1 /*
2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 package jdk.tools.jaotc.binformat.elf;
25
26 /**
27 *
28 * Support for the creation of Elf Object files. Current support is limited to 64 bit x86_64.
29 *
30 */
31
32 final class Elf {
33 //@formatter:off
34 /**
35 * Elf64_Ehdr structure defines
36 */
37 enum Elf64_Ehdr {
38 e_ident( 0,16),
39 e_type(16, 2),
40 e_machine(18, 2),
41 e_version(20, 4),
42 e_entry(24, 8),
43 e_phoff(32, 8),
44 e_shoff(40, 8),
45 e_flags(48, 4),
46 e_ehsize(52, 2),
47 e_phentsize(54, 2),
48 e_phnum(56, 2),
49 e_shentsize(58, 2),
50 e_shnum(60, 2),
51 e_shstrndx(62, 2);
52
53 final int off;
54 final int sz;
55
56 Elf64_Ehdr(int offset, int size) {
57 this.off = offset;
58 this.sz = size;
59 }
60
61 static int totalsize = 64;
62
63 /**
64 * Elf64_Ehdr defines
65 */
66
67 /**
68 * e_ident
69 */
70 static final int EI_MAG0 = 0;
71 static final byte ELFMAG0 = 0x7f;
72 static final int EI_MAG1 = 1;
73 static final byte ELFMAG1 = 0x45;
74 static final int EI_MAG2 = 2;
75 static final byte ELFMAG2 = 0x4c;
76 static final int EI_MAG3 = 3;
77 static final byte ELFMAG3 = 0x46;
78 static final int EI_CLASS = 4;
79 static final byte ELFCLASS64 = 0x2;
80
81 static final int EI_DATA = 5;
82 static final byte ELFDATA2LSB = 0x1;
83
84 static final int EI_VERSION = 6;
85 static final byte EV_CURRENT = 0x1;
86
87 static final int EI_OSABI = 7;
88 static final byte ELFOSABI_NONE = 0x0;
89
90 /**
91 * e_type
92 */
93 static final char ET_REL = 0x1;
94
95 /**
96 * e_machine
97 */
98 static final char EM_NONE = 0;
99 static final char EM_X86_64 = 62;
100 static final char EM_AARCH64 = 183;
101
102 }
103
104 /**
105 * Elf64_Shdr structure defines
106 */
107 enum Elf64_Shdr {
108 sh_name( 0, 4),
109 sh_type( 4, 4),
110 sh_flags( 8, 8),
111 sh_addr(16, 8),
112 sh_offset(24, 8),
113 sh_size(32, 8),
114 sh_link(40, 4),
115 sh_info(44, 4),
116 sh_addralign(48, 8),
117 sh_entsize(56, 8);
118
119 final int off;
120 final int sz;
121
122 Elf64_Shdr(int offset, int size) {
123 this.off = offset;
124 this.sz = size;
125 }
126
127 static int totalsize = 64;
128
129 /**
130 * Elf64_Shdr defines
131 */
132
133 /**
134 * sh_type
135 */
136 static final int SHT_PROGBITS = 0x1;
137 static final int SHT_SYMTAB = 0x2;
138 static final int SHT_STRTAB = 0x3;
139 static final int SHT_RELA = 0x4;
140 static final int SHT_NOBITS = 0x8;
141 static final int SHT_REL = 0x9;
142
143 static final byte SHN_UNDEF = 0x0;
144
145 /**
146 * sh_flag
147 */
148 static final int SHF_WRITE = 0x1;
149 static final int SHF_ALLOC = 0x2;
150 static final int SHF_EXECINSTR = 0x4;
151
152 }
153
154 /**
155 * Symbol table entry definitions
156 *
157 * Elf64_Sym structure defines
158 */
159 enum Elf64_Sym {
160 st_name( 0, 4),
161 st_info( 4, 1),
162 st_other( 5, 1),
163 st_shndx( 6, 2),
164 st_value( 8, 8),
165 st_size(16, 8);
166
167 final int off;
168 final int sz;
169
170 Elf64_Sym(int offset, int size) {
171 this.off = offset;
172 this.sz = size;
173 }
174
175 static int totalsize = 24;
176
177 /* ST_BIND is in bits 4-7 of st_info. ST_TYPE is in low 4 bits */
178 static final byte STB_LOCAL = 0x0;
179 static final byte STB_GLOBAL = 0x1;
180
181 static final byte STT_NOTYPE = 0x0;
182 static final byte STT_OBJECT = 0x1;
183 static final byte STT_FUNC = 0x2;
184
185 static byte ELF64_ST_INFO(byte bind, byte type) {
186 return (byte)(((bind) << 4) + ((type) & 0xf));
187 }
188
189 }
190
191 /**
192 * Elf64_Rel structure defines
193 */
194 enum Elf64_Rel {
195 r_offset( 0, 8),
196 r_info( 8, 8);
197
198 final int off;
199 final int sz;
200
201 Elf64_Rel(int offset, int size) {
202 this.off = offset;
203 this.sz = size;
204 }
205
206 static int totalsize = 16;
207
208 /**
209 * Relocation types
210 */
211 static final int R_X86_64_NONE = 0x0;
212 static final int R_X86_64_64 = 0x1;
213 static final int R_X86_64_PC32 = 0x2;
214 static final int R_X86_64_PLT32 = 0x4;
215 static final int R_X86_64_GOTPCREL = 0x9;
216
217 }
218
219 /**
220 * Elf64_Rela structure defines
221 */
222 enum Elf64_Rela {
223 r_offset( 0, 8),
224 r_info( 8, 8),
225 r_addend(16, 8);
226
227 final int off;
228 final int sz;
229
230 Elf64_Rela(int offset, int size) {
231 this.off = offset;
232 this.sz = size;
233 }
234
235 static int totalsize = 24;
236
237 static final int R_X86_64_NONE = 0x0;
238 static final int R_X86_64_64 = 0x1;
239 static final int R_X86_64_PC32 = 0x2;
240 static final int R_X86_64_PLT32 = 0x4;
241 static final int R_X86_64_GOTPCREL = 0x9;
242
243 static long ELF64_R_INFO(int symidx, int type) {
244 return (((long)symidx << 32) + type);
245 }
246
247 }
248 //@formatter:on
249 }