1 files changed, 96 insertions, 0 deletions
diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
new file mode 100755
index 000000000..a72b154de
--- /dev/null
+++ b/scripts/mkcompile_h
@@ -0,0 +1,96 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+TARGET=$1
+ARCH=$2
+SMP=$3
+PREEMPT=$4
+PREEMPT_RT=$5
+CC_VERSION="$6"
+LD=$7
+
+vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
+
+# Do not expand names
+set -f
+
+# Fix the language to get consistent output
+LC_ALL=C
+export LC_ALL
+
+if [ -z "$KBUILD_BUILD_VERSION" ]; then
+	VERSION=$(cat .version 2>/dev/null || echo 1)
+else
+	VERSION=$KBUILD_BUILD_VERSION
+fi
+
+if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
+	TIMESTAMP=`date`
+else
+	TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
+fi
+if test -z "$KBUILD_BUILD_USER"; then
+	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
+else
+	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
+fi
+if test -z "$KBUILD_BUILD_HOST"; then
+	LINUX_COMPILE_HOST=`uname -n`
+else
+	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
+fi
+
+UTS_VERSION="#$VERSION"
+CONFIG_FLAGS=""
+if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
+if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
+if [ -n "$PREEMPT_RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"; fi
+
+# Truncate to maximum length
+UTS_LEN=64
+UTS_VERSION="$(echo $UTS_VERSION $CONFIG_FLAGS $TIMESTAMP | cut -b -$UTS_LEN)"
+
+# Generate a temporary compile.h
+
+{ echo /\* This file is auto generated, version $VERSION \*/
+  if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
+
+  echo \#define UTS_MACHINE \"$ARCH\"
+
+  echo \#define UTS_VERSION \"$UTS_VERSION\"
+
+  printf '#define LINUX_COMPILE_BY "%s"\n' "$LINUX_COMPILE_BY"
+  echo \#define LINUX_COMPILE_HOST \"$LINUX_COMPILE_HOST\"
+
+  LD_VERSION=$($LD -v | head -n1 | sed 's/(compatible with [^)]*)//' \
+		      | sed 's/[[:space:]]*$//')
+  printf '#define LINUX_COMPILER "%s"\n' "$CC_VERSION, $LD_VERSION"
+} > .tmpcompile
+
+# Only replace the real compile.h if the new one is different,
+# in order to preserve the timestamp and avoid unnecessary
+# recompilations.
+# We don't consider the file changed if only the date/time changed,
+# unless KBUILD_BUILD_TIMESTAMP was explicitly set (e.g. for
+# reproducible builds with that value referring to a commit timestamp).
+# A kernel config change will increase the generation number, thus
+# causing compile.h to be updated (including date/time) due to the
+# changed comment in the
+# first line.
+
+if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
+   IGNORE_PATTERN="UTS_VERSION"
+else
+   IGNORE_PATTERN="NOT_A_PATTERN_TO_BE_MATCHED"
+fi
+
+if [ -r $TARGET ] && \
+      grep -v $IGNORE_PATTERN $TARGET > .tmpver.1 && \
+      grep -v $IGNORE_PATTERN .tmpcompile > .tmpver.2 && \
+      cmp -s .tmpver.1 .tmpver.2; then
+   rm -f .tmpcompile
+else
+   vecho "  UPD     $TARGET"
+   mv -f .tmpcompile $TARGET
+fi
+rm -f .tmpver.1 .tmpver.2