001 // This file is part of the program FRYSK.
002 //
003 // Copyright 2005, 2008, Red Hat Inc.
004 //
005 // FRYSK is free software; you can redistribute it and/or modify it
006 // under the terms of the GNU General Public License as published by
007 // the Free Software Foundation; version 2 of the License.
008 //
009 // FRYSK is distributed in the hope that it will be useful, but
010 // WITHOUT ANY WARRANTY; without even the implied warranty of
011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 // General Public License for more details.
013 //
014 // You should have received a copy of the GNU General Public License
015 // along with FRYSK; if not, write to the Free Software Foundation,
016 // Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
017 //
018 // In addition, as a special exception, Red Hat, Inc. gives You the
019 // additional right to link the code of FRYSK with code not covered
020 // under the GNU General Public License ("Non-GPL Code") and to
021 // distribute linked combinations including the two, subject to the
022 // limitations in this paragraph. Non-GPL Code permitted under this
023 // exception must only link to the code of FRYSK through those well
024 // defined interfaces identified in the file named EXCEPTION found in
025 // the source code files (the "Approved Interfaces"). The files of
026 // Non-GPL Code may instantiate templates or use macros or inline
027 // functions from the Approved Interfaces without causing the
028 // resulting work to be covered by the GNU General Public
029 // License. Only Red Hat, Inc. may make changes or additions to the
030 // list of Approved Interfaces. You must obey the GNU General Public
031 // License in all respects for all of the FRYSK code and other code
032 // used in conjunction with FRYSK except the Non-GPL Code covered by
033 // this exception. If you modify this file, you may extend this
034 // exception to your version of the file, but you are not obligated to
035 // do so. If you do not wish to provide this exception without
036 // modification, you must delete this exception statement from your
037 // version and license this file solely under the GPL without
038 // exception.
039
040 package lib.dwfl;
041
042 import inua.eio.ByteOrder;
043
044 /**
045 * An ElfEHeader is a header for and Elf file. This appears at the
046 * start of every Elf file.
047 */
048 public final class ElfEHeader {
049
050 public ElfEHeader(){
051 }
052
053 // Version
054 //public static final int PHEADER_EV_VERSION = parent.getElfVersion();
055
056 // ident[CLASS} contains the word-size
057 public static final int CLASSNONE = 0;
058 public static final int CLASS32 = 1;
059 public static final int CLASS64 = 2;
060 public final static int CLASS = 4;
061
062 // Data class
063 public static final int DATANONE = 0;
064 public static final int DATA2LSB = 1;
065 public static final int DATA2MSB = 2;
066 public static final int DATA = 5;
067
068 // Type
069 public static final int PHEADER_ET_NONE = 0;
070 public static final int PHEADER_ET_REL = 1;
071 public static final int PHEADER_ET_EXEC = 2;
072 public static final int PHEADER_ET_DYN = 3;
073 public static final int PHEADER_ET_CORE = 4;
074 public static final int PHEADER_ET_NUM = 5;
075 public static final int PHEADER_ET_LOOS = 0xfe00;
076 public static final int PHEADER_ET_HIOS = 0xfeff;
077 public static final int PHEADER_ET_LOPROC = 0xff00;
078 public static final int PHEADER_ET_HIPROC = 0xffff;
079
080 public static final int NIDENT = 16;
081 public byte[] ident = new byte[NIDENT];
082
083 public int type;
084 public int machine;
085 public long version;
086 public long entry;
087 public long phoff;
088 public long shoff;
089 public int flags;
090 public int ehsize;
091 public int phentsize;
092 public int phnum;
093 public int shentsize;
094 public int shnum;
095 public int shstrndx;
096
097 /**
098 * Interpret the IDENT field; extracting the word-size.
099 */
100 public int getWordSize() {
101 switch (ident[CLASS]) {
102 case CLASSNONE:
103 return 0;
104 case CLASS32:
105 return 4;
106 case CLASS64:
107 return 8;
108 default:
109 // This is a programmer error; not a an Elf file or format error.
110 throw new RuntimeException("Unknown ELF class " + ident[CLASS]);
111 }
112 }
113
114 /**
115 * Encode SIZE into the IDENT field.
116 */
117 public ElfEHeader setWordSize(int size) {
118 switch (size) {
119 case 0:
120 ident[CLASS] = CLASSNONE;
121 return this;
122 case 4:
123 ident[CLASS] = CLASS32;
124 return this;
125 case 8:
126 ident[CLASS] = CLASS64;
127 return this;
128 default:
129 // This is a programmer error; not an Elf file format error.
130 throw new RuntimeException("No class for word-size " + size);
131 }
132 }
133
134 /**
135 * Interpret the IDENT field; extracting the byte order.
136 */
137 public ByteOrder getByteOrder() {
138 switch (ident[DATA]) {
139 case DATANONE:
140 return null;
141 case DATA2LSB:
142 return ByteOrder.LITTLE_ENDIAN;
143 case DATA2MSB:
144 return ByteOrder.BIG_ENDIAN;
145 default:
146 // This is a programmer error; not a an Elf file or format error.
147 throw new RuntimeException("Unknown ELF class " + ident[DATA]);
148 }
149 }
150
151 /**
152 * Encode SIZE into the IDENT field.
153 */
154 public ElfEHeader setByteOrder(ByteOrder order) {
155 if (order == null)
156 ident[DATA] = DATANONE;
157 else if (order == ByteOrder.LITTLE_ENDIAN)
158 ident[DATA] = DATA2LSB;
159 else if (order == ByteOrder.BIG_ENDIAN)
160 ident[DATA] = DATA2MSB;
161 else
162 // This is a programmer error; not an Elf file format error.
163 throw new RuntimeException("No data for byte-order " + order);
164 return this;
165 }
166 }