source: MondoRescue/branches/stable/mindi-busybox/docs/new-applet-HOWTO.txt @ 1770

Last change on this file since 1770 was 1770, checked in by Bruno Cornec, 12 years ago
  • Better output for mindi-busybox revision
  • Remove dummy file created on NFS - report from Arnaud Tiger <arnaud.tiger_at_hp.com>
  • strace useful for debug
  • fix new versions for pb (2.0.0 for mindi and 1.7.2 for mindi-busybox)
  • fix build process for mindi-busybox + options used in that version (dd for label-partitions-as-necessary)
  • fix typo in label-partitions-as-necessary which doesn't seem to work
  • Update to busybox 1.7.2
  • perl is now required at restore time to support uuid swap partitions (and will be used for many other thigs

in the future for sure)

  • next mindi version will be 2.0.0 due to all the changes made in it (udev may break working distros)
  • small optimization in mindi on keyboard handling (one single find instead of multiple)
  • better interaction for USB device when launching mindi manually
  • attempt to automatically guess block disk size for ramdisk
  • fix typos in bkphw
  • Fix the remaining problem with UUID support for swap partitions
  • Updates mondoarchive man page for USB support
  • Adds preliminary Hardware support to mindi (Proliant SSSTK)
  • Tries to add udev support also for rhel4
  • Fix UUID support which was still broken.
  • Be conservative in test for the start-nfs script
  • Update config file for mindi-busybox for 1.7.2 migration
  • Try to run around a busybox bug (1.2.2 pb on inexistant links)
  • Add build content for mindi-busybox in pb
  • Remove distributions content for mindi-busybox
  • Fix a warning on inexistant raidtab
  • Solve problem on tmpfs in restore init (Problem of inexistant symlink and busybox)
  • Create MONDO_CACHE and use it everywhere + creation at start
  • Really never try to eject a USB device
  • Fix a issue with &> usage (replaced with 1> and 2>)
  • Adds magic file to depllist in order to have file working + ldd which helps for debugging issues
  • tty modes correct to avoid sh error messages
  • Use ext3 normally and not ext2 instead
  • USB device should be corrected after reading (take 1st part)
  • Adds a mount_USB_here function derived from mount_CDROM_here
  • usb detection place before /dev detection in device name at restore time
  • Fix when restoring from USB: media is asked in interactive mode
  • Adds USB support for mondorestore
  • mount_cdrom => mount_media
  • elilo.efi is now searched throughout /boot/efi and not in a fixed place as there is no standard
  • untar-and-softlink => untar (+ interface change)
  • suppress useless softlinks creation/removal in boot process
  • avoids udevd messages on groups
  • Increase # of disks to 99 as in mindi at restore time (should be a conf file parameter)
  • skip existing big file creation
  • seems to work correctly for USB mindi boot
  • Adds group and tty link to udev conf
  • Always load usb-torage (even 2.6) to initiate USB bus discovery
  • Better printing of messages
  • Attempt to fix a bug in supporting OpenSusE 10.3 kernel for initramfs (mindi may now use multiple regex for kernel initrd detection)
  • Links were not correctly done as non relative for modules in mindi
  • exclusion of modules denied now works
  • Also create modules in their ordinary place, so that classical modprobe works + copy modules.dep
  • Fix bugs for DENY_MODS handling
  • Add device /dev/console for udev
  • ide-generic should now really be excluded
  • Fix a bug in major number for tty
  • If udev then adds modprobe/insmod to rootfs
  • tty0 is also cretaed with udev
  • ide-generic put rather in DENY_MODS
  • udevd remove from deplist s handled in mindi directly
  • better default for mindi when using --usb
  • Handles dynamically linked busybox (in case we want to use it soon ;-)
  • Adds fixed devices to create for udev
  • ide-generic should not be part of the initrd when using libata v2
  • support a dynamically linked udev (case on Ubuntu 7.10 and Mandriva 2008.0 so should be quite generic) This will give incitation to move to dyn. linked binaries in the initrd which will help for other tasks (ia6 4)
  • Improvement in udev support (do not use cl options not available in busybox)
  • Udev in mindi
    • auto creation of the right links at boot time with udev-links.conf(from Mandriva 2008.0)
    • rework startup of udev as current makes kernel crash (from Mandriva 2008.0)
    • add support for 64 bits udev
  • Try to render MyInsmod? silent at boot time
  • Adds udev support (mandatory for newest distributions to avoid remapping of devices in a different way as on the original system)
  • We also need vaft format support for USB boot
  • Adds libusual support (Ubuntu 7.10 needs it for USB)
  • Improve Ubuntu/Debian? keyboard detection and support
  • pbinit adapted to new pb (0.8.10). Filtering of docs done in it
  • Suppress some mondo warnings and errors on USB again
  • Tries to fix lack of files in deb mindi package
  • Verify should now work for USB devices
  • More log/mesages improvement for USB support
  • - Supress g_erase_tmpdir_and_scratchdir
  • Improve some log messages for USB support
  • Try to improve install in mindi to avoid issues with isolinux.cfg not installed vene if in the pkg :-(
  • Improve mindi-busybox build
  • In conformity with pb 0.8.9
  • Add support for Ubuntu 7.10 in build process
  • Add USB Key button to Menu UI (CD streamer removed)
  • Attempt to fix error messages on tmp/scratch files at the end by removing those dir at the latest possible.
  • Fix a bug linked to the size of the -E param which could be used (Arnaud Tiger/René? Ribaud).
  • Integrate ~/.pbrc content into mondorescue.pb (required project-builder >= 0.8.7)
  • Put mondorescue in conformity with new pb filtering rules
  • Add USB support at restore time (no test done yet). New start-usb script PB varibale added where useful
  • Unmounting USB device before removal of temporary scratchdir
  • Stil refining USB copy back to mondo (one command was not executed)
  • No need to have the image subdor in the csratchdir when USB.
  • umount the USB partition before attempting to use it
  • Remove useless copy from mindi to mondo at end of USB handling

(risky merge, we are raising the limits of 2 diverging branches. The status of stable is not completely sure as such. Will need lots of tests, but it's not yet done :-()
(merge -r1692:1769 $SVN_M/branches/2.2.5)

File size: 4.8 KB
Line 
1How to Add a New Applet to BusyBox
2==================================
3
4This document details the steps you must take to add a new applet to BusyBox.
5
6Credits:
7Matt Kraai - initial writeup
8Mark Whitley - the remix
9Thomas Lundquist - Trying to keep it updated.
10
11When doing this you should consider using the latest svn trunk.
12This is a good thing if you plan to getting it commited into mainline.
13
14Initial Write
15-------------
16
17First, write your applet.  Be sure to include copyright information at the top,
18such as who you stole the code from and so forth. Also include the mini-GPL
19boilerplate. Be sure to name the main function <applet>_main instead of main.
20And be sure to put it in <applet>.c. Usage does not have to be taken care of by
21your applet.
22Make sure to #include "libbb.h" as the first include file in your applet so
23the bb_config.h and appropriate platform specific files are included properly.
24
25For a new applet mu, here is the code that would go in mu.c:
26
27(busybox.h already includes most usual header files. You do not need
28#include <stdio.h> etc...)
29
30
31----begin example code------
32
33/* vi: set sw=4 ts=4: */
34/*
35 * Mini mu implementation for busybox
36 *
37 * Copyright (C) [YEAR] by [YOUR NAME] <YOUR EMAIL>
38 *
39 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
40 */
41
42#include "libbb.h"
43#include "other.h"
44
45int mu_main(int argc, char **argv);
46int mu_main(int argc, char **argv)
47{
48    int fd;
49    char mu;
50
51    fd = xopen("/dev/random", O_RDONLY);
52
53    if ((n = safe_read(fd, &mu, 1)) < 1)
54        bb_perror_msg_and_die("/dev/random");
55
56    return mu;
57}
58
59----end example code------
60
61
62Coding Style
63------------
64
65Before you submit your applet for inclusion in BusyBox, (or better yet, before
66you _write_ your applet) please read through the style guide in the docs
67directory and make your program compliant.
68
69
70Some Words on libbb
71-------------------
72
73As you are writing your applet, please be aware of the body of pre-existing
74useful functions in libbb. Use these instead of reinventing the wheel.
75
76Additionally, if you have any useful, general-purpose functions in your
77applet that could be useful in other applets, consider putting them in libbb.
78
79And it may be possible that some of the other applets uses functions you
80could use. If so, you have to rip the function out of the applet and make
81a libbb function out of it.
82
83Adding a libbb function:
84------------------------
85
86Make a new file named <function_name>.c
87
88----start example code------
89
90#include "libbb.h"
91#include "other.h"
92
93int function(char *a)
94{
95    return *a;
96}
97
98----end example code------
99
100Add <function_name>.o in the right alphabetically sorted place
101in libbb/Kbuild. You should look at the conditional part of
102libbb/Kbuild aswell.
103
104You should also try to find a suitable place in include/libbb.h for
105the function declaration. If not, add it somewhere anyway, with or without
106ifdefs to include or not.
107
108You can look at libbb/Config.in and try to find out if the function is
109tuneable and add it there if it is.
110
111
112Placement / Directory
113---------------------
114
115Find the appropriate directory for your new applet.
116
117Make sure you find the appropriate places in the files, the applets are
118sorted alphabetically.
119
120Add the applet to Kbuild in the chosen directory:
121
122lib-$(CONFIG_MU)               += mu.o
123
124Add the applet to Config.in in the chosen directory:
125
126config CONFIG_MU
127    bool "MU"
128    default n
129    help
130      Returns an indeterminate value.
131
132
133Usage String(s)
134---------------
135
136Next, add usage information for you applet to include/usage.h.
137This should look like the following:
138
139    #define mu_trivial_usage \
140        "-[abcde] FILES"
141    #define mu_full_usage \
142        "Returns an indeterminate value.\n\n" \
143        "Options:\n" \
144        "\t-a\t\tfirst function\n" \
145        "\t-b\t\tsecond function\n" \
146        ...
147
148If your program supports flags, the flags should be mentioned on the first
149line (-[abcde]) and a detailed description of each flag should go in the
150mu_full_usage section, one flag per line. (Numerous examples of this
151currently exist in usage.h.)
152
153
154Header Files
155------------
156
157Next, add an entry to include/applets.h.  Be *sure* to keep the list
158in alphabetical order, or else it will break the binary-search lookup
159algorithm in busybox.c and the Gods of BusyBox smite you. Yea, verily:
160
161Be sure to read the top of applets.h before adding your applet.
162
163    /* all programs above here are alphabetically "less than" 'mu' */
164    USE_MU(APPLET(mu, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
165    /* all programs below here are alphabetically "greater than" 'mu' */
166
167
168The Grand Announcement
169----------------------
170
171Then create a diff by adding the new files with svn (remember your libbb files)
172    svn add <where you put it>/mu.c
173eventually also:
174    svn add libbb/function.c
175then
176    svn diff
177and send it to the mailing list:
178    busybox@busybox.net
179    http://busybox.net/mailman/listinfo/busybox
180
181Sending patches as attachments is preferred, but not required.
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