genlib.c

完整的Bell实验室的嵌入式文件系统TFS

/* genlib.c:
 *  This file has some of the stuff that is typically pulled in by the c
 *  library.  It is provided as local source so that the monitor can be
 *  built without the need for a library.  Some of this code was taken from
 *  the Berkley source code (see notice below).
 *
 *  General notice:
 *  This code is part of a boot-monitor package developed as a generic base
 *  platform for embedded system designs.  As such, it is likely to be
 *  distributed to various projects beyond the control of the original
 *  author.  Please notify the author of any enhancements made or bugs found
 *  so that all may benefit from the changes.  In addition, notification back
 *  to the author will allow the new user to pick up changes that may have
 *  been made by other users after this version of the code was distributed.
 *
 *  Note1: the majority of this code was edited with 4-space tabs.
 *  Note2: as more and more contributions are accepted, the term "author"
 *         is becoming a mis-representation of credit.
 *
 *  Original author:    Ed Sutter
 *  Email:              [e-mail]
 *  Phone:              908-582-2351
 */
/*
 * Copyright (c) 1988, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the University of
 *  California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include "ctype.h"
#include "genlib.h"
#include "stddefs.h"

char *BSDCRN = "Copyright (c) 1988, 1993 The Regents of the University of California.  All rights reserved.";

/* If an application is using this source code, then the printf() calls
 * might want to be redirected to mon_printf...
 */
#ifdef MONPRINTF
extern int mon_printf();
#define printf mon_printf
#endif

int
abs(int arg)
{
    return (arg >= 0 ? arg : -arg);
}

int
atoi(char *p)
{
    int n, c, neg;

    neg = 0;
    if (!isdigit((c = *p))) {
        while (isspace(c))
            c = *++p;
        switch (c) {
        case '-':
            neg++;
            break;
        case '+': /* fall-through */
            c = *++p;
            break;
        }
        if (!isdigit(c))
            return (0);
    }
    for (n = '0' - c; isdigit((c = *++p)); ) {
        n *= 10;        /* two steps to avoid unnecessary overflow */
        n += '0' - c;   /* accum neg to avoid surprises at MAX */
    }
    return (neg ? n : -n);
}

unsigned char   ctypetbl[] = {
     0,     _C,     _C,     _C,     _C,     _C,     _C,     _C,
    _C,     _S|_C,  _S|_C,  _S|_C,  _S|_C,  _S|_C,  _C,     _C,
    _C,     _C,     _C,     _C,     _C,     _C,     _C,     _C,
    _C,     _C,     _C,     _C,     _C,     _C,     _C,     _C,
    _S|_B,  _P,     _P,     _P,     _P,     _P,     _P,     _P,
    _P,     _P,     _P,     _P,     _P,     _P,     _P,     _P,
    _N|_X,  _N|_X,  _N|_X,  _N|_X,  _N|_X,  _N|_X,  _N|_X,  _N|_X,
    _N|_X,  _N|_X,  _P,     _P,     _P,     _P,     _P,     _P,
    _P,     _U|_X,  _U|_X,  _U|_X,  _U|_X,  _U|_X,  _U|_X,  _U,
    _U,     _U,     _U,     _U,     _U,     _U,     _U,     _U,
    _U,     _U,     _U,     _U,     _U,     _U,     _U,     _U,
    _U,     _U,     _U,     _P,     _P,     _P,     _P,     _P,
    _P,     _L|_X,  _L|_X,  _L|_X,  _L|_X,  _L|_X,  _L|_X,  _L,
    _L,     _L,     _L,     _L,     _L,     _L,     _L,     _L,
    _L,     _L,     _L,     _L,     _L,     _L,     _L,     _L,
    _L,     _L,     _L,     _P,     _P,     _P,     _P,     _C,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0,
     0,      0,      0,      0,      0,      0,      0,      0
};

/* memccpy():
 * Copy s2 to s1, stopping if character c is copied. Copy no more than n bytes.
 * Return a pointer to the byte after character c in the copy,
 * or NULL if c is not found in the first n bytes.
 */
char *
memccpy(register char *s1,register char *s2,register int c,register int n)
{
    while (--n >= 0)
        if ((*s1++ = *s2++) == c)
            return (s1);
    return (0);
}

/* memchr():
 * Return the ptr in sp at which the character c appears;
 *   NULL if not found in n chars; don't stop at \0.
 */
char *
memchr(register char *sp, register char c,register int n)
{
    while (--n >= 0)
        if (*sp++ == c)
            return (--sp);
    return (0);
}

/* memcmp():
 * Compare n bytes:  s1>s2: >0  s1==s2: 0  s1<s2: <0
 */
int
memcmp(register char *s1,register char *s2,register int n)
{
    int diff;

    if (s1 != s2)
        while (--n >= 0)
            if ((diff = (*s1++ - *s2++)))
                return (diff);
    return (0);
}

/* memcpy():
 *  Copy n bytes from 'from' to 'to'; return 'to'.
 *  This version of memcpy() tries to take advantage of address alignment.
 *  The goal is to do as many of the copies on 4-byte aligned addresses,
 *  falling back to 2-byte alignment, and finally, if there is no other
 *  way, simple byte-by-byte copy.
 *  Note that there is some point where the amount of overhead may exceed
 *  the byte count; hence, this will take longer for small byte counts.
 *  The assumption here is that small byte count memcpy() calls don't really
 *  care.
 */
char *
memcpy(char *to,char *from,int count)
{
    char    *to_copy, *end;

    to_copy = to;

#if INCLUDE_QUICKMEMCPY
    /* If count is greater than 8, get fancy, else just do byte-copy... */
    if (count > 8) {
        /* Attempt to optimize the transfer here... */
        if (((int)to & 3) && ((int)from & 3)) {
            /* If from and to pointers are both unaligned to the
             * same degree then we can do a few char copies to get them
             * 4-byte aligned and then do a lot of 4-byte aligned copies.
             */
            if (((int)to & 3) == ((int)from & 3)) {
                while((int)to & 3) {
                    *to++ = *from++;
                    count--;
                }
            }
            /* If from and to pointers are both odd, but different, then
             * we can increment them both by 1 and do a bunch of 2-byte
             * aligned copies...
             */
            else if (((int)to & 1) && ((int)from & 1)) {
                *to++ = *from++;
                count--;
            }
        }
    
        /* If both pointers are now 4-byte aligned or 2-byte aligned,
         * take advantage of that here...
         */
        if (!((int)to & 3) && !((int)from & 3)) {
            end = to + (count & ~3);
            count = count & 3;
            while(to < end) {
                *(ulong *)to = *(ulong *)from;
                from += 4;
                to += 4;
            }
        }
        else if (!((int)to & 1) && !((int)from & 1)) {
            end = to + (count & ~1);
            count = count & 1;
            while(to < end) {
                *(ushort *)to = *(ushort *)from;
                from += 2;
                to += 2;
            }
        }
    }
#endif

    if (count) {
        end = to + count;
        while(to < end)
            *to++ = *from++;
    }
    return(to_copy);
}

void
bcopy(char *from, char *to, int size)
{
    memcpy(to,from,size);
}

/* memset():
 * Set an array of n chars starting at sp to the character c.
 * Return sp.
 */
char *
memset(register char *sp, register char c, register int n)
{
    register char *sp0 = sp;

    while (--n >= 0)
        *sp++ = c;
    return (sp0);
}

/* strcat():
 * Concatenate s2 on the end of s1.  S1's space must be large enough.
 * Return s1.
 */

char *
strcat(register char *s1, register char *s2)
{
    register char *os1;

    os1 = s1;
    while(*s1++)
        ;
    --s1;
    while((*s1++ = *s2++))
        ;
    return(os1);
}

/* strchr():
 * Return the ptr in sp at which the character c appears;
 * NULL if not found
 */
char *
strchr(register char *sp, register char c)
{
    do {
        if(*sp == c)
            return(sp);
    } while(*sp++);
    return((char *)0);
}

/* strstr():
 * Find the first occurrence of find in s.
 */
char *
strstr(register char *s, register char *find)
{
    register char c, sc;
    register int len;

    if ((c = *find++) != 0) {
        len = strlen(find);
        do {
            do {
                if ((sc = *s++) == 0)
                    return ((char *)0);
            } while (sc != c);
        } while (strncmp(s, find, len) != 0);
        s--;
    }
    return ((char *)s);
}

/* strcmp():
 * Compare strings:  s1>s2: >0  s1==s2: 0  s1<s2: <0
 */
int
strcmp(register char *s1,register char * s2)
{

    if(s1 == s2)
        return(0);
    while(*s1 == *s2++)
        if(*s1++ == '\0')
            return(0);
    return(*s1 - *--s2);
}

/* strcpy():
 * Copy string s2 to s1.  s1 must be large enough.
 * return s1
 */

char *
strcpy(register char *s1,register char *s2)
{
    register char *os1;

    os1 = s1;
    while((*s1++ = *s2++))
        ;
    return(os1);
}

/* strlen():
 * Returns the number of