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
15 set -e
16
17 VMLINUX="$1"
18 XIPIMAGE="$2"
19
20 DD="dd status=none"
21
22 # Use "make V=1" to debug this script.
23 case "$KBUILD_VERBOSE" in
24 *1*)
25 set -x
26 ;;
27 esac
28
29 sym_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)
39 base_offset=$(sym_val _xiprom)
40
41 # convert to file based offsets
42 data_start=$(($__data_loc - $base_offset))
43 data_end=$(($_edata_loc - $base_offset))
44
45 # Make sure data occupies the last part of the file.
46 file_end=$(${CONFIG_SHELL} "${srctree}/scripts/file-size.sh" "$XIPIMAGE")
47 if [ "$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)) $_edata_loc 1>&2
50 exit 1;
51 fi
52
53 # be ready to clean up
54 trap 'rm -f "$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 |
59 $KGZIP -9 >> "$XIPIMAGE.tmp"
60
61 # replace kernel binary
62 mv -f "$XIPIMAGE.tmp" "$XIPIMAGE"
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