strip kernel modules more aggressively: make all global symbols local, rename all symbols in the symbol table to make them compress better

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@30662 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 38 insertions, 0 deletions

diff --git a/scripts/strip-kmod.sh b/scripts/strip-kmod.sh
new file mode 100755
index 000000000..68da9e901
--- /dev/null
+++ b/scripts/strip-kmod.sh
@@ -0,0 +1,38 @@
+#!/usr/bin/env bash
+[ -n "$CROSS" ] || {
+	echo "The variable CROSS must be set to point to the cross-compiler prefix"
+	exit 1
+}
+
+MODULE="$1"
+
+[ "$#" -ne 1 ] && {
+	echo "Usage: $0 <module>"
+	exit 1
+}
+
+${CROSS}objcopy \
+	--strip-unneeded \
+	-R .comment \
+	-R .pdr \
+	-R .mdebug.abi32 \
+	-R .note.gnu.build-id \
+	-R .gnu.attributes \
+	-R .reginfo \
+	-G __this_module \
+	-x "$MODULE" "$MODULE.tmp"
+
+${CROSS}nm "$MODULE.tmp" | awk '
+BEGIN {
+	n = 0
+}
+
+$3 && $2 ~ /[brtd]/ && $3 !~ /\$LC/ {
+	print "--redefine-sym "$3"=_"n;
+	n = n + 1
+}
+' > "$MODULE.tmp1"
+
+${CROSS}objcopy `cat ${MODULE}.tmp1` ${MODULE}.tmp ${MODULE}.out
+mv "${MODULE}.out" "${MODULE}"
+rm -f "${MODULE}".t*