- @@ -21,6 +24,10 @@ the bb_config.h and appropriate platform specific files are included properly. For a new applet mu, here is the code that would go in mu.c: +(busybox.h already includes most usual header files. You do not need +#include <stdio.h> etc...) + + ----begin example code------ /* vi: set sw=4 ts=4: */ @@ -33,7 +40,7 @@ For a new applet mu, here is the code that would go in mu.c: */ #include "busybox.h" -#include <other.h> +#include "other.h" int mu_main(int argc, char **argv); int mu_main(int argc, char **argv) @@ -69,6 +76,38 @@ useful functions in libbb. Use these instead of reinventing the wheel. Additionally, if you have any useful, general-purpose functions in your applet that could be useful in other applets, consider putting them in libbb. +And it may be possible that some of the other applets uses functions you +could use. If so, you have to rip the function out of the applet and make +a libbb function out of it. + +Adding a libbb function: +------------------------ + +Make a new file named <function_name>.c + +----start example code------ + +#include "libbb.h" +#include "other.h" + +int function(char *a) +{ + return *a; +} + +----end example code------ + +Add <function_name>.o in the right alphabetically sorted place +in libbb/Kbuild. You should look at the conditional part of +libbb/Kbuild aswell. + +You should also try to find a suitable place in include/libbb.h for +the function declaration. If not, add it somewhere anyway, with or without +ifdefs to include or not. + +You can look at libbb/Config.in and try to find out if the function is +tuneable and add it there if it is. + Placement / Directory --------------------- @@ -78,9 +117,9 @@ Find the appropriate directory for your new applet. Make sure you find the appropriate places in the files, the applets are sorted alphabetically. -Add the applet to Makefile.in in the chosen directory: +Add the applet to Kbuild in the chosen directory: -obj-$(CONFIG_MU) += mu.o +lib-$(CONFIG_MU) += mu.o Add the applet to Config.in in the chosen directory: @@ -119,31 +158,22 @@ Next, add an entry to include/applets.h. Be *sure* to keep the list in alphabetical order, or else it will break the binary-search lookup algorithm in busybox.c and the Gods of BusyBox smite you. Yea, verily: +Be sure to read the top of applets.h before adding your applet. + /* all programs above here are alphabetically "less than" 'mu' */ - #ifdef CONFIG_MU - APPLET("mu", mu_main, _BB_DIR_USR_BIN, mu_usage) - #endif + USE_MU(APPLET(mu, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) /* all programs below here are alphabetically "greater than" 'mu' */ -Documentation -------------- - -If you're feeling especially nice, you should also document your applet in the -docs directory (but nobody ever does that). - -Adding some text to docs/Configure.help is a nice start. - - The Grand Announcement ---------------------- -Then create a diff -urN of the files you added and/or modified. Typically: - <appletdir>/<applet>.c - include/usage.c - include/applets.h - <appletdir>/Makefile.in - <appletdir>/config.in +Then create a diff by adding the new files with svn (remember your libbb files) + svn add <where you put it>/mu.c +eventually also: + svn add libbb/function.c +then + svn diff and send it to the mailing list: busybox@busybox.net http://busybox.net/mailman/listinfo/busybox |