Return to db_access.c CVS log

Up to [Net/2] / Net2 / ddb

Annotation of Net2/ddb/db_access.c, revision 1.1

1.1     ! root        1: /* 
        !             2:  * Mach Operating System
        !             3:  * Copyright (c) 1991,1990 Carnegie Mellon University
        !             4:  * All Rights Reserved.
        !             5:  * 
        !             6:  * Permission to use, copy, modify and distribute this software and its
        !             7:  * documentation is hereby granted, provided that both the copyright
        !             8:  * notice and this permission notice appear in all copies of the
        !             9:  * software, derivative works or modified versions, and any portions
        !            10:  * thereof, and that both notices appear in supporting documentation.
        !            11:  * 
        !            12:  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 
        !            13:  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
        !            14:  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
        !            15:  * 
        !            16:  * Carnegie Mellon requests users of this software to return to
        !            17:  * 
        !            18:  *  Software Distribution Coordinator  or  [email protected]
        !            19:  *  School of Computer Science
        !            20:  *  Carnegie Mellon University
        !            21:  *  Pittsburgh PA 15213-3890
        !            22:  * 
        !            23:  * any improvements or extensions that they make and grant Carnegie the
        !            24:  * rights to redistribute these changes.
        !            25:  */
        !            26: /*
        !            27:  * HISTORY
        !            28:  * $Log: db_access.c,v $
        !            29:  * Revision 1.1  1992/03/25  21:44:50  pace
        !            30:  * Initial revision
        !            31:  *
        !            32:  * Revision 2.3  91/02/05  17:05:44  mrt
        !            33:  *     Changed to new Mach copyright
        !            34:  *     [91/01/31  16:16:22  mrt]
        !            35:  * 
        !            36:  * Revision 2.2  90/08/27  21:48:20  dbg
        !            37:  *     Fix type declarations.
        !            38:  *     [90/08/07            dbg]
        !            39:  *     Created.
        !            40:  *     [90/07/25            dbg]
        !            41:  * 
        !            42:  */
        !            43: /*
        !            44:  *     Author: David B. Golub, Carnegie Mellon University
        !            45:  *     Date:   7/90
        !            46:  */
        !            47: #include "param.h"
        !            48: #include "proc.h"
        !            49: #include <machine/db_machdep.h>                /* type definitions */
        !            50: 
        !            51: /*
        !            52:  * Access unaligned data items on aligned (longword)
        !            53:  * boundaries.
        !            54:  */
        !            55: 
        !            56: extern void    db_read_bytes();        /* machine-dependent */
        !            57: extern void    db_write_bytes();       /* machine-dependent */
        !            58: 
        !            59: int db_extend[] = {    /* table for sign-extending */
        !            60:        0,
        !            61:        0xFFFFFF80,
        !            62:        0xFFFF8000,
        !            63:        0xFF800000
        !            64: };
        !            65: 
        !            66: db_expr_t
        !            67: db_get_value(addr, size, is_signed)
        !            68:        db_addr_t       addr;
        !            69:        register int    size;
        !            70:        boolean_t       is_signed;
        !            71: {
        !            72:        char            data[sizeof(int)];
        !            73:        register db_expr_t value;
        !            74:        register int    i;
        !            75: 
        !            76:        db_read_bytes(addr, size, data);
        !            77: 
        !            78:        value = 0;
        !            79: #if    BYTE_MSF
        !            80:        for (i = 0; i < size; i++)
        !            81: #else  /* BYTE_LSF */
        !            82:        for (i = size - 1; i >= 0; i--)
        !            83: #endif
        !            84:        {
        !            85:            value = (value << 8) + (data[i] & 0xFF);
        !            86:        }
        !            87:            
        !            88:        if (size < 4) {
        !            89:            if (is_signed && (value & db_extend[size]) != 0)
        !            90:                value |= db_extend[size];
        !            91:        }
        !            92:        return (value);
        !            93: }
        !            94: 
        !            95: void
        !            96: db_put_value(addr, size, value)
        !            97:        db_addr_t       addr;
        !            98:        register int    size;
        !            99:        register db_expr_t value;
        !           100: {
        !           101:        char            data[sizeof(int)];
        !           102:        register int    i;
        !           103: 
        !           104: #if    BYTE_MSF
        !           105:        for (i = size - 1; i >= 0; i--)
        !           106: #else  /* BYTE_LSF */
        !           107:        for (i = 0; i < size; i++)
        !           108: #endif
        !           109:        {
        !           110:            data[i] = value & 0xFF;
        !           111:            value >>= 8;
        !           112:        }
        !           113: 
        !           114:        db_write_bytes(addr, size, data);
        !           115: }
        !           116: 

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.