82 lines
1.9 KiB
Bash
Executable File
82 lines
1.9 KiB
Bash
Executable File
#!/bin/bash
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# SPDX-License-Identifier: GPL-2.0+
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#
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# Create an initrd directory if one does not already exist.
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#
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# Copyright (C) IBM Corporation, 2013
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#
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# Author: Connor Shu <Connor.Shu@ibm.com>
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D=tools/testing/selftests/rcutorture
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# Prerequisite checks
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[ -z "$D" ] && echo >&2 "No argument supplied" && exit 1
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if [ ! -d "$D" ]; then
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echo >&2 "$D does not exist: Malformed kernel source tree?"
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exit 1
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fi
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if [ -s "$D/initrd/init" ]; then
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echo "$D/initrd/init already exists, no need to create it"
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exit 0
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fi
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# Create a C-language initrd/init infinite-loop program and statically
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# link it. This results in a very small initrd.
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echo "Creating a statically linked C-language initrd"
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cd $D
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mkdir -p initrd
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cd initrd
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cat > init.c << '___EOF___'
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#ifndef NOLIBC
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#include <unistd.h>
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#include <sys/time.h>
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#endif
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volatile unsigned long delaycount;
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int main(int argc, int argv[])
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{
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int i;
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struct timeval tv;
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struct timeval tvb;
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for (;;) {
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sleep(1);
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/* Need some userspace time. */
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if (gettimeofday(&tvb, NULL))
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continue;
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do {
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for (i = 0; i < 1000 * 100; i++)
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delaycount = i * i;
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if (gettimeofday(&tv, NULL))
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break;
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tv.tv_sec -= tvb.tv_sec;
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if (tv.tv_sec > 1)
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break;
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tv.tv_usec += tv.tv_sec * 1000 * 1000;
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tv.tv_usec -= tvb.tv_usec;
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} while (tv.tv_usec < 1000);
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}
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return 0;
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}
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___EOF___
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# build using nolibc on supported archs (smaller executable) and fall
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# back to regular glibc on other ones.
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if echo -e "#if __x86_64__||__i386__||__i486__||__i586__||__i686__" \
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"||__ARM_EABI__||__aarch64__\nyes\n#endif" \
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| ${CROSS_COMPILE}gcc -E -nostdlib -xc - \
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| grep -q '^yes'; then
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# architecture supported by nolibc
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${CROSS_COMPILE}gcc -fno-asynchronous-unwind-tables -fno-ident \
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-nostdlib -include ../../../../include/nolibc/nolibc.h \
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-s -static -Os -o init init.c -lgcc
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else
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${CROSS_COMPILE}gcc -s -static -Os -o init init.c
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fi
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rm init.c
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echo "Done creating a statically linked C-language initrd"
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exit 0
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