/* * Mach Operating System * Copyright (c) 1991,1990 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * HISTORY * $Log: db_access.c,v $ * Revision 1.1.1.1 1993/03/21 09:45:37 cgd * initial import of 386bsd-0.1 sources * * Revision 1.1 1992/03/25 21:44:50 pace * Initial revision * * Revision 2.3 91/02/05 17:05:44 mrt * Changed to new Mach copyright * [91/01/31 16:16:22 mrt] * * Revision 2.2 90/08/27 21:48:20 dbg * Fix type declarations. * [90/08/07 dbg] * Created. * [90/07/25 dbg] * */ /* * Author: David B. Golub, Carnegie Mellon University * Date: 7/90 */ #include "param.h" #include "proc.h" #include /* type definitions */ /* * Access unaligned data items on aligned (longword) * boundaries. */ extern void db_read_bytes(); /* machine-dependent */ extern void db_write_bytes(); /* machine-dependent */ int db_extend[] = { /* table for sign-extending */ 0, 0xFFFFFF80, 0xFFFF8000, 0xFF800000 }; db_expr_t db_get_value(addr, size, is_signed) db_addr_t addr; register int size; boolean_t is_signed; { char data[sizeof(int)]; register db_expr_t value; register int i; db_read_bytes(addr, size, data); value = 0; #if BYTE_MSF for (i = 0; i < size; i++) #else /* BYTE_LSF */ for (i = size - 1; i >= 0; i--) #endif { value = (value << 8) + (data[i] & 0xFF); } if (size < 4) { if (is_signed && (value & db_extend[size]) != 0) value |= db_extend[size]; } return (value); } void db_put_value(addr, size, value) db_addr_t addr; register int size; register db_expr_t value; { char data[sizeof(int)]; register int i; #if BYTE_MSF for (i = size - 1; i >= 0; i--) #else /* BYTE_LSF */ for (i = 0; i < size; i++) #endif { data[i] = value & 0xFF; value >>= 8; } db_write_bytes(addr, size, data); }