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/* Project:     OSLib
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 * Description: The OS Construction Kit
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 * Date:                1.6.2000
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 * Idea by:             Luca Abeni & Gerardo Lamastra
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 *
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 * OSLib is an SO project aimed at developing a common, easy-to-use
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 * low-level infrastructure for developing OS kernels and Embedded
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 * Applications; it partially derives from the HARTIK project but it
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 * currently is independently developed.
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 *
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 * OSLib is distributed under GPL License, and some of its code has
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 * been derived from the Linux kernel source; also some important
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 * ideas come from studying the DJGPP go32 extender.
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 *
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 * We acknowledge the Linux Community, Free Software Foundation,
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 * D.J. Delorie and all the other developers who believe in the
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 * freedom of software and ideas.
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 *
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 * For legalese, check out the included GPL license.
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 */
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/*      Basic Memory Manager Functions:
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        A classic fixed partition allocator!    */
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#include <ll/i386/stdlib.h>
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#include <ll/i386/string.h>
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#include <ll/i386/mem.h>
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#include <ll/i386/cons.h>
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#include <ll/i386/error.h>
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#include <ll/sys/ll/ll-mem.h>
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FILE(Memory);
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#define MAX_PARTITION   50      /* Max available partition */
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static struct {
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    BYTE used;
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#ifdef __WC16__
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    BYTE __huge *addr;
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#else
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    BYTE *addr;
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#endif
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    DWORD size;
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} mem_table[MAX_PARTITION];
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void ll_mem_init(void *base, DWORD size)
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{
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    register int i;
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    mem_table[0].used = 1;
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    mem_table[0].addr = base;
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    mem_table[0].size = size;
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    for (i = 1; i < MAX_PARTITION; i++)
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        mem_table[i].used = 0;
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}
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void *ll_alloc(DWORD s)
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{
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    void *p = NULL;
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    int i = 0;
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    while (i < MAX_PARTITION && p == NULL) {
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        if (mem_table[i].used && (mem_table[i].size >= s))
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            p = mem_table[i].addr;
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        else
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            i++;
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    }
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    if (p != NULL) {
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        if (mem_table[i].size > s) {
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            mem_table[i].size -= s;
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            mem_table[i].addr += s;
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        } else
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            mem_table[i].used = FALSE;
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    }
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    return (p);
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}
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WORD ll_free(void *p, DWORD s)
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{
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    register int i = 1;
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    unsigned i1 = 0, i2 = 0;
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    while (i < MAX_PARTITION && ((i1 == 0) || (i2 == 0))) {
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        if (mem_table[i].used) {
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            if (mem_table[i].addr + mem_table[i].size == p)
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                i1 = i;
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            if (mem_table[i].addr == (BYTE *) (p) + s)
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                i2 = i;
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        }
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        i++;
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    }
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    if (i1 != 0 && i2 != 0) {
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        mem_table[i1].size += mem_table[i2].size + s;
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        mem_table[i2].used = FALSE;
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    } else if (i1 == 0 && i2 != 0) {
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        mem_table[i2].addr = p;
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        mem_table[i2].size += s;
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    } else if (i1 != 0 && i2 == 0)
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        mem_table[i1].size += s;
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    else {
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        i = 0;
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        while (i < MAX_PARTITION && (mem_table[i].used == TRUE))
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            i++;
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        if (i == MAX_PARTITION)
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            return (FALSE);
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        mem_table[i].addr = p;
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        mem_table[i].size = s;
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        mem_table[i].used = TRUE;
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    }
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    return (TRUE);
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}
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void ll_mem_dump(void)
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{
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    register int i;
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    for (i = 0; i < MAX_PARTITION; i++) {
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        if (mem_table[i].used)
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            message("Entry : [%d] Addr : %p Size : %ld\n", i,
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                    mem_table[i].addr, mem_table[i].size);
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    }
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}