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
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