1 files changed, 64 insertions, 0 deletions
diff --git a/arch/arm/boot/deflate_xip_data.sh b/arch/arm/boot/deflate_xip_data.sh
new file mode 100755
index 000000000000..1189598a25eb
--- /dev/null
+++ b/arch/arm/boot/deflate_xip_data.sh
@@ -0,0 +1,64 @@
+#!/bin/sh
+
+# XIP kernel .data segment compressor
+#
+# Created by:	Nicolas Pitre, August 2017
+# Copyright:	(C) 2017  Linaro Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+# This script locates the start of the .data section in xipImage and
+# substitutes it with a compressed version. The needed offsets are obtained
+# from symbol addresses in vmlinux. It is expected that .data extends to
+# the end of xipImage.
+
+set -e
+
+VMLINUX="$1"
+XIPIMAGE="$2"
+
+DD="dd status=none"
+
+# Use "make V=1" to debug this script.
+case "$KBUILD_VERBOSE" in
+*1*)
+	set -x
+	;;
+esac
+
+sym_val() {
+	# extract hex value for symbol in $1
+	local val=$($NM "$VMLINUX" | sed -n "/ $1$/{s/ .*$//p;q}")
+	[ "$val" ] || { echo "can't find $1 in $VMLINUX" 1>&2; exit 1; }
+	# convert from hex to decimal
+	echo $((0x$val))
+}
+
+__data_loc=$(sym_val __data_loc)
+_edata_loc=$(sym_val _edata_loc)
+base_offset=$(sym_val _xiprom)
+
+# convert to file based offsets
+data_start=$(($__data_loc - $base_offset))
+data_end=$(($_edata_loc - $base_offset))
+
+# Make sure data occupies the last part of the file.
+file_end=$(stat -c "%s" "$XIPIMAGE")
+if [ "$file_end" != "$data_end" ]; then
+	printf "end of xipImage doesn't match with _edata_loc (%#x vs %#x)\n" \
+	       $(($file_end + $base_offset)) $_edata_loc 2>&1
+	exit 1;
+fi
+
+# be ready to clean up
+trap 'rm -f "$XIPIMAGE.tmp"' 0 1 2 3
+
+# substitute the data section by a compressed version
+$DD if="$XIPIMAGE" count=$data_start iflag=count_bytes of="$XIPIMAGE.tmp"
+$DD if="$XIPIMAGE"  skip=$data_start iflag=skip_bytes |
+gzip -9 >> "$XIPIMAGE.tmp"
+
+# replace kernel binary
+mv -f "$XIPIMAGE.tmp" "$XIPIMAGE"