arch/arm/boot/deflate_xip_data.sh

   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=$data_start iflag=skip_bytes |
  59 gzip -9 >> "$XIPIMAGE.tmp"
  60
  61 # replace kernel binary
  62 mv -f "$XIPIMAGE.tmp" "$XIPIMAGE"