kernel/gen_kheaders.sh

   1 #!/bin/bash
   2 # SPDX-License-Identifier: GPL-2.0
   3
   4 # This script generates an archive consisting of kernel headers
   5 # for CONFIG_IKHEADERS.
   6 set -e
   7 sfile="$(readlink -f "$0")"
   8 outdir="$(pwd)"
   9 tarfile=$1
  10 cpio_dir=$outdir/$tarfile.tmp
  11
  12 dir_list="
  13 include/
  14 arch/$SRCARCH/include/
  15 "
  16
  17 # Support incremental builds by skipping archive generation
  18 # if timestamps of files being archived are not changed.
  19
  20 # This block is useful for debugging the incremental builds.
  21 # Uncomment it for debugging.
  22 # if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
  23 # else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
  24 # find $src_file_list -name "*.h" | xargs ls -l > /tmp/src-ls-$iter
  25 # find $obj_file_list -name "*.h" | xargs ls -l > /tmp/obj-ls-$iter
  26
  27 # include/generated/compile.h is ignored because it is touched even when none
  28 # of the source files changed. This causes pointless regeneration, so let us
  29 # ignore them for md5 calculation.
  30 pushd $srctree > /dev/null
  31 src_files_md5="$(find $dir_list -name "*.h"                        |
  32                 grep -v "include/generated/compile.h"              |
  33                 grep -v "include/generated/autoconf.h"             |
  34                 xargs ls -l | md5sum | cut -d ' ' -f1)"
  35 popd > /dev/null
  36 obj_files_md5="$(find $dir_list -name "*.h"                        |
  37                 grep -v "include/generated/compile.h"              |
  38                 grep -v "include/generated/autoconf.h"             |
  39                 xargs ls -l | md5sum | cut -d ' ' -f1)"
  40 # Any changes to this script will also cause a rebuild of the archive.
  41 this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
  42 if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
  43 if [ -f kernel/kheaders.md5 ] &&
  44         [ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
  45         [ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
  46         [ "$(cat kernel/kheaders.md5|head -3|tail -1)" == "$this_file_md5" ] &&
  47         [ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
  48                 exit
  49 fi
  50
  51 if [ "${quiet}" != "silent_" ]; then
  52        echo "  GEN     $tarfile"
  53 fi
  54
  55 rm -rf $cpio_dir
  56 mkdir $cpio_dir
  57
  58 pushd $srctree > /dev/null
  59 for f in $dir_list;
  60         do find "$f" -name "*.h";
  61 done | cpio --quiet -pd $cpio_dir
  62 popd > /dev/null
  63
  64 # The second CPIO can complain if files already exist which can
  65 # happen with out of tree builds. Just silence CPIO for now.
  66 for f in $dir_list;
  67         do find "$f" -name "*.h";
  68 done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
  69
  70 # Remove comments except SDPX lines
  71 find $cpio_dir -type f -print0 |
  72         xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
  73
  74 # Create archive and try to normalize metadata for reproducibility.
  75 # For compatibility with older versions of tar, files are fed to tar
  76 # pre-sorted, as --sort=name might not be available.
  77 find $cpio_dir -printf "./%P\n" | LC_ALL=C sort | \
  78     tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
  79     --owner=0 --group=0 --numeric-owner --no-recursion \
  80     -Jcf $tarfile -C $cpio_dir/ -T - > /dev/null
  81
  82 echo "$src_files_md5" >  kernel/kheaders.md5
  83 echo "$obj_files_md5" >> kernel/kheaders.md5
  84 echo "$this_file_md5" >> kernel/kheaders.md5
  85 echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
  86
  87 rm -rf $cpio_dir