1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0-only
3
4# XIP kernel .data segment compressor
5#
6# Created by:	Nicolas Pitre, August 2017
7# Copyright:	(C) 2017  Linaro Limited
8#
9
10# This script locates the start of the .data section in xipImage and
11# substitutes it with a compressed version. The needed offsets are obtained
12# from symbol addresses in vmlinux. It is expected that .data extends to
13# the end of xipImage.
14
15set -e
16
17VMLINUX="$1"
18XIPIMAGE="$2"
19
20DD="dd status=none"
21
22# Use "make V=1" to debug this script.
23case "$KBUILD_VERBOSE" in
24*1*)
25	set -x
26	;;
27esac
28
29sym_val() {
30	# extract hex value for symbol in $1
31	local val=$($NM "$VMLINUX" 2>/dev/null | sed -n "/ $1\$/{s/ .*$//p;q}")
32	[ "$val" ] || { echo "can't find $1 in $VMLINUX" 1>&2; exit 1; }
33	# convert from hex to decimal
34	echo $((0x$val))
35}
36
37__data_loc=$(sym_val __data_loc)
38_edata_loc=$(sym_val _edata_loc)
39base_offset=$(sym_val _xiprom)
40
41# convert to file based offsets
42data_start=$(($__data_loc - $base_offset))
43data_end=$(($_edata_loc - $base_offset))
44
45# Make sure data occupies the last part of the file.
46file_end=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" "$XIPIMAGE")
47if [ "$file_end" != "$data_end" ]; then
48	printf "end of xipImage doesn't match with _edata_loc (%#x vs %#x)\n" \
49	       $(($file_end + $base_offset)) $_edata_loc 1>&2
50	exit 1;
51fi
52
53# be ready to clean up
54trap 'rm -f "$XIPIMAGE.tmp"; exit 1' 1 2 3
55
56# substitute the data section by a compressed version
57$DD if="$XIPIMAGE" count=$data_start iflag=count_bytes of="$XIPIMAGE.tmp"
58$DD if="$XIPIMAGE"  skip=$data_start iflag=skip_bytes |
59gzip -9 >> "$XIPIMAGE.tmp"
60
61# replace kernel binary
62mv -f "$XIPIMAGE.tmp" "$XIPIMAGE"
63