tools/testing/selftests/rcutorture/bin/mkinitrd.sh

Source file repositories/reference/linux-study-clean/tools/testing/selftests/rcutorture/bin/mkinitrd.sh

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/rcutorture/bin/mkinitrd.sh
Extension
.sh
Size
2321 bytes
Lines
96
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

#!/bin/bash
# SPDX-License-Identifier: GPL-2.0+
#
# Create an initrd directory if one does not already exist.
#
# Copyright (C) IBM Corporation, 2013
#
# Author: Connor Shu <Connor.Shu@ibm.com>

D=tools/testing/selftests/rcutorture

# Prerequisite checks
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

# Create a C-language initrd/init infinite-loop program and statically
# link it.  This results in a very small initrd.
echo "Creating a statically linked C-language 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, char *argv[])
{
	int i;
	struct timeval tv;
	struct timeval tvb;

	printf("Torture-test rudimentary init program started, command line:\n");
	for (i = 0; i < argc; i++)
		printf(" %s", argv[i]);
	printf("\n");
	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__||(__mips__ && _ABIO32)" \

Annotation

Implementation Notes