13 # --sort-common reduces padding
14 # --sort-section alignment reduces padding
15 # --gc-sections throws out unused sections,
16 # does not work for shared libs
17 # -On Not used, maybe useful?
19 # List of files to link:
20 # $l_list == --start-group -llib1 -llib2 --end-group
21 # --start-group $O_FILES $A_FILES --end-group
23 # Shared library link:
24 # -shared self-explanatory
25 # -fPIC position-independent code
26 # --enable-new-dtags ?
28 # -soname="libbusybox.so.$BB_VER"
29 # --undefined=lbb_main Seed name to start pulling from
30 # (otherwise we'll need --whole-archive)
31 # -static Not used, but may be useful! manpage:
32 # "... This option can be used with -shared.
33 # Doing so means that a shared library
34 # is being created but that all of the library's
35 # external references must be resolved by pulling
36 # in entries from static libraries."
40 printf "%s\n" "Output of:" >$EXE.out
41 printf "%s\n" "$*" >>$EXE.out
42 printf "%s\n" "==========" >>$EXE.out
43 $debug && echo "Trying: $*"
56 # Sanitize lib list (dups, extra spaces etc)
57 LDLIBS=`echo "$LDLIBS" | xargs -n1 | sort | uniq | xargs`
59 # First link with all libs. If it fails, bail out
60 echo "Trying libraries: $LDLIBS"
61 # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
62 l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
63 test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
67 -Wl,--sort-section -Wl,alignment \
69 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
72 echo "Failed: $* $l_list"
77 # Now try to remove each lib and build without it.
78 # Stop when no lib can be removed.
79 while test "$LDLIBS"; do
80 $debug && echo "Trying libraries: $LDLIBS"
82 for one in $LDLIBS; do
83 without_one=`echo " $LDLIBS " | sed "s/ $one / /g" | xargs`
84 # "lib1 lib2 lib3" -> "-llib1 -llib2 -llib3"
85 l_list=`echo "$without_one" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
86 test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
87 $debug && echo "Trying -l options: '$l_list'"
91 -Wl,--sort-section -Wl,alignment \
93 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
96 echo "Library $one is not needed"
100 echo "Library $one is needed"
103 # All libs were needed, can't remove any
105 # If there is no space char, the list has just one lib.
106 # I'm not sure that in this case lib really is 100% needed.
107 # Let's try linking without it anyway... thus commented out.
108 #{ echo "$LDLIBS" | grep -q ' '; } || break
111 # Make the binary with final, minimal list of libs
112 echo "Final link with: $LDLIBS"
113 l_list=`echo "$LDLIBS" | sed -e 's/ / -l/g' -e 's/^/-l/' -e 's/^-l$//'`
114 test "x$l_list" != "x" && l_list="-Wl,--start-group $l_list -Wl,--end-group"
115 # --verbose gives us gobs of info to stdout (e.g. linker script used)
116 if ! test -f busybox_ldscript; then
120 -Wl,--sort-section -Wl,alignment \
122 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
125 -Wl,-Map -Wl,$EXE.map \
132 echo "Custom linker script 'busybox_ldscript' found, using it"
133 # Add SORT_BY_ALIGNMENT to linker script (found in $EXE.out):
134 # .rodata : { *(.rodata SORT_BY_ALIGNMENT(.rodata.*) .gnu.linkonce.r.*) }
135 # *(.data SORT_BY_ALIGNMENT(.data.*) .gnu.linkonce.d.*)
136 # *(.bss SORT_BY_ALIGNMENT(.bss.*) .gnu.linkonce.b.*)
137 # This will eliminate most of the padding (~3kb).
138 # Hmm, "ld --sort-section alignment" should do it too.
142 -Wl,--sort-section -Wl,alignment \
144 -Wl,-T -Wl,busybox_ldscript \
145 -Wl,--start-group $O_FILES $A_FILES -Wl,--end-group \
148 -Wl,-Map -Wl,$EXE.map \
158 sharedlib_dir="0_lib"
160 if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then
161 mkdir "$sharedlib_dir" 2>/dev/null
162 test -d "$sharedlib_dir" || {
163 echo "Cannot make directory $sharedlib_dir"
166 ln -s "libbusybox.so.$BB_VER" "$sharedlib_dir"/libbusybox.so 2>/dev/null
168 EXE="$sharedlib_dir/libbusybox.so.${BB_VER}_unstripped"
172 -Wl,--enable-new-dtags \
174 -Wl,-soname="libbusybox.so.$BB_VER" \
175 -Wl,--undefined=lbb_main \
177 -Wl,--sort-section -Wl,alignment \
178 -Wl,--start-group $A_FILES -Wl,--end-group \
181 -Wl,-Map -Wl,$EXE.map \
184 echo "Linking $EXE failed"
188 $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/libbusybox.so.$BB_VER"
189 chmod a+x "$sharedlib_dir/libbusybox.so.$BB_VER"
190 echo "libbusybox: $sharedlib_dir/libbusybox.so.$BB_VER"
193 if test "$CONFIG_FEATURE_SHARED_BUSYBOX" = y; then
194 EXE="$sharedlib_dir/busybox_unstripped"
198 -Wl,--sort-section -Wl,alignment \
200 -Wl,--start-group $O_FILES -Wl,--end-group \
201 -L"$sharedlib_dir" -lbusybox \
203 -Wl,-Map -Wl,$EXE.map \
206 echo "Linking $EXE failed"
210 $STRIP -s --remove-section=.note --remove-section=.comment $EXE -o "$sharedlib_dir/busybox"
211 echo "busybox linked against libbusybox: $sharedlib_dir/busybox"
214 if test "$CONFIG_FEATURE_INDIVIDUAL" = y; then
215 echo "Linking individual applets against libbusybox (see $sharedlib_dir/*)"
216 gcc -DNAME_MAIN_CNAME -E -include include/autoconf.h include/applets.h \
220 while read name main junk; do
223 void lbb_prepare(const char *applet, char **argv);
224 int $main(int argc, char **argv);
226 int main(int argc, char **argv)
228 lbb_prepare(\"$name\", argv);
229 return $main(argc, argv);
231 " >"$sharedlib_dir/applet.c"
233 EXE="$sharedlib_dir/$name"
234 try $CC $LDFLAGS "$sharedlib_dir/applet.c" \
237 -Wl,--sort-section -Wl,alignment \
239 -L"$sharedlib_dir" -lbusybox \
242 echo "Linking $EXE failed"
246 rm -- "$sharedlib_dir/applet.c" $EXE.out
247 $STRIP -s --remove-section=.note --remove-section=.comment $EXE
252 # libbusybox.so is needed only for -lbusybox at link time,
253 # it is not needed at runtime. Deleting to reduce confusion.
254 rm "$sharedlib_dir"/libbusybox.so 2>/dev/null
255 exit 0 # or else we may confuse make