Add native memset() function on x86

Change-Id: Ia118ebe0a4b59bdcefd78895141a365170f6aed2
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/737
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)
This commit is contained in:
Stefan Reinauer 2011-10-26 22:11:52 +00:00 committed by Stefan Reinauer
parent 0054afa11d
commit 1afe51af83
4 changed files with 95 additions and 0 deletions

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@ -76,6 +76,10 @@ config CMOS_DEFAULT_FILE
config BOOTBLOCK_SOUTHBRIDGE_INIT
string
config HAVE_ARCH_MEMSET
bool
default y
config HAVE_ARCH_MEMCPY
bool
default y

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@ -8,10 +8,12 @@ ramstage-$(CONFIG_MMCONF_SUPPORT) += pci_ops_mmconf.c
ramstage-y += pci_ops_auto.c
ramstage-y += exception.c
ramstage-$(CONFIG_IOAPIC) += ioapic.c
ramstage-y += memset.c
ramstage-y += memcpy.c
romstage-y += romstage_console.c
romstage-y += cbfs_and_run.c
romstage-y += memset.c
romstage-y += memcpy.c
smm-y += memcpy.c

85
src/arch/x86/lib/memset.c Normal file
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@ -0,0 +1,85 @@
/*
* Copyright (C) 1991,1992,1993,1997,1998,2003, 2005 Free Software Foundation, Inc.
* This file is part of the GNU C Library.
*
* 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 <string.h>
#include <stdint.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;
}

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@ -1,6 +1,8 @@
ifneq ($(CONFIG_HAVE_ARCH_MEMSET),y)
romstage-y += memset.c
endif
romstage-y += memchr.c
ifneq ($(CONFIG_HAVE_ARCH_MEMCPY),y)
romstage-y += memcpy.c
@ -19,7 +21,9 @@ romstage-$(CONFIG_CONSOLE_NE2K) += compute_ip_checksum.c
romstage-$(CONFIG_USBDEBUG) += usbdebug.c
romstage-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
ifneq ($(CONFIG_HAVE_ARCH_MEMSET),y)
ramstage-y += memset.c
endif
ramstage-y += memchr.c
ifneq ($(CONFIG_HAVE_ARCH_MEMCPY),y)
ramstage-y += memcpy.c