diff options
Diffstat (limited to 'tools/testing/selftests/rcutorture/bin/mkinitrd.sh')
| -rwxr-xr-x | tools/testing/selftests/rcutorture/bin/mkinitrd.sh | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh new file mode 100755 index 000000000000..da298394daa2 --- /dev/null +++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh @@ -0,0 +1,136 @@ +#!/bin/bash +# +# Create an initrd directory if one does not already exist. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, you can access it online at +# http://www.gnu.org/licenses/gpl-2.0.html. +# +# Copyright (C) IBM Corporation, 2013 +# +# Author: Connor Shu <Connor.Shu@ibm.com> + +D=tools/testing/selftests/rcutorture + +# Prerequisite checks +[ -z "$D" ] && echo >&2 "No argument supplied" && exit 1 +if [ ! -d "$D" ]; then + echo >&2 "$D does not exist: Malformed kernel source tree?" + exit 1 +fi +if [ -s "$D/initrd/init" ]; then + echo "$D/initrd/init already exists, no need to create it" + exit 0 +fi + +T=${TMPDIR-/tmp}/mkinitrd.sh.$$ +trap 'rm -rf $T' 0 2 +mkdir $T + +cat > $T/init << '__EOF___' +#!/bin/sh +# Run in userspace a few milliseconds every second. This helps to +# exercise the NO_HZ_FULL portions of RCU. +while : +do + q= + for i in \ + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \ + a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a + do + q="$q $i" + done + sleep 1 +done +__EOF___ + +# Try using dracut to create initrd +if command -v dracut >/dev/null 2>&1 +then + echo Creating $D/initrd using dracut. + # Filesystem creation + dracut --force --no-hostonly --no-hostonly-cmdline --module "base" $T/initramfs.img + cd $D + mkdir -p initrd + cd initrd + zcat $T/initramfs.img | cpio -id + cp $T/init init + chmod +x init + echo Done creating $D/initrd using dracut + exit 0 +fi + +# No dracut, so create a C-language initrd/init program and statically +# link it. This results in a very small initrd, but might be a bit less +# future-proof than dracut. +echo "Could not find dracut, attempting C initrd" +cd $D +mkdir -p initrd +cd initrd +cat > init.c << '___EOF___' +#ifndef NOLIBC +#include <unistd.h> +#include <sys/time.h> +#endif + +volatile unsigned long delaycount; + +int main(int argc, int argv[]) +{ + int i; + struct timeval tv; + struct timeval tvb; + + for (;;) { + sleep(1); + /* Need some userspace time. */ + if (gettimeofday(&tvb, NULL)) + continue; + do { + for (i = 0; i < 1000 * 100; i++) + delaycount = i * i; + if (gettimeofday(&tv, NULL)) + break; + tv.tv_sec -= tvb.tv_sec; + if (tv.tv_sec > 1) + break; + tv.tv_usec += tv.tv_sec * 1000 * 1000; + tv.tv_usec -= tvb.tv_usec; + } while (tv.tv_usec < 1000); + } + return 0; +} +___EOF___ + +# build using nolibc on supported archs (smaller executable) and fall +# back to regular glibc on other ones. +if echo -e "#if __x86_64__||__i386__||__i486__||__i586__||__i686__" \ + "||__ARM_EABI__||__aarch64__\nyes\n#endif" \ + | ${CROSS_COMPILE}gcc -E -nostdlib -xc - \ + | grep -q '^yes'; then + # architecture supported by nolibc + ${CROSS_COMPILE}gcc -fno-asynchronous-unwind-tables -fno-ident \ + -nostdlib -include ../bin/nolibc.h -lgcc -s -static -Os \ + -o init init.c +else + ${CROSS_COMPILE}gcc -s -static -Os -o init init.c +fi + +rm init.c +echo "Done creating a statically linked C-language initrd" + +exit 0 |