source: branches/3.2/mindi-busybox/INSTALL @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
File size: 6.0 KB
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1Building:
2=========
3
4The BusyBox build process is similar to the Linux kernel build:
5
6  make menuconfig     # This creates a file called ".config"
7  make                # This creates the "busybox" executable
8  make install        # or make CONFIG_PREFIX=/path/from/root install
9
10The full list of configuration and install options is available by typing:
11
12  make help
13
14Quick Start:
15============
16
17The easy way to try out BusyBox for the first time, without having to install
18it, is to enable all features and then use "standalone shell" mode with a
19blank command $PATH.
20
21To enable all features, use "make defconfig", which produces the largest
22general-purpose configuration.  It's allyesconfig minus debugging options,
23optional packaging choices, and a few special-purpose features requiring
24extra configuration to use.  Then enable "standalone shell" feature:
25
26  make defconfig
27  make menuconfig
28  # select Busybox Settings
29  #   then General Configuration
30  #     then exec prefers applets
31  #   exit back to top level menu
32  #   select Shells
33  #     then Standalone shell
34  #   exit back to top level menu
35  # exit and save new configuration
36  #   OR
37  # use these commands to modify .config directly:
38  sed -e 's/.*FEATURE_PREFER_APPLETS.*/CONFIG_FEATURE_PREFER_APPLETS=y/' -i .config
39  sed -e 's/.*FEATURE_SH_STANDALONE.*/CONFIG_FEATURE_SH_STANDALONE=y/' -i .config
40  make
41  PATH= ./busybox ash
42
43Standalone shell mode causes busybox's built-in command shell to run
44any built-in busybox applets directly, without looking for external
45programs by that name.  Supplying an empty command path (as above) means
46the only commands busybox can find are the built-in ones.
47
48Note that the standalone shell requires CONFIG_BUSYBOX_EXEC_PATH
49to be set appropriately, depending on whether or not /proc/self/exe is
50available. If you do not have /proc, then point that config option
51to the location of your busybox binary, usually /bin/busybox.
52Another solution is to patch the kernel (see
53examples/linux-*_proc_self_exe.patch) to make exec("/proc/self/exe")
54always work.
55
56Configuring Busybox:
57====================
58
59Busybox is optimized for size, but enabling the full set of functionality
60still results in a fairly large executable -- more than 1 megabyte when
61statically linked.  To save space, busybox can be configured with only the
62set of applets needed for each environment.  The minimal configuration, with
63all applets disabled, produces a 4k executable.  (It's useless, but very small.)
64
65The manual configurator "make menuconfig" modifies the existing configuration.
66(For systems without ncurses, try "make config" instead.) The two most
67interesting starting configurations are "make allnoconfig" (to start with
68everything disabled and add just what you need), and "make defconfig" (to
69start with everything enabled and remove what you don't need).  If menuconfig
70is run without an existing configuration, make defconfig will run first to
71create a known starting point.
72
73Other starting configurations (mostly used for testing purposes) include
74"make allbareconfig" (enables all applets but disables all optional features),
75"make allyesconfig" (enables absolutely everything including debug features),
76and "make randconfig" (produce a random configuration).  The configs/ directory
77contains a number of additional configuration files ending in _defconfig which
78are useful in specific cases.  "make help" will list them.
79
80Configuring BusyBox produces a file ".config", which can be saved for future
81use.  Run "make oldconfig" to bring a .config file from an older version of
82busybox up to date.
83
84Installing Busybox:
85===================
86
87Busybox is a single executable that can behave like many different commands,
88and BusyBox uses the name it was invoked under to determine the desired
89behavior.  (Try "mv busybox ls" and then "./ls -l".)
90
91Installing busybox consists of creating symlinks (or hardlinks) to the busybox
92binary for each applet enabled in busybox, and making sure these symlinks are
93in the shell's command $PATH.  Running "make install" creates these symlinks,
94or "make install-hardlinks" creates hardlinks instead (useful on systems with
95a limited number of inodes).  This install process uses the file
96"busybox.links" (created by make), which contains the list of enabled applets
97and the path at which to install them.
98
99Installing links to busybox is not always necessary.  The special applet name
100"busybox" (or with any optional suffix, such as "busybox-static") uses the
101first argument to determine which applet to behave as, for example
102"./busybox cat LICENSE".  (Running the busybox applet with no arguments gives
103a list of all enabled applets.) The standalone shell can also call busybox
104applets without links to busybox under other names in the filesystem.  You can
105also configure a standalone install capability into the busybox base applet,
106and then install such links at runtime with one of "busybox --install" (for
107hardlinks) or "busybox --install -s" (for symlinks).
108
109If you enabled the busybox shared library feature (libbusybox.so) and want
110to run tests without installing, set your LD_LIBRARY_PATH accordingly when
111running the executable:
112
113  LD_LIBRARY_PATH=`pwd` ./busybox
114
115Building out-of-tree:
116=====================
117
118By default, the BusyBox build puts its temporary files in the source tree.
119Building from a read-only source tree, or building multiple configurations from
120the same source directory, requires the ability to put the temporary files
121somewhere else.
122
123To build out of tree, cd to an empty directory and configure busybox from there:
124
125  make KBUILD_SRC=/path/to/source -f /path/to/source/Makefile defconfig
126  make
127  make install
128
129Alternately, use the O=$BUILDPATH option (with an absolute path) during the
130configuration step, as in:
131
132  make O=/some/empty/directory allyesconfig
133  cd /some/empty/directory
134  make
135  make CONFIG_PREFIX=. install
136
137More Information:
138=================
139
140Se also the busybox FAQ, under the questions "How can I get started using
141BusyBox" and "How do I build a BusyBox-based system?"  The BusyBox FAQ is
142available from http://www.busybox.net/FAQ.html
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