busybox/INSTALL
Bernhard Reutner-Fischer d591a360d3 - merge -r15463:15564 from busybox_scratch branch through these changesets:
------------------------------------------------------------------------
r15465 | aldot | 2006-06-21 20:48:06 +0200 (Wed, 21 Jun 2006) | 3 lines

- use CONFIG_BUSYBOX_EXEC_PATH as before it one was broken by a recent revert.
- use xchdir() since all is invain if it fails there anyways, supposedly

------------------------------------------------------------------------
r15466 | aldot | 2006-06-21 20:55:16 +0200 (Wed, 21 Jun 2006) | 2 lines

- adjust docs to take CONFIG_BUSYBOX_EXEC_PATH into account.

------------------------------------------------------------------------
r15467 | aldot | 2006-06-21 21:31:24 +0200 (Wed, 21 Jun 2006) | 18 lines

- partial fallout of my TREE_USED touchup against gcc-4.2: rip unused vars, save
s 144 bytes
   text    data     bss     dec     hex filename
 862434   10156  645924 1518514  172bb2 busybox.old
 862322   10156  645892 1518370  172b22 busybox
function                                             old     new   delta
z_len                                                  4       -      -4
textend                                                4       -      -4
part_nb                                                4       -      -4
insize                                                 4       -      -4
ifile_size                                             4       -      -4
do_link                                                4       -      -4
new_text                                              70      60     -10
ipaddr_list_link                                      33      23     -10
gzip_main                                            898     822     -76
------------------------------------------------------------------------------
(add/remove: 0/6 grow/shrink: 0/3 up/down: 0/-120)           Total: -120 bytes


------------------------------------------------------------------------
r15468 | aldot | 2006-06-21 21:43:05 +0200 (Wed, 21 Jun 2006) | 19 lines

- remove useless global exports
function                                             old     new   delta
rpm_main                                             940    1601    +661
rpm_getstring                                        107     112      +5
rpm_getint                                           148     153      +5
loop_through_files                                   103     106      +3
fileaction_dobackup                                  115     113      -2
fileaction_list                                        5       -      -5
rpm_getcount                                          42       -     -42
extract_cpio_gz                                      161       -    -161
rpm_gettags                                          504       -    -504
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 4/1 up/down: 674/-714)          Total: -40 bytes

   text    data     bss     dec     hex filename
 862322   10156  645892 1518370  172b22 busybox.old
 862290   10156  645892 1518338  172b02 busybox


------------------------------------------------------------------------
r15555 | aldot | 2006-06-30 14:10:11 +0200 (Fri, 30 Jun 2006) | 22 lines

- shrink syslog a little bit, move a big buffer (for 'line') off the bss, fold s
emaphore stuff into single caller manually.
  stats:
function                                             old     new   delta
logMessage                                           395     427     +32
message                                             1245    1257     +12
opts                                                   -       4      +4
small                                                  1       -      -1
local_logging                                          4       -      -4
doRemoteLog                                            4       -      -4
circular_logging                                       4       -      -4
syslogd_main                                        1299    1285     -14
static.res                                            36      16     -20
.rodata                                           186650  186586     -64
static.line                                         1025       -   -1025
------------------------------------------------------------------------------
(add/remove: 1/5 grow/shrink: 2/3 up/down: 48/-1136)        Total: -1088 bytes
cow@s37:~/src/busybox_scratch$ size sysklogd/syslogd.o{.orig,}
   text    data     bss     dec     hex filename
   3723     348    5242    9313    2461 sysklogd/syslogd.o.orig
   3697     348    4188    8233    2029 sysklogd/syslogd.o

==============================================================================
Overall bloatcheck for the changeset mentioned above:
function                                             old     new   delta
rpm_main                                             953    1608    +655
logMessage                                           395     427     +32
message                                             1245    1257     +12
opts                                                   -       4      +4
rpm_getstring                                        107     110      +3
rpm_getint                                           148     151      +3
loop_through_files                                   103     104      +1
small                                                  1       -      -1
fileaction_dobackup                                  115     113      -2
z_len                                                  4       -      -4
textend                                                4       -      -4
part_nb                                                4       -      -4
local_logging                                          4       -      -4
insize                                                 4       -      -4
ifile_size                                             4       -      -4
do_link                                                4       -      -4
doRemoteLog                                            4       -      -4
circular_logging                                       4       -      -4
fileaction_list                                        5       -      -5
new_text                                              70      60     -10
ipaddr_list_link                                      33      23     -10
clear_bufs                                            31      21     -10
syslogd_main                                        1287    1273     -14
builtin_help                                         190     176     -14
static.res                                            36      16     -20
builtin_source                                       229     199     -30
rpm_getcount                                          42       -     -42
gzip_main                                            842     786     -56
.rodata                                           227176  227112     -64
lash_main                                            609     527     -82
busy_loop                                           3883    3739    -144
extract_cpio_gz                                      155       -    -155
rpm_gettags                                          501       -    -501
static.line                                         1025       -   -1025
------------------------------------------------------------------------------
(add/remove: 1/15 grow/shrink: 6/12 up/down: 710/-2221)     Total: -1511 bytes
2006-08-20 17:35:13 +00:00

126 lines
5.2 KiB
Plaintext

Building:
=========
The BusyBox build process is similar to the Linux kernel build:
make menuconfig # This creates a file called ".config"
make # This creates the "busybox" executable
make install # or make PREFIX=/path/from/root install
The full list of configuration and install options is available by typing:
make help
Quick Start:
============
The easy way to try out BusyBox for the first time, without having to install
it, is to enable all features and then use "standalone shell" mode with a
blank command $PATH.
To enable all features, use "make defconfig", which produces the largest
general-purpose configuration. (It's allyesconfig minus debugging options,
optional packaging choices, and a few special-purpose features requiring
extra configuration to use.)
make defconfig
make
PATH= ./busybox ash
Standalone shell mode causes busybox's built-in command shell to run
any built-in busybox applets directly, without looking for external
programs by that name. Supplying an empty command path (as above) means
the only commands busybox can find are the built-in ones.
Note that the standalone shell requires CONFIG_BUSYBOX_EXEC_PATH
to be set appropriately, depending on whether or not /proc/self/exe is
available or not. If you do not have /proc, then point that config option
to the location of your busybox binary, usually /bin/busybox.
Configuring Busybox:
====================
Busybox is optimized for size, but enabling the full set of functionality
still results in a fairly large executable -- more than 1 megabyte when
statically linked. To save space, busybox can be configured with only the
set of applets needed for each environment. The minimal configuration, with
all applets disabled, produces a 4k executable. (It's useless, but very small.)
The manual configurator "make menuconfig" modifies the existing configuration.
(For systems without ncurses, try "make config" instead.) The two most
interesting starting configurations are "make allnoconfig" (to start with
everything disabled and add just what you need), and "make defconfig" (to
start with everything enabled and remove what you don't need). If menuconfig
is run without an existing configuration, make defconfig will run first to
create a known starting point.
Other starting configurations (mostly used for testing purposes) include
"make allbareconfig" (enables all applets but disables all optional features),
"make allyesconfig" (enables absolutely everything including debug features),
and "make randconfig" (produce a random configuration).
Configuring BusyBox produces a file ".config", which can be saved for future
use. Run "make oldconfig" to bring a .config file from an older version of
busybox up to date.
Installing Busybox:
===================
Busybox is a single executable that can behave like many different commands,
and BusyBox uses the name it was invoked under to determine the desired
behavior. (Try "mv busybox ls" and then "./ls -l".)
Installing busybox consists of creating symlinks (or hardlinks) to the busybox
binary for each applet enabled in busybox, and making sure these symlinks are
in the shell's command $PATH. Running "make install" creates these symlinks,
or "make install-hardlinks" creates hardlinks instead (useful on systems with
a limited number of inodes). This install process uses the file
"busybox.links" (created by make), which contains the list of enabled applets
and the path at which to install them.
Installing links to busybox is not always necessary. The special applet name
"busybox" (or with any optional suffix, such as "busybox-static") uses the
first argument to determine which applet to behave as, for example
"./busybox cat LICENSE". (Running the busybox applet with no arguments gives
a list of all enabled applets.) The standalone shell can also call busybox
applets without links to busybox under other names in the filesystem. You can
also configure a standaone install capability into the busybox base applet,
and then install such links at runtime with one of "busybox --install" (for
hardlinks) or "busybox --install -s" (for symlinks).
If you enabled the busybox shared library feature (libbusybox.so) and want
to run tests without installing, set your LD_LIBRARY_PATH accordingly when
running the executable:
LD_LIBRARY_PATH=`pwd` ./busybox
Building out-of-tree:
=====================
By default, the BusyBox build puts its temporary files in the source tree.
Building from a read-only source tree, or building multiple configurations from
the same source directory, requires the ability to put the temporary files
somewhere else.
To build out of tree, cd to an empty directory and configure busybox from there:
make -f /path/to/source/Makefile defconfig
make
make install
Alternately, use the O=$BUILDPATH option (with an absolute path) during the
configuration step, as in:
make O=/some/empty/directory allyesconfig
cd /some/empty/directory
make
make PREFIX=. install
More Information:
=================
Se also the busybox FAQ, under the questions "How can I get started using
BusyBox" and "How do I build a BusyBox-based system?" The BusyBox FAQ is
available from http://www.busybox.net/FAQ.html or as the file
docs/busybox.net/FAQ.html in this tarball.