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/* Project:     OSLib
 * Description: The OS Construction Kit
 * Date:                1.6.2000
 * Idea by:             Luca Abeni & Gerardo Lamastra
 *
 * OSLib is an SO project aimed at developing a common, easy-to-use
 * low-level infrastructure for developing OS kernels and Embedded
 * Applications; it partially derives from the HARTIK project but it
 * currently is independently developed.
 *
 * OSLib is distributed under GPL License, and some of its code has
 * been derived from the Linux kernel source; also some important
 * ideas come from studying the DJGPP go32 extender.
 *
 * We acknowledge the Linux Community, Free Software Foundation,
 * D.J. Delorie and all the other developers who believe in the
 * freedom of software and ideas.
 *
 * For legalese, check out the included GPL license.
 */


/*      Memory manipulation functions...
        Some of them are derived from Linux     */


#ifndef __LL_I386_MEM_H__
#define __LL_I386_MEM_H__

#include <ll/i386/defs.h>
BEGIN_DEF

/* Various string manipulation functions */

/* Assembler low level routines         */
/* File: Mem.S                          */

#ifndef NULL
    #define NULL 0L
#endif

#include <ll/sys/types.h>
#include <ll/i386/hw-data.h>

/*
#ifndef __HW_DEP_H__
    #include "hw_dep.h"
#endif
*/


extern inline void * __memcpy(void * to, const void * from, size_t n)
{
int d0, d1, d2;
__asm__ __volatile__(
        "cld\n\t"
        "rep ; movsl\n\t"
        "testb $2,%b4\n\t"
        "je 1f\n\t"
        "movsw\n"
        "1:\ttestb $1,%b4\n\t"
        "je 2f\n\t"
        "movsb\n"
        "2:"
        : "=&c" (d0), "=&D" (d1), "=&S" (d2)
        :"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
        : "memory");
return (to);
}

/*
 * This looks horribly ugly, but the compiler can optimize it totally,
 * as the count is constant.
 */

extern inline void * __constant_memcpy(void * to, const void * from, size_t n)
{
        switch (n) {
                case 0:
                        return to;
                case 1:
                        *(unsigned char *)to = *(const unsigned char *)from;
                        return to;
                case 2:
                        *(unsigned short *)to = *(const unsigned short *)from;
                        return to;
                case 3:
                        *(unsigned short *)to = *(const unsigned short *)from;
                        *(2+(unsigned char *)to) = *(2+(const unsigned char *)from);
                        return to;
                case 4:
                        *(unsigned long *)to = *(const unsigned long *)from;
                        return to;
                case 6: /* for Ethernet addresses */
                        *(unsigned long *)to = *(const unsigned long *)from;
                        *(2+(unsigned short *)to) = *(2+(const unsigned short *)from);
                        return to;
                case 8:
                        *(unsigned long *)to = *(const unsigned long *)from;
                        *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
                        return to;
                case 12:
                        *(unsigned long *)to = *(const unsigned long *)from;
                        *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
                        *(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
                        return to;
                case 16:
                        *(unsigned long *)to = *(const unsigned long *)from;
                        *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
                        *(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
                        *(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
                        return to;
                case 20:
                        *(unsigned long *)to = *(const unsigned long *)from;
                        *(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
                        *(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
                        *(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
                        *(4+(unsigned long *)to) = *(4+(const unsigned long *)from);
                        return to;
        }
#define COMMON(x) \
__asm__ __volatile__( \
        "cld\n\t" \
        "rep ; movsl" \
        x \
        : "=&c" (d0), "=&D" (d1), "=&S" (d2) \
        : "0" (n/4),"1" ((long) to),"2" ((long) from) \
        : "memory");

{
        int d0, d1, d2;
        switch (n % 4) {
                case 0: COMMON(""); return to;
                case 1: COMMON("\n\tmovsb"); return to;
                case 2: COMMON("\n\tmovsw"); return to;
                default: COMMON("\n\tmovsw\n\tmovsb"); return to;
        }
}
 
#undef COMMON
}

#define __HAVE_ARCH_MEMCPY
#define memcpy(t, f, n) \
(__builtin_constant_p(n) ? \
 __constant_memcpy((t),(f),(n)) : \
 __memcpy((t),(f),(n)))


extern inline void *lmemcpy(LIN_ADDR t, LIN_ADDR f, size_t n)
{
        void *p1;
        void *p2;

        p1 = (void *)(t);
        p2 = (void *)(f);
        return memcpy(p1, p2, n);
}

#define __HAVE_ARCH_MEMMOVE
extern inline void * memmove(void * dest,const void * src, size_t n)
{
int d0, d1, d2;
if (dest<src)
__asm__ __volatile__(
        "cld\n\t"
        "rep\n\t"
        "movsb"
        : "=&c" (d0), "=&S" (d1), "=&D" (d2)
        :"0" (n),"1" (src),"2" (dest)
        : "memory");
else
__asm__ __volatile__(
        "std\n\t"
        "rep\n\t"
        "movsb\n\t"
        "cld"
        : "=&c" (d0), "=&S" (d1), "=&D" (d2)
        :"0" (n),
         "1" (n-1+(const char *)src),
         "2" (n-1+(char *)dest)
        :"memory");
return dest;
}

#define memcmp __builtin_memcmp

#define __HAVE_ARCH_MEMCHR
extern inline void * memchr(const void * cs,int c,size_t count)
{
int d0;
register void * __res;
if (!count)
        return NULL;
__asm__ __volatile__(
        "cld\n\t"
        "repne\n\t"
        "scasb\n\t"
        "je 1f\n\t"
        "movl $1,%0\n"
        "1:\tdecl %0"
        :"=D" (__res), "=&c" (d0) : "a" (c),"0" (cs),"1" (count));
return __res;
}

extern inline void * __memset_generic(void * s, char c,size_t count)
{
int d0, d1;
__asm__ __volatile__(
        "cld\n\t"
        "rep\n\t"
        "stosb"
        : "=&c" (d0), "=&D" (d1)
        :"a" (c),"1" (s),"0" (count)
        :"memory");
return s;
}

/* we might want to write optimized versions of these later */
#define __constant_count_memset(s,c,count) __memset_generic((s),(c),(count))

/*
 * memset(x,0,y) is a reasonably common thing to do, so we want to fill
 * things 32 bits at a time even when we don't know the size of the
 * area at compile-time..
 */

extern inline void * __constant_c_memset(void * s, unsigned long c, size_t count)
{
int d0, d1;
__asm__ __volatile__(
        "cld\n\t"
        "rep ; stosl\n\t"
        "testb $2,%b3\n\t"
        "je 1f\n\t"
        "stosw\n"
        "1:\ttestb $1,%b3\n\t"
        "je 2f\n\t"
        "stosb\n"
        "2:"
        : "=&c" (d0), "=&D" (d1)
        :"a" (c), "q" (count), "0" (count/4), "1" ((long) s)
        :"memory");
return (s);    
}

/*
 * This looks horribly ugly, but the compiler can optimize it totally,
 * as we by now know that both pattern and count is constant..
 */

extern inline void * __constant_c_and_count_memset(void * s, unsigned long pattern, size_t count)
{
        switch (count) {
                case 0:
                        return s;
                case 1:
                        *(unsigned char *)s = pattern;
                        return s;
                case 2:
                        *(unsigned short *)s = pattern;
                        return s;
                case 3:
                        *(unsigned short *)s = pattern;
                        *(2+(unsigned char *)s) = pattern;
                        return s;
                case 4:
                        *(unsigned long *)s = pattern;
                        return s;
        }
#define COMMON(x) \
__asm__  __volatile__("cld\n\t" \
        "rep ; stosl" \
        x \
        : "=&c" (d0), "=&D" (d1) \
        : "a" (pattern),"0" (count/4),"1" ((long) s) \
        : "memory")

{
        int d0, d1;
        switch (count % 4) {
                case 0: COMMON(""); return s;
                case 1: COMMON("\n\tstosb"); return s;
                case 2: COMMON("\n\tstosw"); return s;
                default: COMMON("\n\tstosw\n\tstosb"); return s;
        }
}
 
#undef COMMON
}

#define __constant_c_x_memset(s, c, count) \
(__builtin_constant_p(count) ? \
 __constant_c_and_count_memset((s),(c),(count)) : \
 __constant_c_memset((s),(c),(count)))


#define __memset(s, c, count) \
(__builtin_constant_p(count) ? \
 __constant_count_memset((s),(c),(count)) : \
 __memset_generic((s),(c),(count)))


#define __HAVE_ARCH_MEMSET
#define memset(s, c, count) \
(__builtin_constant_p(c) ? \
 __constant_c_x_memset((s),(0x01010101UL*(unsigned char)c),(count)) : \
 __memset((s),(c),(count)))


/*
 * find the first occurrence of byte 'c', or 1 past the area if none
 */

#define __HAVE_ARCH_MEMSCAN
extern inline void * memscan(void * addr, int c, size_t size)
{
        if (!size)
                return addr;
        __asm__("cld
                repnz; scasb
                jnz 1f
                dec %%edi
1:              "

                : "=D" (addr), "=c" (size)
                : "0" (addr), "1" (size), "a" (c));
        return addr;
}

void fmemcpy(unsigned short ds,unsigned long dof,unsigned short ss,unsigned long sof,unsigned n);
#if 0
extern inline void fmemcpy(unsigned short ds,unsigned long dof,unsigned short ss,unsigned long sof,unsigned n)
{
        /* Build the standard stack frame */
__asm__ __volatile__(
                /* Get parms into register */
                movl    8(%ebp),%eax
                movw    %ax,%es
                movl    12(%ebp),%edi
                movl    16(%ebp),%eax
                movw    %ax,%ds
                movl    20(%ebp),%esi          
                movl    24(%ebp),%ecx
                cld
                rep
                "movsb"

        "2:"
        : "=&c" (d0), "=&D" (d1), "=&S" (d2)
        :"0" (n), "q" (n),"1" ((long) to),"2" ((long) from)
        : "memory");

);


                popw    %es
                popw    %ds    
                popl    %edi
                popl    %esi           
                leave
                ret

#endif

END_DEF

#endif