usr/src/common/sgsrtcid/sgsrtcid.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SGSRTCID_H
  27 #define _SGSRTCID_H
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 #ifdef  __cplusplus
  32 extern "C" {
  33 #endif
  34
  35
  36 /*
  37  * This file defines the Rtc_id structure that is found at the beginning
  38  * of linker configuration files. It resides at this level so that
  39  * it can be accessed by file(1) as well as by crle(1) and the
  40  * runtime linker (ld.so.1). The rest of the data structures for
  41  * config files are found in usr/src/cmd/sgs/include/rtc.h
  42  *
  43  * The use of sizeof(char) data (no byte order issue) and explicit
  44  * padding in the definition of Rtc_id ensures that it will have
  45  * exactly the same layout on all systems, and will have a
  46  * size of 16 bytes. The same layout means all systems can read it.
  47  * the same size means that any data can be safely placed immediately
  48  * following it, without the need for alignment.
  49  */
  50
  51 /*
  52  * Identification header.
  53  */
  54 typedef struct {
  55         uchar_t id_magic0;      /* RTC_ID_MAG0 */
  56         uchar_t id_magic1;      /* RTC_ID_MAG1 */
  57         uchar_t id_magic2;      /* RTC_ID_MAG2 */
  58         uchar_t id_magic3;      /* RTC_ID_MAG0 */
  59         uchar_t id_class;       /* File class/capacity (ELFCLASS constant) */
  60         uchar_t id_data;        /* Data encoding (ELFDATA constant) */
  61         uchar_t id_machine;     /* Architecture (ELF EM_ constant) */
  62         uchar_t id_pad[9];      /* Ensure size is 16 bytes */
  63 } Rtc_id;
  64
  65 #define RTC_ID_MAG0 '\077'      /* ? */
  66 #define RTC_ID_MAG1 'R'         /* Runtime */
  67 #define RTC_ID_MAG2 'L'         /* Linker */
  68 #define RTC_ID_MAG3 'C'         /* Configuration */
  69
  70 /*
  71  * Ensure that the largest machine constant will not grow beyond
  72  * maximum value representable by an unsigned byte without our
  73  * being alerted to it.
  74  */
  75 #if EM_NUM > 256
  76 #error "Maximum machine constant size exceeded. Format requires revision."
  77 #endif
  78
  79 /*
  80  * Check the 4 bytes starting at the given address to see if
  81  * they contain the Rtc_id magic number. The type of the address
  82  * is unimportant as long as it is valid, because RTC_ID_TEST()
  83  * will cast it to (uchar_t *).
  84  */
  85 #define RTC_ID_TEST(addr) \
  86         ((RTC_ID_MAG0 == *((uchar_t *)addr)) && \
  87         (RTC_ID_MAG1 == *(((uchar_t *)addr) + 1)) && \
  88         (RTC_ID_MAG2 == *(((uchar_t *)addr) + 2)) && \
  89         (RTC_ID_MAG3 == *(((uchar_t *)addr) + 3)))
  90
  91 #ifdef  __cplusplus
  92 }
  93 #endif
  94
  95 #endif  /* _SGSRTCID_H */