tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0+
3#
4# Create an initrd directory if one does not already exist.
5#
6# Copyright (C) IBM Corporation, 2013
7#
8# Author: Connor Shu <Connor.Shu@ibm.com>
9
10D=tools/testing/selftests/rcutorture
11
12# Prerequisite checks
13if [ ! -d "$D" ]; then
14 echo >&2 "$D does not exist: Malformed kernel source tree?"
15 exit 1
16fi
17if [ -s "$D/initrd/init" ]; then
18 echo "$D/initrd/init already exists, no need to create it"
19 exit 0
20fi
21
22# Create a C-language initrd/init infinite-loop program and statically
23# link it. This results in a very small initrd.
24echo "Creating a statically linked C-language initrd"
25cd $D
26mkdir -p initrd
27cd initrd
28cat > init.c << '___EOF___'
29#ifndef NOLIBC
30#include <unistd.h>
31#include <sys/time.h>
32#endif
33
34volatile unsigned long delaycount;
35
36int main(int argc, char *argv[])
37{
38 int i;
39 struct timeval tv;
40 struct timeval tvb;
41
42 printf("Torture-test rudimentary init program started, command line:\n");
43 for (i = 0; i < argc; i++)
44 printf(" %s", argv[i]);
45 printf("\n");
46 for (;;) {
47 sleep(1);
48 /* Need some userspace time. */
49 if (gettimeofday(&tvb, NULL))
50 continue;
51 do {
52 for (i = 0; i < 1000 * 100; i++)
53 delaycount = i * i;
54 if (gettimeofday(&tv, NULL))
55 break;
56 tv.tv_sec -= tvb.tv_sec;
57 if (tv.tv_sec > 1)
58 break;
59 tv.tv_usec += tv.tv_sec * 1000 * 1000;
60 tv.tv_usec -= tvb.tv_usec;
61 } while (tv.tv_usec < 1000);
62 }
63 return 0;
64}
65___EOF___
66
67# build using nolibc on supported archs (smaller executable) and fall
68# back to regular glibc on other ones.
69if echo -e "#if __x86_64__||__i386__||__i486__||__i586__||__i686__" \
70 "||__ARM_EABI__||__aarch64__||__s390x__||__loongarch__\nyes\n#endif" \
71 | ${CROSS_COMPILE}gcc -E -nostdlib -xc - \
72 | grep -q '^yes'; then
73 # architecture supported by nolibc
74 ${CROSS_COMPILE}gcc -fno-asynchronous-unwind-tables -fno-ident \
75 -nostdlib -include ../../../../include/nolibc/nolibc.h \
76 -s -static -Os -o init init.c -lgcc
77 ret=$?
78else
79 ${CROSS_COMPILE}gcc -s -static -Os -o init init.c
80 ret=$?
81fi
82
83if [ "$ret" -ne 0 ]
84then
85 echo "Failed to create a statically linked C-language initrd"
86 exit "$ret"
87fi
88
89rm init.c
90echo "Done creating a statically linked C-language initrd"
91
92exit 0