ubuntu-linux-kernel/arch/arm/boot/deflate_xip_data.sh

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2024-04-01 15:06:58 +00:00
#!/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"