diff options
| -rw-r--r-- | arch/x86/include/asm/string.h | 2 | ||||
| -rw-r--r-- | arch/x86/lib/Makefile | 1 | ||||
| -rw-r--r-- | arch/x86/lib/string.c | 87 |
3 files changed, 89 insertions, 1 deletions
diff --git a/arch/x86/include/asm/string.h b/arch/x86/include/asm/string.h index 3643a79fdf..3aa6c1131b 100644 --- a/arch/x86/include/asm/string.h +++ b/arch/x86/include/asm/string.h @@ -23,7 +23,7 @@ extern void * memmove(void *, const void *, __kernel_size_t); #undef __HAVE_ARCH_MEMCHR extern void * memchr(const void *, int, __kernel_size_t); -#undef __HAVE_ARCH_MEMSET +#define __HAVE_ARCH_MEMSET extern void * memset(void *, int, __kernel_size_t); #undef __HAVE_ARCH_MEMZERO diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index eb5fa10398..90f328333c 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -38,6 +38,7 @@ COBJS-$(CONFIG_SYS_GENERIC_TIMER) += pcat_timer.o COBJS-$(CONFIG_PCI) += pci.o COBJS-$(CONFIG_PCI) += pci_type1.o COBJS-$(CONFIG_SYS_X86_REALMODE) += realmode.o +COBJS-y += string.o COBJS-$(CONFIG_SYS_X86_ISR_TIMER) += timer.o COBJS-$(CONFIG_VIDEO) += video_bios.o COBJS-$(CONFIG_VIDEO) += video.o diff --git a/arch/x86/lib/string.c b/arch/x86/lib/string.c new file mode 100644 index 0000000000..f2ea7e4e33 --- /dev/null +++ b/arch/x86/lib/string.c @@ -0,0 +1,87 @@ +/* + * 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 <compiler.h> +#include <asm/string.h> +#include <linux/types.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; +} |
