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)

diff --git a/src/arch/x86/Kconfig b/src/arch/x86/Kconfig
index 5ee7c4ac7755a573d539e776ea1d1097fbb99f78..4ca49cbaf482b31b1ae54868fce5815e50b73aae 100644 (file)
--- a/src/arch/x86/Kconfig
+++ b/src/arch/x86/Kconfig
@@ -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

diff --git a/src/arch/x86/lib/Makefile.inc b/src/arch/x86/lib/Makefile.inc
index f99e429eeff229e767024f16879e50d60689f87f..3f4dc955600a4e242f7ea7e5639584c875ce3852 100644 (file)
--- a/src/arch/x86/lib/Makefile.inc
+++ b/src/arch/x86/lib/Makefile.inc
@@ -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

diff --git a/src/arch/x86/lib/memset.c b/src/arch/x86/lib/memset.c
new file mode 100644 (file)
index 0000000..7c8129a
--- /dev/null
+++ b/src/arch/x86/lib/memset.c
@@ -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;
+}

diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index 61b6451d0b4cdc1c5cc54849b5900eb68c3e9819..8ce72b2a9d53b56317ad2ce32796808454200897 100644 (file)
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -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