1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3
4TARGET=$1
5ARCH=$2
6SMP=$3
7PREEMPT=$4
8PREEMPT_RT=$5
9CC=$6
10
11vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
12
13# If compile.h exists already and we don't own autoconf.h
14# (i.e. we're not the same user who did make *config), don't
15# modify compile.h
16# So "sudo make install" won't change the "compiled by <user>"
17# do "compiled by root"
18
19if [ -r $TARGET -a ! -O include/generated/autoconf.h ]; then
20  vecho "  SKIPPED $TARGET"
21  exit 0
22fi
23
24# Do not expand names
25set -f
26
27# Fix the language to get consistent output
28LC_ALL=C
29export LC_ALL
30
31if [ -z "$KBUILD_BUILD_VERSION" ]; then
32	VERSION=$(cat .version 2>/dev/null || echo 1)
33else
34	VERSION=$KBUILD_BUILD_VERSION
35fi
36
37if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
38	TIMESTAMP=`date`
39else
40	TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
41fi
42if test -z "$KBUILD_BUILD_USER"; then
43	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
44else
45	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
46fi
47if test -z "$KBUILD_BUILD_HOST"; then
48	LINUX_COMPILE_HOST=`hostname`
49else
50	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
51fi
52
53UTS_VERSION="#$VERSION"
54CONFIG_FLAGS=""
55if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
56if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
57if [ -n "$PREEMPT_RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"; fi
58UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
59
60# Truncate to maximum length
61
62UTS_LEN=64
63UTS_TRUNCATE="cut -b -$UTS_LEN"
64
65# Generate a temporary compile.h
66
67{ echo /\* This file is auto generated, version $VERSION \*/
68  if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
69
70  echo \#define UTS_MACHINE \"$ARCH\"
71
72  echo \#define UTS_VERSION \"`echo $UTS_VERSION | $UTS_TRUNCATE`\"
73
74  echo \#define LINUX_COMPILE_BY \"`echo $LINUX_COMPILE_BY | $UTS_TRUNCATE`\"
75  echo \#define LINUX_COMPILE_HOST \"`echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE`\"
76
77  echo \#define LINUX_COMPILER \"`$CC -v 2>&1 | grep ' version ' | sed 's/[[:space:]]*$//'`\"
78} > .tmpcompile
79
80# Only replace the real compile.h if the new one is different,
81# in order to preserve the timestamp and avoid unnecessary
82# recompilations.
83# We don't consider the file changed if only the date/time changed.
84# A kernel config change will increase the generation number, thus
85# causing compile.h to be updated (including date/time) due to the
86# changed comment in the
87# first line.
88
89if [ -r $TARGET ] && \
90      grep -v 'UTS_VERSION' $TARGET > .tmpver.1 && \
91      grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 && \
92      cmp -s .tmpver.1 .tmpver.2; then
93   rm -f .tmpcompile
94else
95   vecho "  UPD     $TARGET"
96   mv -f .tmpcompile $TARGET
97fi
98rm -f .tmpver.1 .tmpver.2
99