Stefan Reinauer (stefan.reinauer@coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1726
-gerrit
commit e6c3a9fa6fa90679c6003f77883a67fdbd8a1c85 Author: Gabe Black gabeblack@google.com Date: Thu Sep 27 17:42:23 2012 -0700
libpayload: Add faster, architecture specific versions of memset and memcpy.
Change-Id: I0f3a82de860fd3afa10a557b37fb90fe6b06ae90 Signed-off-by: Gabe Black gabeblack@google.com --- payloads/libpayload/arch/i386/Makefile.inc | 1 + payloads/libpayload/arch/i386/string.c | 103 +++++++++++++++++++++++++++++ 2 files changed, 104 insertions(+)
diff --git a/payloads/libpayload/arch/i386/Makefile.inc b/payloads/libpayload/arch/i386/Makefile.inc index 2be5e54..8f68b07 100644 --- a/payloads/libpayload/arch/i386/Makefile.inc +++ b/payloads/libpayload/arch/i386/Makefile.inc @@ -31,6 +31,7 @@ head.o-y += head.S libc-y += main.c sysinfo.c libc-y += timer.c coreboot.c util.S libc-y += exec.S virtual.c +libc-y += string.c
# Multiboot support is configurable libc-$(CONFIG_MULTIBOOT) += multiboot.c diff --git a/payloads/libpayload/arch/i386/string.c b/payloads/libpayload/arch/i386/string.c new file mode 100644 index 0000000..19047ee --- /dev/null +++ b/payloads/libpayload/arch/i386/string.c @@ -0,0 +1,103 @@ +/* + * Copyright (C) 1991,1992,1993,1997,1998,2003, 2005 Free Software Foundation, Inc. + * This file is part of the GNU C Library. + * Copyright (c) 2011 The Chromium OS Authors. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* From glibc-2.14, sysdeps/i386/memset.c */ + +#include <stdint.h> + +#include "string.h" + +typedef uint32_t op_t; + +void *memset(void *dstpp, int c, size_t len) +{ + int d0; + unsigned long int dstp = (unsigned long int) dstpp; + + /* This explicit register allocation improves code very much indeed. */ + register op_t x asm("ax"); + + x = (unsigned char) c; + + /* Clear the direction flag, so filling will move forward. */ + asm volatile("cld"); + + /* This threshold value is optimal. */ + if (len >= 12) { + /* Fill X with four copies of the char we want to fill with. */ + x |= (x << 8); + x |= (x << 16); + + /* Adjust LEN for the bytes handled in the first loop. */ + len -= (-dstp) % sizeof(op_t); + + /* + * There are at least some bytes to set. No need to test for + * LEN == 0 in this alignment loop. + */ + + /* Fill bytes until DSTP is aligned on a longword boundary. */ + asm volatile( + "rep\n" + "stosb" /* %0, %2, %3 */ : + "=D" (dstp), "=c" (d0) : + "0" (dstp), "1" ((-dstp) % sizeof(op_t)), "a" (x) : + "memory"); + + /* Fill longwords. */ + asm volatile( + "rep\n" + "stosl" /* %0, %2, %3 */ : + "=D" (dstp), "=c" (d0) : + "0" (dstp), "1" (len / sizeof(op_t)), "a" (x) : + "memory"); + len %= sizeof(op_t); + } + + /* Write the last few bytes. */ + asm volatile( + "rep\n" + "stosb" /* %0, %2, %3 */ : + "=D" (dstp), "=c" (d0) : + "0" (dstp), "1" (len), "a" (x) : + "memory"); + + return dstpp; +} + +void *memcpy(void *dest, const void *src, size_t n) +{ + unsigned long d0, d1, d2; + + asm volatile( + "rep ; movsl\n\t" + "movl %4,%%ecx\n\t" + "rep ; movsb\n\t" + : "=&c" (d0), "=&D" (d1), "=&S" (d2) + : "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src) + : "memory" + ); + + return dest; +}