generate_BUFSIZ.sh: yet another tweak
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/scripts/generate_BUFSIZ.sh b/scripts/generate_BUFSIZ.sh
index 750fedb..8442619 100755
--- a/scripts/generate_BUFSIZ.sh
+++ b/scripts/generate_BUFSIZ.sh
@@ -6,6 +6,7 @@
. ./.config || exit 1
debug=false
+#debug=true
postcompile=false
test x"$1" = x"--post" && { postcompile=true; shift; }
@@ -62,6 +63,11 @@
$exitcmd
}
+round_down_COMMON_BUFSIZE() {
+ COMMON_BUFSIZE=$(( ($1-32) & 0xfffffe0 ))
+ COMMON_BUFSIZE=$(( COMMON_BUFSIZE < 1024 ? 1024 : COMMON_BUFSIZE ))
+}
+
# User does not want any funky stuff?
test x"$CONFIG_FEATURE_USE_BSS_TAIL" = x"y" || generate_std_and_exit
@@ -102,22 +108,43 @@
# How much space between _end[] and next page?
PAGE_MASK=$((PAGE_SIZE-1))
- COMMON_BUFSIZE=$(( (-END) & PAGE_MASK ))
- echo "COMMON_BUFSIZE = $COMMON_BUFSIZE bytes"
+ TAIL_SIZE=$(( (-END) & PAGE_MASK ))
+ $debug && echo "TAIL_SIZE:$TAIL_SIZE bytes"
- if test x"$method" != x"malloc"; then
- if test $COMMON_BUFSIZE -lt 1024; then
+ if test x"$method" = x"1k" || test x"$method" = x"big"; then
+ if test $TAIL_SIZE -lt 1024; then
# _end[] has no enough space for bb_common_bufsiz1[]
+ echo "Warning! Space in _end[] is too small ($TAIL_SIZE bytes)!"
+ echo "Rerun make to build a binary which doesn't use it!"
rm -- "$common_bufsiz_h.1k.OK" 2>/dev/null
{ md5sum <.config | cut -d' ' -f1; stat -c "%Y" .config; } >"$common_bufsiz_h.1k.FAIL"
- echo "Warning! Space in _end[] is too small ($COMMON_BUFSIZE bytes)!"
- echo "Rerun make to build a binary which doesn't use it!"
- rm busybox_unstripped busybox
+ rm busybox_unstripped busybox 2>/dev/null
+# Note: here we can do either a "malloc" or "std" build.
+# "malloc" gives a bit bigger code:
+# text bss filename
+# 804355 5385 busybox.std
+# 804618 4361 busybox.malloc
+# but may have a smaller .bss (not guaranteed!). Use "pmap -x" to verify.
exitcmd="exit 1"
+ generate_malloc_and_exit
else
+ PREV_SIZE=1024
+ test x"$method" = x"big" && PREV_SIZE=`cat -- "$common_bufsiz_h.1k.OK"`
+ round_down_COMMON_BUFSIZE $PREV_SIZE
+ PREV_BUFSIZE=$COMMON_BUFSIZE
+
rm -- "$common_bufsiz_h.1k.FAIL" 2>/dev/null
- echo $COMMON_BUFSIZE >"$common_bufsiz_h.1k.OK"
- test $COMMON_BUFSIZE -gt $((1024+32)) && echo "Rerun make to use larger COMMON_BUFSIZE"
+ echo $TAIL_SIZE >"$common_bufsiz_h.1k.OK"
+ round_down_COMMON_BUFSIZE $TAIL_SIZE
+ # emit message only if COMMON_BUFSIZE is indeed larger
+ test $COMMON_BUFSIZE -gt $PREV_BUFSIZE \
+ && echo "Rerun make to use larger COMMON_BUFSIZE ($COMMON_BUFSIZE)"
+#TODO: test $PREV_BUFSIZE -lt $TAIL_SIZE && PANIC!!!
+#Code size with COMMON_BUFSIZE > 1024 may be bigger than code with COMMON_BUFSIZE = 1024!
+#(currently we just hope "-32 and round down to 32" saves us)
+
+ test $COMMON_BUFSIZE = 1024 && generate_1k_and_exit
+ generate_big_and_exit $COMMON_BUFSIZE "big"
fi
fi
fi
@@ -127,13 +154,12 @@
if test -f "$common_bufsiz_h.1k.OK"; then
# Previous build succeeded fitting 1k into _end[].
# Try bigger COMMON_BUFSIZE if possible.
- COMMON_BUFSIZE=`cat -- "$common_bufsiz_h.1k.OK"`
- # Round down a bit
- COMMON_BUFSIZE=$(( (COMMON_BUFSIZE-32) & 0xfffffe0 ))
- COMMON_BUFSIZE=$(( COMMON_BUFSIZE < 1024 ? 1024 : COMMON_BUFSIZE ))
+ TAIL_SIZE=`cat -- "$common_bufsiz_h.1k.OK"`
+ round_down_COMMON_BUFSIZE $TAIL_SIZE
test $COMMON_BUFSIZE = 1024 && generate_1k_and_exit
generate_big_and_exit $COMMON_BUFSIZE "big"
fi
+
if test -f "$common_bufsiz_h.1k.FAIL"; then
# Previous build FAILED to fit 1k into _end[].
# Was it with same .config?
@@ -142,6 +168,7 @@
# If yes, then build a "malloced" version
if test x"$oldcfg" = x"$curcfg"; then
echo "Will not try 1k build, it failed before. Touch .config to override"
+# Note: here we can do either a "malloc" or "std" build.
generate_malloc_and_exit
fi
# else: try 1k version
@@ -149,5 +176,6 @@
rm -- "$common_bufsiz_h.1k.FAIL"
generate_1k_and_exit
fi
+
# There was no 1k build yet. Try it.
generate_1k_and_exit