xref: /openbmc/linux/scripts/mkcompile_h (revision 6c33a6f4) 
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="$CONFIG_FLAGS PREEMPT_RT"; fi
58
59# Truncate to maximum length
60UTS_LEN=64
61UTS_VERSION="$(echo $UTS_VERSION $CONFIG_FLAGS $TIMESTAMP | cut -b -$UTS_LEN)"
62
63# Generate a temporary compile.h
64
65{ echo /\* This file is auto generated, version $VERSION \*/
66  if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
67
68  echo \#define UTS_MACHINE \"$ARCH\"
69
70  echo \#define UTS_VERSION \"$UTS_VERSION\"
71
72  printf '#define LINUX_COMPILE_BY "%s"\n' "$LINUX_COMPILE_BY"
73  echo \#define LINUX_COMPILE_HOST \"$LINUX_COMPILE_HOST\"
74
75  echo \#define LINUX_COMPILER \"`$CC -v 2>&1 | grep ' version ' | sed 's/[[:space:]]*$//'`\"
76} > .tmpcompile
77
78# Only replace the real compile.h if the new one is different,
79# in order to preserve the timestamp and avoid unnecessary
80# recompilations.
81# We don't consider the file changed if only the date/time changed.
82# A kernel config change will increase the generation number, thus
83# causing compile.h to be updated (including date/time) due to the
84# changed comment in the
85# first line.
86
87if [ -r $TARGET ] && \
88      grep -v 'UTS_VERSION' $TARGET > .tmpver.1 && \
89      grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 && \
90      cmp -s .tmpver.1 .tmpver.2; then
91   rm -f .tmpcompile
92else
93   vecho "  UPD     $TARGET"
94   mv -f .tmpcompile $TARGET
95fi
96rm -f .tmpver.1 .tmpver.2
97