arch/arm/boot/deflate_xip_data.sh

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