kernel/gen_kheaders.sh

   1 #!/bin/sh
   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/${tarfile%/*}/.tmp_cpio_dir
  11
  12 dir_list="
  13 include/
  14 arch/$SRCARCH/include/
  15 "
  16
  17 if ! command -v cpio >/dev/null; then
  18         echo >&2 "***"
  19         echo >&2 "*** 'cpio' could not be found."
  20         echo >&2 "***"
  21         exit 1
  22 fi
  23
  24 # Support incremental builds by skipping archive generation
  25 # if timestamps of files being archived are not changed.
  26
  27 # This block is useful for debugging the incremental builds.
  28 # Uncomment it for debugging.
  29 # if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
  30 # else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
  31 # find $all_dirs -name "*.h" | xargs ls -l > /tmp/ls-$iter
  32
  33 all_dirs=
  34 if [ "$building_out_of_srctree" ]; then
  35         for d in $dir_list; do
  36                 all_dirs="$all_dirs $srctree/$d"
  37         done
  38 fi
  39 all_dirs="$all_dirs $dir_list"
  40
  41 # include/generated/utsversion.h is ignored because it is generated after this
  42 # script is executed. (utsversion.h is unneeded for kheaders)
  43 #
  44 # When Kconfig regenerates include/generated/autoconf.h, its timestamp is
  45 # updated, but the contents might be still the same. When any CONFIG option is
  46 # changed, Kconfig touches the corresponding timestamp file include/config/*.
  47 # Hence, the md5sum detects the configuration change anyway. We do not need to
  48 # check include/generated/autoconf.h explicitly.
  49 #
  50 # Ignore them for md5 calculation to avoid pointless regeneration.
  51 headers_md5="$(find $all_dirs -name "*.h"                       |
  52                 grep -v "include/generated/utsversion.h"        |
  53                 grep -v "include/generated/autoconf.h"  |
  54                 xargs ls -l | md5sum | cut -d ' ' -f1)"
  55
  56 # Any changes to this script will also cause a rebuild of the archive.
  57 this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
  58 if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
  59 if [ -f kernel/kheaders.md5 ] &&
  60         [ "$(head -n 1 kernel/kheaders.md5)" = "$headers_md5" ] &&
  61         [ "$(head -n 2 kernel/kheaders.md5 | tail -n 1)" = "$this_file_md5" ] &&
  62         [ "$(tail -n 1 kernel/kheaders.md5)" = "$tarfile_md5" ]; then
  63                 exit
  64 fi
  65
  66 echo "  GEN     $tarfile"
  67
  68 rm -rf $cpio_dir
  69 mkdir $cpio_dir
  70
  71 if [ "$building_out_of_srctree" ]; then
  72         (
  73                 cd $srctree
  74                 for f in $dir_list
  75                         do find "$f" -name "*.h";
  76                 done | cpio --quiet -pd $cpio_dir
  77         )
  78 fi
  79
  80 # The second CPIO can complain if files already exist which can happen with out
  81 # of tree builds having stale headers in srctree. Just silence CPIO for now.
  82 for f in $dir_list;
  83         do find "$f" -name "*.h";
  84 done | cpio --quiet -pdu $cpio_dir >/dev/null 2>&1
  85
  86 # Remove comments except SDPX lines
  87 find $cpio_dir -type f -print0 |
  88         xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
  89
  90 # Create archive and try to normalize metadata for reproducibility.
  91 tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
  92     --owner=0 --group=0 --sort=name --numeric-owner --mode=u=rw,go=r,a+X \
  93     -I $XZ -cf $tarfile -C $cpio_dir/ . > /dev/null
  94
  95 echo $headers_md5 > kernel/kheaders.md5
  96 echo "$this_file_md5" >> kernel/kheaders.md5
  97 echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
  98
  99 rm -rf $cpio_dir