From b94ec36896dafc0a12106b1536fe87f99e9a0c5d Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Sun, 9 Sep 2018 13:33:02 +0200 Subject: rcutorture: Make use of nolibc when available This reduces the size of the init executable from ~800 kB to ~800 bytes on x86_64. This is only implemented for x86_64, i386, arm and arm64. Others not tested. Signed-off-by: Willy Tarreau Signed-off-by: Paul E. McKenney --- tools/testing/selftests/rcutorture/bin/mkinitrd.sh | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'tools/testing/selftests/rcutorture') diff --git a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh index 56a56ea06983..da298394daa2 100755 --- a/tools/testing/selftests/rcutorture/bin/mkinitrd.sh +++ b/tools/testing/selftests/rcutorture/bin/mkinitrd.sh @@ -82,8 +82,10 @@ cd $D mkdir -p initrd cd initrd cat > init.c << '___EOF___' +#ifndef NOLIBC #include #include +#endif volatile unsigned long delaycount; @@ -113,7 +115,21 @@ int main(int argc, int argv[]) return 0; } ___EOF___ -${CROSS_COMPILE}gcc -s -static -Os -o init init.c + +# 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" -- cgit v1.2.3-59-g8ed1b