metalsvm/arch/x86/include/asm/string.h
Stefan Lankes 5ce3ed9338 First steps to support the system calls "fork" and "wait"
- Currently, the system call "fork" doesn't work and has a memory leak
- However, it is a good starting point for further developments.
2011-03-02 13:49:36 +01:00

87 lines
1.6 KiB
C

/*
* Written by the Chair for Operating Systems, RWTH Aachen University
*
* NO Copyright (C) 2010-2011, Stefan Lankes
* consider these trivial functions to be public domain.
*
* These functions are distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*/
#ifndef __ARCH_STRING_H__
#define __ARCH_STRING_H__
#include <metalsvm/stddef.h>
#include <asm/scc_memcpy.h>
#ifdef __cplusplus
extern "C" {
#endif
#ifdef HAVE_ARCH_MEMCPY
inline static void *memcpy(void *dest, const void *src, size_t count)
{
int32_t i, j, k;
if (BUILTIN_EXPECT(!dest || !src, 0))
return dest;
asm volatile (
"cld; rep ; movsl\n\t"
"movl %4, %%ecx\n\t"
"andl $3, %%ecx\n\t"
"rep ; movsb\n\t"
: "=&c"(i), "=&D"(j), "=&S"(k)
: "0"(count/4), "g"(count), "1"(dest), "2"(src) : "memory");
return dest;
}
#endif
#ifdef HAVE_ARCH_MEMSET
inline static void *memset(void *dest, int val, size_t count)
{
int32_t i, j;
if (BUILTIN_EXPECT(!dest, 0))
return dest;
asm volatile ("cld; rep ; stosb"
: "=&c"(i), "=&D"(j)
: "a"(val), "1"(dest), "0"(count) : "memory");
return dest;
}
#endif
#ifdef HAVE_ARCH_STRLEN
inline static size_t strlen(const char *str)
{
size_t len = 0;
uint32_t i, j;
if (BUILTIN_EXPECT(!str, 0))
return len;
asm volatile("not %%ecx; cld; repne ; scasb; not %%ecx; dec %%ecx"
: "=&c"(len), "=&D"(i), "=&a"(j)
: "2"(0), "1"(str), "0"(len)
: "memory");
return len;
}
#endif
#ifdef HAVE_ARCH_STRNCPY
char* strncpy(char *dest, const char *src, size_t n);
#endif
#ifdef HAVE_ARCH_STRCPY
char* strcpy(char *dest, const char *src);
#endif
#ifdef __cplusplus
}
#endif
#endif