emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make busybox an optional applet

Browse Source 
If it's disabled, code shrinks by about 900 bytes:

function                                             old     new   delta
usr_bin                                               10       -     -10
usr_sbin                                              11       -     -11
install_dir                                           20       -     -20
applet_install_loc                                   184       -    -184
run_applet_and_exit                                  686      21    -665
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-890)           Total: -890 bytes
   text    data     bss     dec     hex filename
 911327     493    7336  919156   e0674 busybox_old
 909848     493    7336  917677   e00ad busybox_unstripped

but busybox executable by itself does not say anything useful:

$ busybox
busybox: applet not found

Based on the patch by Ron Yorston <rmy@pobox.com>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-05-31 02:42:49 +02:00
parent 877dedb825
commit 8e95068c7f
2 changed files with 19 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
Config.in
View File

@ -116,9 +116,21 @@ config FEATURE_COMPRESS_USAGE
and have very little memory, this might not be a win. Otherwise,
you probably want this.
config BUSYBOX
bool "Include busybox applet"
default y
help
The busybox applet provides general help regarding busybox and
allows the included applets to be listed. It's also required
if applet links are to be installed at runtime.
If you can live without these features disabling this will save
some space.
config FEATURE_INSTALLER
bool "Support --install [-s] to install applet links at runtime"
default y
depends on BUSYBOX
help
Enable 'busybox --install [-s]' support. This will allow you to use
busybox at runtime to create hard links or symlinks for all the

10
libbb/appletlib.c
View File

@ -701,7 +701,7 @@ static void install_links(const char *busybox, int use_symbolic_links,
continue;
}
}
# else
# elif ENABLE_BUSYBOX
static void install_links(const char *busybox UNUSED_PARAM,
int use_symbolic_links UNUSED_PARAM,
char *custom_install_dir UNUSED_PARAM)
@ -709,6 +709,7 @@ static void install_links(const char *busybox UNUSED_PARAM,
}
# endif
# if ENABLE_BUSYBOX
/* If we were called as "busybox..." */
static int busybox_main(char **argv)
{
@ -784,10 +785,10 @@ static int busybox_main(char **argv)
const char *a = applet_names;
dup2(1, 2);
while (*a) {
# if ENABLE_FEATURE_INSTALLER
# if ENABLE_FEATURE_INSTALLER
if (argv[1][6]) /* --list-full? */
full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
# endif
# endif
full_write2_str(a);
full_write2_str("\n");
i++;
@ -843,6 +844,7 @@ static int busybox_main(char **argv)
/* POSIX: "If a command is not found, the exit status shall be 127" */
exit(127);
}
# endif
void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
{
@ -886,8 +888,10 @@ void FAST_FUNC run_applet_and_exit(const char *name, char **argv)
{
int applet;
# if ENABLE_BUSYBOX
if (is_prefixed_with(name, "busybox"))
exit(busybox_main(argv));
# endif
/* find_applet_by_name() search is more expensive, so goes second */
applet = find_applet_by_name(name);
if (applet >= 0)