Signed-off-by: Patrick Georgi patrick.georgi@secunet.com --- payloads/libpayload/include/strings.h | 35 ++++++++++++++++++++++++++++ payloads/libpayload/libc/Makefile.inc | 2 +- payloads/libpayload/libc/strings.c | 40 +++++++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+), 1 deletions(-) create mode 100644 payloads/libpayload/include/strings.h create mode 100644 payloads/libpayload/libc/strings.c
diff --git a/payloads/libpayload/include/strings.h b/payloads/libpayload/include/strings.h new file mode 100644 index 0000000..ce7fe93 --- /dev/null +++ b/payloads/libpayload/include/strings.h @@ -0,0 +1,35 @@ +/* + * This file is part of the libpayload project. + * + * Copyright (C) 2011 secunet Security Networks AG + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _STRING_H +#define _STRING_H + +int ffs(int i); + +#endif diff --git a/payloads/libpayload/libc/Makefile.inc b/payloads/libpayload/libc/Makefile.inc index 3cd98c9..d629ccc 100644 --- a/payloads/libpayload/libc/Makefile.inc +++ b/payloads/libpayload/libc/Makefile.inc @@ -32,7 +32,7 @@ TARGETS-$(CONFIG_LIBC) += libc/malloc.o libc/printf.o libc/console.o libc/string TARGETS-$(CONFIG_LIBC) += libc/memory.o libc/ctype.o libc/ipchecksum.o libc/lib.o TARGETS-$(CONFIG_LIBC) += libc/rand.o libc/time.o libc/exec.o TARGETS-$(CONFIG_LIBC) += libc/readline.o libc/getopt_long.o libc/sysinfo.o -TARGETS-$(CONFIG_LIBC) += libc/args.o +TARGETS-$(CONFIG_LIBC) += libc/args.o libc/strings.o
# should be moved to coreboot directory TARGETS-$(CONFIG_LAR) += libc/lar.o diff --git a/payloads/libpayload/libc/strings.c b/payloads/libpayload/libc/strings.c new file mode 100644 index 0000000..9a56ba1 --- /dev/null +++ b/payloads/libpayload/libc/strings.c @@ -0,0 +1,40 @@ +/* + * This file is part of the libpayload project. + * + * Copyright (C) 2011 secunet Security Networks AG + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +int ffs(int i) +{ + int count = 1; + if (i == 0) return 0; + + while ((i & 1) != 1) { + i>>=1; + count++; + } + return count; +}
* Patrick Georgi Patrick.Georgi@secunet.com [110225 13:11]:
Signed-off-by: Patrick Georgi patrick.georgi@secunet.com
payloads/libpayload/include/strings.h | 35 ++++++++++++++++++++++++++++ payloads/libpayload/libc/Makefile.inc | 2 +- payloads/libpayload/libc/strings.c | 40 +++++++++++++++++++++++++++++++++ 3 files changed, 76 insertions(+), 1 deletions(-) create mode 100644 payloads/libpayload/include/strings.h create mode 100644 payloads/libpayload/libc/strings.c
diff --git a/payloads/libpayload/include/strings.h b/payloads/libpayload/include/strings.h new file mode 100644 index 0000000..ce7fe93 --- /dev/null +++ b/payloads/libpayload/include/strings.h @@ -0,0 +1,35 @@ +#ifndef _STRING_H +#define _STRING_H
This should be _STRINGS_H otherwise it can/will conflict.
Otherwise
Acked-by: Stefan Reinauer stefan.reinauer@coreboot.org
Patrick Georgi wrote:
+int ffs(int i);
Wording in my ffs(3) page suggests that int can be 64 bit. We don't care?
//Peter
* Peter Stuge peter@stuge.se [110225 21:48]:
Patrick Georgi wrote:
+int ffs(int i);
Wording in my ffs(3) page suggests that int can be 64 bit. We don't care?
So far the only compiler I know where this could happen is MSVC. Since we have an endless amount of GNUisms in all of our code that basically limits us to gcc/llvm/sun compiler/intel compiler/... it will never be a problem for us.
We might want to consider a slightly bigger but non-looping and faster implementation
int ffs(int i) { int count = 1;
if (i == 0) return 0;
if (!(i & 0xffff)) { i >>= 16; count += 16; }
if (!(i & 0xff)) { i >>= 8; count += 8; }
if (!(i & 0xf)) { i >>= 4; count += 4; }
if (!(i & 3)) { i >>= 2; count += 2; }
if (!(i & 1)) { i >>= 1; count += 1; }
return count; }
Stefan
-
Patrick Georgi -
Peter Stuge -
Stefan Reinauer