arch/x86/boot/string.c

   1 /* -*- linux-c -*- ------------------------------------------------------- *
   2  *
   3  *   Copyright (C) 1991, 1992 Linus Torvalds
   4  *   Copyright 2007 rPath, Inc. - All Rights Reserved
   5  *
   6  *   This file is part of the Linux kernel, and is made available under
   7  *   the terms of the GNU General Public License version 2.
   8  *
   9  * ----------------------------------------------------------------------- */
  10
  11 /*
  12  * Very basic string functions
  13  */
  14
  15 #include "boot.h"
  16
  17 int strcmp(const char *str1, const char *str2)
  18 {
  19         const unsigned char *s1 = (const unsigned char *)str1;
  20         const unsigned char *s2 = (const unsigned char *)str2;
  21         int delta = 0;
  22
  23         while (*s1 || *s2) {
  24                 delta = *s2 - *s1;
  25                 if (delta)
  26                         return delta;
  27                 s1++;
  28                 s2++;
  29         }
  30         return 0;
  31 }
  32
  33 size_t strnlen(const char *s, size_t maxlen)
  34 {
  35         const char *es = s;
  36         while (*es && maxlen) {
  37                 es++;
  38                 maxlen--;
  39         }
  40
  41         return (es - s);
  42 }
  43
  44 unsigned int atou(const char *s)
  45 {
  46         unsigned int i = 0;
  47         while (isdigit(*s))
  48                 i = i * 10 + (*s++ - '0');
  49         return i;
  50 }