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Source at commit 2741 created 8 years 11 months ago. By ifabio, Add data for new logo and clut (grey) from macosxbootloader (Credits to Pike R. Alpha) | |
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1 | /*␊ |
2 | * Copyright (c) 1999-2010 Apple Inc. All Rights Reserved.␊ |
3 | *␊ |
4 | * @APPLE_LICENSE_HEADER_START@␊ |
5 | * ␊ |
6 | * This file contains Original Code and/or Modifications of Original Code␊ |
7 | * as defined in and that are subject to the Apple Public Source License␊ |
8 | * Version 2.0 (the 'License'). You may not use this file except in␊ |
9 | * compliance with the License. Please obtain a copy of the License at␊ |
10 | * http://www.opensource.apple.com/apsl/ and read it before using this␊ |
11 | * file.␊ |
12 | * ␊ |
13 | * The Original Code and all software distributed under the License are␊ |
14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER␊ |
15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,␊ |
16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,␊ |
17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.␊ |
18 | * Please see the License for the specific language governing rights and␊ |
19 | * limitations under the License.␊ |
20 | * ␊ |
21 | * @APPLE_LICENSE_HEADER_END@␊ |
22 | */␊ |
23 | #ifndef _MACHO_LOADER_H_␊ |
24 | #define _MACHO_LOADER_H_␊ |
25 | ␊ |
26 | /*␊ |
27 | * This file describes the format of mach object files.␊ |
28 | */␊ |
29 | #include <stdint.h>␊ |
30 | ␊ |
31 | /*␊ |
32 | * <mach/machine.h> is needed here for the cpu_type_t and cpu_subtype_t types␊ |
33 | * and contains the constants for the possible values of these types.␊ |
34 | */␊ |
35 | #include <mach/machine.h>␊ |
36 | ␊ |
37 | /*␊ |
38 | * <mach/vm_prot.h> is needed here for the vm_prot_t type and contains the ␊ |
39 | * constants that are or'ed together for the possible values of this type.␊ |
40 | */␊ |
41 | #include <mach/vm_prot.h>␊ |
42 | ␊ |
43 | /*␊ |
44 | * <machine/thread_status.h> is expected to define the flavors of the thread␊ |
45 | * states and the structures of those flavors for each machine.␊ |
46 | */␊ |
47 | #include <mach/machine/thread_status.h>␊ |
48 | #include <architecture/byte_order.h>␊ |
49 | ␊ |
50 | /*␊ |
51 | * The 32-bit mach header appears at the very beginning of the object file for␊ |
52 | * 32-bit architectures.␊ |
53 | */␊ |
54 | struct mach_header {␊ |
55 | ␉uint32_t␉magic;␉␉/* mach magic number identifier */␊ |
56 | ␉cpu_type_t␉cputype;␉/* cpu specifier */␊ |
57 | ␉cpu_subtype_t␉cpusubtype;␉/* machine specifier */␊ |
58 | ␉uint32_t␉filetype;␉/* type of file */␊ |
59 | ␉uint32_t␉ncmds;␉␉/* number of load commands */␊ |
60 | ␉uint32_t␉sizeofcmds;␉/* the size of all the load commands */␊ |
61 | ␉uint32_t␉flags;␉␉/* flags */␊ |
62 | };␊ |
63 | ␊ |
64 | /* Constant for the magic field of the mach_header (32-bit architectures) */␊ |
65 | #define␉MH_MAGIC␉0xfeedface␉/* the mach magic number */␊ |
66 | #define MH_CIGAM␉0xcefaedfe␉/* NXSwapInt(MH_MAGIC) */␊ |
67 | ␊ |
68 | /*␊ |
69 | * The 64-bit mach header appears at the very beginning of object files for␊ |
70 | * 64-bit architectures.␊ |
71 | */␊ |
72 | struct mach_header_64 {␊ |
73 | ␉uint32_t␉magic;␉␉/* mach magic number identifier */␊ |
74 | ␉cpu_type_t␉cputype;␉/* cpu specifier */␊ |
75 | ␉cpu_subtype_t␉cpusubtype;␉/* machine specifier */␊ |
76 | ␉uint32_t␉filetype;␉/* type of file */␊ |
77 | ␉uint32_t␉ncmds;␉␉/* number of load commands */␊ |
78 | ␉uint32_t␉sizeofcmds;␉/* the size of all the load commands */␊ |
79 | ␉uint32_t␉flags;␉␉/* flags */␊ |
80 | ␉uint32_t␉reserved;␉/* reserved */␊ |
81 | };␊ |
82 | ␊ |
83 | /* Constant for the magic field of the mach_header_64 (64-bit architectures) */␊ |
84 | #define MH_MAGIC_64 0xfeedfacf /* the 64-bit mach magic number */␊ |
85 | #define MH_CIGAM_64 0xcffaedfe /* NXSwapInt(MH_MAGIC_64) */␊ |
86 | ␊ |
87 | /*␊ |
88 | * The layout of the file depends on the filetype. For all but the MH_OBJECT␊ |
89 | * file type the segments are padded out and aligned on a segment alignment␊ |
90 | * boundary for efficient demand pageing. The MH_EXECUTE, MH_FVMLIB, MH_DYLIB,␊ |
91 | * MH_DYLINKER and MH_BUNDLE file types also have the headers included as part␊ |
92 | * of their first segment.␊ |
93 | * ␊ |
94 | * The file type MH_OBJECT is a compact format intended as output of the␊ |
95 | * assembler and input (and possibly output) of the link editor (the .o␊ |
96 | * format). All sections are in one unnamed segment with no segment padding. ␊ |
97 | * This format is used as an executable format when the file is so small the␊ |
98 | * segment padding greatly increases its size.␊ |
99 | *␊ |
100 | * The file type MH_PRELOAD is an executable format intended for things that␊ |
101 | * are not executed under the kernel (proms, stand alones, kernels, etc). The␊ |
102 | * format can be executed under the kernel but may demand paged it and not␊ |
103 | * preload it before execution.␊ |
104 | *␊ |
105 | * A core file is in MH_CORE format and can be any in an arbritray legal␊ |
106 | * Mach-O file.␊ |
107 | *␊ |
108 | * Constants for the filetype field of the mach_header␊ |
109 | */␊ |
110 | #define␉MH_OBJECT␉0x1␉␉/* relocatable object file */␊ |
111 | #define␉MH_EXECUTE␉0x2␉␉/* demand paged executable file */␊ |
112 | #define␉MH_FVMLIB␉0x3␉␉/* fixed VM shared library file */␊ |
113 | #define␉MH_CORE␉␉0x4␉␉/* core file */␊ |
114 | #define␉MH_PRELOAD␉0x5␉␉/* preloaded executable file */␊ |
115 | #define␉MH_DYLIB␉0x6␉␉/* dynamically bound shared library */␊ |
116 | #define␉MH_DYLINKER␉0x7␉␉/* dynamic link editor */␊ |
117 | #define␉MH_BUNDLE␉0x8␉␉/* dynamically bound bundle file */␊ |
118 | #define␉MH_DYLIB_STUB␉0x9␉␉/* shared library stub for static */␊ |
119 | ␉␉␉␉␉/* linking only, no section contents */␊ |
120 | #define␉MH_DSYM␉␉0xa␉␉/* companion file with only debug */␊ |
121 | ␉␉␉␉␉/* sections */␊ |
122 | #define␉MH_KEXT_BUNDLE␉0xb␉␉/* x86_64 kexts */␊ |
123 | ␊ |
124 | /* Constants for the flags field of the mach_header */␊ |
125 | #define␉MH_NOUNDEFS␉0x1␉␉/* the object file has no undefined␊ |
126 | ␉␉␉␉␉ references */␊ |
127 | #define␉MH_INCRLINK␉0x2␉␉/* the object file is the output of an␊ |
128 | ␉␉␉␉␉ incremental link against a base file␊ |
129 | ␉␉␉␉␉ and can't be link edited again */␊ |
130 | #define MH_DYLDLINK␉0x4␉␉/* the object file is input for the␊ |
131 | ␉␉␉␉␉ dynamic linker and can't be staticly␊ |
132 | ␉␉␉␉␉ link edited again */␊ |
133 | #define MH_BINDATLOAD␉0x8␉␉/* the object file's undefined␊ |
134 | ␉␉␉␉␉ references are bound by the dynamic␊ |
135 | ␉␉␉␉␉ linker when loaded. */␊ |
136 | #define MH_PREBOUND␉0x10␉␉/* the file has its dynamic undefined␊ |
137 | ␉␉␉␉␉ references prebound. */␊ |
138 | #define MH_SPLIT_SEGS␉0x20␉␉/* the file has its read-only and␊ |
139 | ␉␉␉␉␉ read-write segments split */␊ |
140 | #define MH_LAZY_INIT␉0x40␉␉/* the shared library init routine is␊ |
141 | ␉␉␉␉␉ to be run lazily via catching memory␊ |
142 | ␉␉␉␉␉ faults to its writeable segments␊ |
143 | ␉␉␉␉␉ (obsolete) */␊ |
144 | #define MH_TWOLEVEL␉0x80␉␉/* the image is using two-level name␊ |
145 | ␉␉␉␉␉ space bindings */␊ |
146 | #define MH_FORCE_FLAT␉0x100␉␉/* the executable is forcing all images␊ |
147 | ␉␉␉␉␉ to use flat name space bindings */␊ |
148 | #define MH_NOMULTIDEFS␉0x200␉␉/* this umbrella guarantees no multiple␊ |
149 | ␉␉␉␉␉ defintions of symbols in its␊ |
150 | ␉␉␉␉␉ sub-images so the two-level namespace␊ |
151 | ␉␉␉␉␉ hints can always be used. */␊ |
152 | #define MH_NOFIXPREBINDING 0x400␉/* do not have dyld notify the␊ |
153 | ␉␉␉␉␉ prebinding agent about this␊ |
154 | ␉␉␉␉␉ executable */␊ |
155 | #define MH_PREBINDABLE 0x800 /* the binary is not prebound but can␊ |
156 | ␉␉␉␉␉ have its prebinding redone. only used␊ |
157 | when MH_PREBOUND is not set. */␊ |
158 | #define MH_ALLMODSBOUND 0x1000␉␉/* indicates that this binary binds to␊ |
159 | all two-level namespace modules of␊ |
160 | ␉␉␉␉␉ its dependent libraries. only used␊ |
161 | ␉␉␉␉␉ when MH_PREBINDABLE and MH_TWOLEVEL␊ |
162 | ␉␉␉␉␉ are both set. */ ␊ |
163 | #define MH_SUBSECTIONS_VIA_SYMBOLS 0x2000/* safe to divide up the sections into␊ |
164 | ␉␉␉␉␉ sub-sections via symbols for dead␊ |
165 | ␉␉␉␉␉ code stripping */␊ |
166 | #define MH_CANONICAL 0x4000␉␉/* the binary has been canonicalized␊ |
167 | ␉␉␉␉␉ via the unprebind operation */␊ |
168 | #define MH_WEAK_DEFINES␉0x8000␉␉/* the final linked image contains␊ |
169 | ␉␉␉␉␉ external weak symbols */␊ |
170 | #define MH_BINDS_TO_WEAK 0x10000␉/* the final linked image uses␊ |
171 | ␉␉␉␉␉ weak symbols */␊ |
172 | ␊ |
173 | #define MH_ALLOW_STACK_EXECUTION 0x20000/* When this bit is set, all stacks ␊ |
174 | ␉␉␉␉␉ in the task will be given stack␊ |
175 | ␉␉␉␉␉ execution privilege. Only used in␊ |
176 | ␉␉␉␉␉ MH_EXECUTE filetypes. */␊ |
177 | #define MH_ROOT_SAFE 0x40000 /* When this bit is set, the binary ␊ |
178 | ␉␉␉␉␉ declares it is safe for use in␊ |
179 | ␉␉␉␉␉ processes with uid zero */␊ |
180 | ␊ |
181 | #define MH_SETUID_SAFE 0x80000 /* When this bit is set, the binary ␊ |
182 | ␉␉␉␉␉ declares it is safe for use in␊ |
183 | ␉␉␉␉␉ processes when issetugid() is true */␊ |
184 | ␊ |
185 | #define MH_NO_REEXPORTED_DYLIBS 0x100000 /* When this bit is set on a dylib, ␊ |
186 | ␉␉␉␉␉ the static linker does not need to␊ |
187 | ␉␉␉␉␉ examine dependent dylibs to see␊ |
188 | ␉␉␉␉␉ if any are re-exported */␊ |
189 | #define␉MH_PIE 0x200000␉␉␉/* When this bit is set, the OS will␊ |
190 | ␉␉␉␉␉ load the main executable at a␊ |
191 | ␉␉␉␉␉ random address. Only used in␊ |
192 | ␉␉␉␉␉ MH_EXECUTE filetypes. */␊ |
193 | #define␉MH_DEAD_STRIPPABLE_DYLIB 0x400000 /* Only for use on dylibs. When␊ |
194 | ␉␉␉␉␉ linking against a dylib that␊ |
195 | ␉␉␉␉␉ has this bit set, the static linker␊ |
196 | ␉␉␉␉␉ will automatically not create a␊ |
197 | ␉␉␉␉␉ LC_LOAD_DYLIB load command to the␊ |
198 | ␉␉␉␉␉ dylib if no symbols are being␊ |
199 | ␉␉␉␉␉ referenced from the dylib. */␊ |
200 | #define MH_HAS_TLV_DESCRIPTORS 0x800000 /* Contains a section of type ␊ |
201 | ␉␉␉␉␉ S_THREAD_LOCAL_VARIABLES */␊ |
202 | ␊ |
203 | #define MH_NO_HEAP_EXECUTION 0x1000000␉/* When this bit is set, the OS will␊ |
204 | ␉␉␉␉␉ run the main executable with␊ |
205 | ␉␉␉␉␉ a non-executable heap even on␊ |
206 | ␉␉␉␉␉ platforms (e.g. i386) that don't␊ |
207 | ␉␉␉␉␉ require it. Only used in MH_EXECUTE␊ |
208 | ␉␉␉␉␉ filetypes. */␊ |
209 | ␊ |
210 | /*␊ |
211 | * The load commands directly follow the mach_header. The total size of all␊ |
212 | * of the commands is given by the sizeofcmds field in the mach_header. All␊ |
213 | * load commands must have as their first two fields cmd and cmdsize. The cmd␊ |
214 | * field is filled in with a constant for that command type. Each command type␊ |
215 | * has a structure specifically for it. The cmdsize field is the size in bytes␊ |
216 | * of the particular load command structure plus anything that follows it that␊ |
217 | * is a part of the load command (i.e. section structures, strings, etc.). To␊ |
218 | * advance to the next load command the cmdsize can be added to the offset or␊ |
219 | * pointer of the current load command. The cmdsize for 32-bit architectures␊ |
220 | * MUST be a multiple of 4 bytes and for 64-bit architectures MUST be a multiple␊ |
221 | * of 8 bytes (these are forever the maximum alignment of any load commands).␊ |
222 | * The padded bytes must be zero. All tables in the object file must also␊ |
223 | * follow these rules so the file can be memory mapped. Otherwise the pointers␊ |
224 | * to these tables will not work well or at all on some machines. With all␊ |
225 | * padding zeroed like objects will compare byte for byte.␊ |
226 | */␊ |
227 | struct load_command {␊ |
228 | ␉uint32_t cmd;␉␉/* type of load command */␊ |
229 | ␉uint32_t cmdsize;␉/* total size of command in bytes */␊ |
230 | };␊ |
231 | ␊ |
232 | /*␊ |
233 | * After MacOS X 10.1 when a new load command is added that is required to be␊ |
234 | * understood by the dynamic linker for the image to execute properly the␊ |
235 | * LC_REQ_DYLD bit will be or'ed into the load command constant. If the dynamic␊ |
236 | * linker sees such a load command it it does not understand will issue a␊ |
237 | * "unknown load command required for execution" error and refuse to use the␊ |
238 | * image. Other load commands without this bit that are not understood will␊ |
239 | * simply be ignored.␊ |
240 | */␊ |
241 | #define LC_REQ_DYLD 0x80000000␊ |
242 | ␊ |
243 | /* Constants for the cmd field of all load commands, the type */␊ |
244 | #define␉LC_SEGMENT␉0x1␉/* segment of this file to be mapped */␊ |
245 | #define␉LC_SYMTAB␉0x2␉/* link-edit stab symbol table info */␊ |
246 | #define␉LC_SYMSEG␉0x3␉/* link-edit gdb symbol table info (obsolete) */␊ |
247 | #define␉LC_THREAD␉0x4␉/* thread */␊ |
248 | #define␉LC_UNIXTHREAD␉0x5␉/* unix thread (includes a stack) */␊ |
249 | #define␉LC_LOADFVMLIB␉0x6␉/* load a specified fixed VM shared library */␊ |
250 | #define␉LC_IDFVMLIB␉0x7␉/* fixed VM shared library identification */␊ |
251 | #define␉LC_IDENT␉0x8␉/* object identification info (obsolete) */␊ |
252 | #define LC_FVMFILE␉0x9␉/* fixed VM file inclusion (internal use) */␊ |
253 | #define LC_PREPAGE 0xa /* prepage command (internal use) */␊ |
254 | #define␉LC_DYSYMTAB␉0xb␉/* dynamic link-edit symbol table info */␊ |
255 | #define␉LC_LOAD_DYLIB␉0xc␉/* load a dynamically linked shared library */␊ |
256 | #define␉LC_ID_DYLIB␉0xd␉/* dynamically linked shared lib ident */␊ |
257 | #define LC_LOAD_DYLINKER 0xe␉/* load a dynamic linker */␊ |
258 | #define LC_ID_DYLINKER␉0xf␉/* dynamic linker identification */␊ |
259 | #define␉LC_PREBOUND_DYLIB 0x10␉/* modules prebound for a dynamically */␊ |
260 | ␉␉␉␉/* linked shared library */␊ |
261 | #define␉LC_ROUTINES␉0x11␉/* image routines */␊ |
262 | #define␉LC_SUB_FRAMEWORK 0x12␉/* sub framework */␊ |
263 | #define␉LC_SUB_UMBRELLA 0x13␉/* sub umbrella */␊ |
264 | #define␉LC_SUB_CLIENT␉0x14␉/* sub client */␊ |
265 | #define␉LC_SUB_LIBRARY 0x15␉/* sub library */␊ |
266 | #define␉LC_TWOLEVEL_HINTS 0x16␉/* two-level namespace lookup hints */␊ |
267 | #define␉LC_PREBIND_CKSUM 0x17␉/* prebind checksum */␊ |
268 | ␊ |
269 | /*␊ |
270 | * load a dynamically linked shared library that is allowed to be missing␊ |
271 | * (all symbols are weak imported).␊ |
272 | */␊ |
273 | #define␉LC_LOAD_WEAK_DYLIB (0x18 | LC_REQ_DYLD)␊ |
274 | ␊ |
275 | #define␉LC_SEGMENT_64␉0x19␉/* 64-bit segment of this file to be␊ |
276 | ␉␉␉␉ mapped */␊ |
277 | #define␉LC_ROUTINES_64␉0x1a␉/* 64-bit image routines */␊ |
278 | #define LC_UUID␉␉0x1b␉/* the uuid */␊ |
279 | #define LC_RPATH (0x1c | LC_REQ_DYLD) /* runpath additions */␊ |
280 | #define LC_CODE_SIGNATURE 0x1d␉/* local of code signature */␊ |
281 | #define LC_SEGMENT_SPLIT_INFO 0x1e /* local of info to split segments */␊ |
282 | #define LC_REEXPORT_DYLIB (0x1f | LC_REQ_DYLD) /* load and re-export dylib */␊ |
283 | #define␉LC_LAZY_LOAD_DYLIB 0x20␉/* delay load of dylib until first use */␊ |
284 | #define␉LC_ENCRYPTION_INFO 0x21␉/* encrypted segment information */␊ |
285 | #define␉LC_DYLD_INFO ␉0x22␉/* compressed dyld information */␊ |
286 | #define␉LC_DYLD_INFO_ONLY (0x22|LC_REQ_DYLD)␉/* compressed dyld information only */␊ |
287 | #define␉LC_LOAD_UPWARD_DYLIB (0x23 | LC_REQ_DYLD) /* load upward dylib */␊ |
288 | #define LC_VERSION_MIN_MACOSX 0x24 /* build for MacOSX min OS version */␊ |
289 | #define LC_VERSION_MIN_IPHONEOS 0x25 /* build for iPhoneOS min OS version */␊ |
290 | #define LC_FUNCTION_STARTS 0x26 /* compressed table of function start addresses */␊ |
291 | #define LC_DYLD_ENVIRONMENT 0x27 /* string for dyld to treat␊ |
292 | ␉␉␉␉ like environment variable */␊ |
293 | ␊ |
294 | /*␊ |
295 | * A variable length string in a load command is represented by an lc_str␊ |
296 | * union. The strings are stored just after the load command structure and␊ |
297 | * the offset is from the start of the load command structure. The size␊ |
298 | * of the string is reflected in the cmdsize field of the load command.␊ |
299 | * Once again any padded bytes to bring the cmdsize field to a multiple␊ |
300 | * of 4 bytes must be zero.␊ |
301 | */␊ |
302 | union lc_str {␊ |
303 | ␉uint32_t␉offset;␉/* offset to the string */␊ |
304 | #ifndef __LP64__␊ |
305 | ␉char␉␉*ptr;␉/* pointer to the string */␊ |
306 | #endif ␊ |
307 | };␊ |
308 | ␊ |
309 | /*␊ |
310 | * The segment load command indicates that a part of this file is to be␊ |
311 | * mapped into the task's address space. The size of this segment in memory,␊ |
312 | * vmsize, maybe equal to or larger than the amount to map from this file,␊ |
313 | * filesize. The file is mapped starting at fileoff to the beginning of␊ |
314 | * the segment in memory, vmaddr. The rest of the memory of the segment,␊ |
315 | * if any, is allocated zero fill on demand. The segment's maximum virtual␊ |
316 | * memory protection and initial virtual memory protection are specified␊ |
317 | * by the maxprot and initprot fields. If the segment has sections then the␊ |
318 | * section structures directly follow the segment command and their size is␊ |
319 | * reflected in cmdsize.␊ |
320 | */␊ |
321 | struct segment_command { /* for 32-bit architectures */␊ |
322 | ␉uint32_t␉cmd;␉␉/* LC_SEGMENT */␊ |
323 | ␉uint32_t␉cmdsize;␉/* includes sizeof section structs */␊ |
324 | ␉char␉␉segname[16];␉/* segment name */␊ |
325 | ␉uint32_t␉vmaddr;␉␉/* memory address of this segment */␊ |
326 | ␉uint32_t␉vmsize;␉␉/* memory size of this segment */␊ |
327 | ␉uint32_t␉fileoff;␉/* file offset of this segment */␊ |
328 | ␉uint32_t␉filesize;␉/* amount to map from the file */␊ |
329 | ␉vm_prot_t␉maxprot;␉/* maximum VM protection */␊ |
330 | ␉vm_prot_t␉initprot;␉/* initial VM protection */␊ |
331 | ␉uint32_t␉nsects;␉␉/* number of sections in segment */␊ |
332 | ␉uint32_t␉flags;␉␉/* flags */␊ |
333 | };␊ |
334 | ␊ |
335 | /*␊ |
336 | * The 64-bit segment load command indicates that a part of this file is to be␊ |
337 | * mapped into a 64-bit task's address space. If the 64-bit segment has␊ |
338 | * sections then section_64 structures directly follow the 64-bit segment␊ |
339 | * command and their size is reflected in cmdsize.␊ |
340 | */␊ |
341 | struct segment_command_64 { /* for 64-bit architectures */␊ |
342 | ␉uint32_t␉cmd;␉␉/* LC_SEGMENT_64 */␊ |
343 | ␉uint32_t␉cmdsize;␉/* includes sizeof section_64 structs */␊ |
344 | ␉char␉␉segname[16];␉/* segment name */␊ |
345 | ␉uint64_t␉vmaddr;␉␉/* memory address of this segment */␊ |
346 | ␉uint64_t␉vmsize;␉␉/* memory size of this segment */␊ |
347 | ␉uint64_t␉fileoff;␉/* file offset of this segment */␊ |
348 | ␉uint64_t␉filesize;␉/* amount to map from the file */␊ |
349 | ␉vm_prot_t␉maxprot;␉/* maximum VM protection */␊ |
350 | ␉vm_prot_t␉initprot;␉/* initial VM protection */␊ |
351 | ␉uint32_t␉nsects;␉␉/* number of sections in segment */␊ |
352 | ␉uint32_t␉flags;␉␉/* flags */␊ |
353 | };␊ |
354 | ␊ |
355 | /* Constants for the flags field of the segment_command */␊ |
356 | #define␉SG_HIGHVM␉0x1␉/* the file contents for this segment is for␊ |
357 | ␉␉␉␉ the high part of the VM space, the low part␊ |
358 | ␉␉␉␉ is zero filled (for stacks in core files) */␊ |
359 | #define␉SG_FVMLIB␉0x2␉/* this segment is the VM that is allocated by␊ |
360 | ␉␉␉␉ a fixed VM library, for overlap checking in␊ |
361 | ␉␉␉␉ the link editor */␊ |
362 | #define␉SG_NORELOC␉0x4␉/* this segment has nothing that was relocated␊ |
363 | ␉␉␉␉ in it and nothing relocated to it, that is␊ |
364 | ␉␉␉␉ it maybe safely replaced without relocation*/␊ |
365 | #define SG_PROTECTED_VERSION_1␉0x8 /* This segment is protected. If the␊ |
366 | ␉␉␉␉ segment starts at file offset 0, the␊ |
367 | ␉␉␉␉ first page of the segment is not␊ |
368 | ␉␉␉␉ protected. All other pages of the␊ |
369 | ␉␉␉␉ segment are protected. */␊ |
370 | ␊ |
371 | /*␊ |
372 | * A segment is made up of zero or more sections. Non-MH_OBJECT files have␊ |
373 | * all of their segments with the proper sections in each, and padded to the␊ |
374 | * specified segment alignment when produced by the link editor. The first␊ |
375 | * segment of a MH_EXECUTE and MH_FVMLIB format file contains the mach_header␊ |
376 | * and load commands of the object file before its first section. The zero␊ |
377 | * fill sections are always last in their segment (in all formats). This␊ |
378 | * allows the zeroed segment padding to be mapped into memory where zero fill␊ |
379 | * sections might be. The gigabyte zero fill sections, those with the section␊ |
380 | * type S_GB_ZEROFILL, can only be in a segment with sections of this type.␊ |
381 | * These segments are then placed after all other segments.␊ |
382 | *␊ |
383 | * The MH_OBJECT format has all of its sections in one segment for␊ |
384 | * compactness. There is no padding to a specified segment boundary and the␊ |
385 | * mach_header and load commands are not part of the segment.␊ |
386 | *␊ |
387 | * Sections with the same section name, sectname, going into the same segment,␊ |
388 | * segname, are combined by the link editor. The resulting section is aligned␊ |
389 | * to the maximum alignment of the combined sections and is the new section's␊ |
390 | * alignment. The combined sections are aligned to their original alignment in␊ |
391 | * the combined section. Any padded bytes to get the specified alignment are␊ |
392 | * zeroed.␊ |
393 | *␊ |
394 | * The format of the relocation entries referenced by the reloff and nreloc␊ |
395 | * fields of the section structure for mach object files is described in the␊ |
396 | * header file <reloc.h>.␊ |
397 | */␊ |
398 | struct section { /* for 32-bit architectures */␊ |
399 | ␉char␉␉sectname[16];␉/* name of this section */␊ |
400 | ␉char␉␉segname[16];␉/* segment this section goes in */␊ |
401 | ␉uint32_t␉addr;␉␉/* memory address of this section */␊ |
402 | ␉uint32_t␉size;␉␉/* size in bytes of this section */␊ |
403 | ␉uint32_t␉offset;␉␉/* file offset of this section */␊ |
404 | ␉uint32_t␉align;␉␉/* section alignment (power of 2) */␊ |
405 | ␉uint32_t␉reloff;␉␉/* file offset of relocation entries */␊ |
406 | ␉uint32_t␉nreloc;␉␉/* number of relocation entries */␊ |
407 | ␉uint32_t␉flags;␉␉/* flags (section type and attributes)*/␊ |
408 | ␉uint32_t␉reserved1;␉/* reserved (for offset or index) */␊ |
409 | ␉uint32_t␉reserved2;␉/* reserved (for count or sizeof) */␊ |
410 | };␊ |
411 | ␊ |
412 | struct section_64 { /* for 64-bit architectures */␊ |
413 | ␉char␉␉sectname[16];␉/* name of this section */␊ |
414 | ␉char␉␉segname[16];␉/* segment this section goes in */␊ |
415 | ␉uint64_t␉addr;␉␉/* memory address of this section */␊ |
416 | ␉uint64_t␉size;␉␉/* size in bytes of this section */␊ |
417 | ␉uint32_t␉offset;␉␉/* file offset of this section */␊ |
418 | ␉uint32_t␉align;␉␉/* section alignment (power of 2) */␊ |
419 | ␉uint32_t␉reloff;␉␉/* file offset of relocation entries */␊ |
420 | ␉uint32_t␉nreloc;␉␉/* number of relocation entries */␊ |
421 | ␉uint32_t␉flags;␉␉/* flags (section type and attributes)*/␊ |
422 | ␉uint32_t␉reserved1;␉/* reserved (for offset or index) */␊ |
423 | ␉uint32_t␉reserved2;␉/* reserved (for count or sizeof) */␊ |
424 | ␉uint32_t␉reserved3;␉/* reserved */␊ |
425 | };␊ |
426 | ␊ |
427 | /*␊ |
428 | * The flags field of a section structure is separated into two parts a section␊ |
429 | * type and section attributes. The section types are mutually exclusive (it␊ |
430 | * can only have one type) but the section attributes are not (it may have more␊ |
431 | * than one attribute).␊ |
432 | */␊ |
433 | #define SECTION_TYPE␉␉ 0x000000ff␉/* 256 section types */␊ |
434 | #define SECTION_ATTRIBUTES␉ 0xffffff00␉/* 24 section attributes */␊ |
435 | ␊ |
436 | /* Constants for the type of a section */␊ |
437 | #define␉S_REGULAR␉␉0x0␉/* regular section */␊ |
438 | #define␉S_ZEROFILL␉␉0x1␉/* zero fill on demand section */␊ |
439 | #define␉S_CSTRING_LITERALS␉0x2␉/* section with only literal C strings*/␊ |
440 | #define␉S_4BYTE_LITERALS␉0x3␉/* section with only 4 byte literals */␊ |
441 | #define␉S_8BYTE_LITERALS␉0x4␉/* section with only 8 byte literals */␊ |
442 | #define␉S_LITERAL_POINTERS␉0x5␉/* section with only pointers to */␊ |
443 | ␉␉␉␉␉/* literals */␊ |
444 | /*␊ |
445 | * For the two types of symbol pointers sections and the symbol stubs section␊ |
446 | * they have indirect symbol table entries. For each of the entries in the␊ |
447 | * section the indirect symbol table entries, in corresponding order in the␊ |
448 | * indirect symbol table, start at the index stored in the reserved1 field␊ |
449 | * of the section structure. Since the indirect symbol table entries␊ |
450 | * correspond to the entries in the section the number of indirect symbol table␊ |
451 | * entries is inferred from the size of the section divided by the size of the␊ |
452 | * entries in the section. For symbol pointers sections the size of the entries␊ |
453 | * in the section is 4 bytes and for symbol stubs sections the byte size of the␊ |
454 | * stubs is stored in the reserved2 field of the section structure.␊ |
455 | */␊ |
456 | #define␉S_NON_LAZY_SYMBOL_POINTERS␉0x6␉/* section with only non-lazy␊ |
457 | ␉␉␉␉␉␉ symbol pointers */␊ |
458 | #define␉S_LAZY_SYMBOL_POINTERS␉␉0x7␉/* section with only lazy symbol␊ |
459 | ␉␉␉␉␉␉ pointers */␊ |
460 | #define␉S_SYMBOL_STUBS␉␉␉0x8␉/* section with only symbol␊ |
461 | ␉␉␉␉␉␉ stubs, byte size of stub in␊ |
462 | ␉␉␉␉␉␉ the reserved2 field */␊ |
463 | #define␉S_MOD_INIT_FUNC_POINTERS␉0x9␉/* section with only function␊ |
464 | ␉␉␉␉␉␉ pointers for initialization*/␊ |
465 | #define␉S_MOD_TERM_FUNC_POINTERS␉0xa␉/* section with only function␊ |
466 | ␉␉␉␉␉␉ pointers for termination */␊ |
467 | #define␉S_COALESCED␉␉␉0xb␉/* section contains symbols that␊ |
468 | ␉␉␉␉␉␉ are to be coalesced */␊ |
469 | #define␉S_GB_ZEROFILL␉␉␉0xc␉/* zero fill on demand section␊ |
470 | ␉␉␉␉␉␉ (that can be larger than 4␊ |
471 | ␉␉␉␉␉␉ gigabytes) */␊ |
472 | #define␉S_INTERPOSING␉␉␉0xd␉/* section with only pairs of␊ |
473 | ␉␉␉␉␉␉ function pointers for␊ |
474 | ␉␉␉␉␉␉ interposing */␊ |
475 | #define␉S_16BYTE_LITERALS␉␉0xe␉/* section with only 16 byte␊ |
476 | ␉␉␉␉␉␉ literals */␊ |
477 | #define␉S_DTRACE_DOF␉␉␉0xf␉/* section contains ␊ |
478 | ␉␉␉␉␉␉ DTrace Object Format */␊ |
479 | #define␉S_LAZY_DYLIB_SYMBOL_POINTERS␉0x10␉/* section with only lazy␊ |
480 | ␉␉␉␉␉␉ symbol pointers to lazy␊ |
481 | ␉␉␉␉␉␉ loaded dylibs */␊ |
482 | /*␊ |
483 | * Section types to support thread local variables␊ |
484 | */␊ |
485 | #define S_THREAD_LOCAL_REGULAR 0x11 /* template of initial ␊ |
486 | ␉␉␉␉␉␉␉ values for TLVs */␊ |
487 | #define S_THREAD_LOCAL_ZEROFILL 0x12 /* template of initial ␊ |
488 | ␉␉␉␉␉␉␉ values for TLVs */␊ |
489 | #define S_THREAD_LOCAL_VARIABLES 0x13 /* TLV descriptors */␊ |
490 | #define S_THREAD_LOCAL_VARIABLE_POINTERS 0x14 /* pointers to TLV ␊ |
491 | descriptors */␊ |
492 | #define S_THREAD_LOCAL_INIT_FUNCTION_POINTERS 0x15 /* functions to call␊ |
493 | ␉␉␉␉␉␉␉ to initialize TLV␊ |
494 | ␉␉␉␉␉␉␉ values */␊ |
495 | ␊ |
496 | /*␊ |
497 | * Constants for the section attributes part of the flags field of a section␊ |
498 | * structure.␊ |
499 | */␊ |
500 | #define SECTION_ATTRIBUTES_USR␉ 0xff000000␉/* User setable attributes */␊ |
501 | #define S_ATTR_PURE_INSTRUCTIONS 0x80000000␉/* section contains only true␊ |
502 | ␉␉␉␉␉␉ machine instructions */␊ |
503 | #define S_ATTR_NO_TOC ␉␉ 0x40000000␉/* section contains coalesced␊ |
504 | ␉␉␉␉␉␉ symbols that are not to be␊ |
505 | ␉␉␉␉␉␉ in a ranlib table of␊ |
506 | ␉␉␉␉␉␉ contents */␊ |
507 | #define S_ATTR_STRIP_STATIC_SYMS 0x20000000␉/* ok to strip static symbols␊ |
508 | ␉␉␉␉␉␉ in this section in files␊ |
509 | ␉␉␉␉␉␉ with the MH_DYLDLINK flag */␊ |
510 | #define S_ATTR_NO_DEAD_STRIP␉ 0x10000000␉/* no dead stripping */␊ |
511 | #define S_ATTR_LIVE_SUPPORT␉ 0x08000000␉/* blocks are live if they␊ |
512 | ␉␉␉␉␉␉ reference live blocks */␊ |
513 | #define S_ATTR_SELF_MODIFYING_CODE 0x04000000␉/* Used with i386 code stubs␊ |
514 | ␉␉␉␉␉␉ written on by dyld */␊ |
515 | /*␊ |
516 | * If a segment contains any sections marked with S_ATTR_DEBUG then all␊ |
517 | * sections in that segment must have this attribute. No section other than␊ |
518 | * a section marked with this attribute may reference the contents of this␊ |
519 | * section. A section with this attribute may contain no symbols and must have␊ |
520 | * a section type S_REGULAR. The static linker will not copy section contents␊ |
521 | * from sections with this attribute into its output file. These sections␊ |
522 | * generally contain DWARF debugging info.␊ |
523 | */ ␊ |
524 | #define␉S_ATTR_DEBUG␉␉ 0x02000000␉/* a debug section */␊ |
525 | #define SECTION_ATTRIBUTES_SYS␉ 0x00ffff00␉/* system setable attributes */␊ |
526 | #define S_ATTR_SOME_INSTRUCTIONS 0x00000400␉/* section contains some␊ |
527 | ␉␉␉␉␉␉ machine instructions */␊ |
528 | #define S_ATTR_EXT_RELOC␉ 0x00000200␉/* section has external␊ |
529 | ␉␉␉␉␉␉ relocation entries */␊ |
530 | #define S_ATTR_LOC_RELOC␉ 0x00000100␉/* section has local␊ |
531 | ␉␉␉␉␉␉ relocation entries */␊ |
532 | ␊ |
533 | ␊ |
534 | /*␊ |
535 | * The names of segments and sections in them are mostly meaningless to the␊ |
536 | * link-editor. But there are few things to support traditional UNIX␊ |
537 | * executables that require the link-editor and assembler to use some names␊ |
538 | * agreed upon by convention.␊ |
539 | *␊ |
540 | * The initial protection of the "__TEXT" segment has write protection turned␊ |
541 | * off (not writeable).␊ |
542 | *␊ |
543 | * The link-editor will allocate common symbols at the end of the "__common"␊ |
544 | * section in the "__DATA" segment. It will create the section and segment␊ |
545 | * if needed.␊ |
546 | */␊ |
547 | ␊ |
548 | /* The currently known segment names and the section names in those segments */␊ |
549 | ␊ |
550 | #define␉SEG_PAGEZERO␉"__PAGEZERO"␉/* the pagezero segment which has no */␊ |
551 | ␉␉␉␉␉/* protections and catches NULL */␊ |
552 | ␉␉␉␉␉/* references for MH_EXECUTE files */␊ |
553 | ␊ |
554 | ␊ |
555 | #define␉SEG_TEXT␉"__TEXT"␉/* the tradition UNIX text segment */␊ |
556 | #define␉SECT_TEXT␉"__text"␉/* the real text part of the text */␊ |
557 | ␉␉␉␉␉/* section no headers, and no padding */␊ |
558 | #define SECT_FVMLIB_INIT0 "__fvmlib_init0"␉/* the fvmlib initialization */␊ |
559 | ␉␉␉␉␉␉/* section */␊ |
560 | #define SECT_FVMLIB_INIT1 "__fvmlib_init1"␉/* the section following the */␊ |
561 | ␉␉␉␉␉ /* fvmlib initialization */␊ |
562 | ␉␉␉␉␉␉/* section */␊ |
563 | ␊ |
564 | #define␉SEG_DATA␉"__DATA"␉/* the tradition UNIX data segment */␊ |
565 | #define␉SECT_DATA␉"__data"␉/* the real initialized data section */␊ |
566 | ␉␉␉␉␉/* no padding, no bss overlap */␊ |
567 | #define␉SECT_BSS␉"__bss"␉␉/* the real uninitialized data section*/␊ |
568 | ␉␉␉␉␉/* no padding */␊ |
569 | #define SECT_COMMON␉"__common"␉/* the section common symbols are */␊ |
570 | ␉␉␉␉␉/* allocated in by the link editor */␊ |
571 | ␊ |
572 | #define␉SEG_OBJC␉"__OBJC"␉/* objective-C runtime segment */␊ |
573 | #define SECT_OBJC_SYMBOLS "__symbol_table"␉/* symbol table */␊ |
574 | #define SECT_OBJC_MODULES "__module_info"␉/* module information */␊ |
575 | #define SECT_OBJC_STRINGS "__selector_strs"␉/* string table */␊ |
576 | #define SECT_OBJC_REFS "__selector_refs"␉/* string table */␊ |
577 | ␊ |
578 | #define␉SEG_ICON␉ "__ICON"␉/* the icon segment */␊ |
579 | #define␉SECT_ICON_HEADER "__header"␉/* the icon headers */␊ |
580 | #define␉SECT_ICON_TIFF "__tiff"␉/* the icons in tiff format */␊ |
581 | ␊ |
582 | #define␉SEG_LINKEDIT␉"__LINKEDIT"␉/* the segment containing all structs */␊ |
583 | ␉␉␉␉␉/* created and maintained by the link */␊ |
584 | ␉␉␉␉␉/* editor. Created with -seglinkedit */␊ |
585 | ␉␉␉␉␉/* option to ld(1) for MH_EXECUTE and */␊ |
586 | ␉␉␉␉␉/* FVMLIB file types only */␊ |
587 | ␊ |
588 | #define SEG_UNIXSTACK␉"__UNIXSTACK"␉/* the unix stack segment */␊ |
589 | ␊ |
590 | #define SEG_IMPORT␉"__IMPORT"␉/* the segment for the self (dyld) */␊ |
591 | ␉␉␉␉␉/* modifing code stubs that has read, */␊ |
592 | ␉␉␉␉␉/* write and execute permissions */␊ |
593 | ␊ |
594 | /*␊ |
595 | * Fixed virtual memory shared libraries are identified by two things. The␊ |
596 | * target pathname (the name of the library as found for execution), and the␊ |
597 | * minor version number. The address of where the headers are loaded is in␊ |
598 | * header_addr. (THIS IS OBSOLETE and no longer supported).␊ |
599 | */␊ |
600 | struct fvmlib {␊ |
601 | ␉union lc_str␉name;␉␉/* library's target pathname */␊ |
602 | ␉uint32_t␉minor_version;␉/* library's minor version number */␊ |
603 | ␉uint32_t␉header_addr;␉/* library's header address */␊ |
604 | };␊ |
605 | ␊ |
606 | /*␊ |
607 | * A fixed virtual shared library (filetype == MH_FVMLIB in the mach header)␊ |
608 | * contains a fvmlib_command (cmd == LC_IDFVMLIB) to identify the library.␊ |
609 | * An object that uses a fixed virtual shared library also contains a␊ |
610 | * fvmlib_command (cmd == LC_LOADFVMLIB) for each library it uses.␊ |
611 | * (THIS IS OBSOLETE and no longer supported).␊ |
612 | */␊ |
613 | struct fvmlib_command {␊ |
614 | ␉uint32_t␉cmd;␉␉/* LC_IDFVMLIB or LC_LOADFVMLIB */␊ |
615 | ␉uint32_t␉cmdsize;␉/* includes pathname string */␊ |
616 | ␉struct fvmlib␉fvmlib;␉␉/* the library identification */␊ |
617 | };␊ |
618 | ␊ |
619 | /*␊ |
620 | * Dynamicly linked shared libraries are identified by two things. The␊ |
621 | * pathname (the name of the library as found for execution), and the␊ |
622 | * compatibility version number. The pathname must match and the compatibility␊ |
623 | * number in the user of the library must be greater than or equal to the␊ |
624 | * library being used. The time stamp is used to record the time a library was␊ |
625 | * built and copied into user so it can be use to determined if the library used␊ |
626 | * at runtime is exactly the same as used to built the program.␊ |
627 | */␊ |
628 | struct dylib {␊ |
629 | union lc_str name;␉␉␉/* library's path name */␊ |
630 | uint32_t timestamp;␉␉␉/* library's build time stamp */␊ |
631 | uint32_t current_version;␉␉/* library's current version number */␊ |
632 | uint32_t compatibility_version;␉/* library's compatibility vers number*/␊ |
633 | };␊ |
634 | ␊ |
635 | /*␊ |
636 | * A dynamically linked shared library (filetype == MH_DYLIB in the mach header)␊ |
637 | * contains a dylib_command (cmd == LC_ID_DYLIB) to identify the library.␊ |
638 | * An object that uses a dynamically linked shared library also contains a␊ |
639 | * dylib_command (cmd == LC_LOAD_DYLIB, LC_LOAD_WEAK_DYLIB, or␊ |
640 | * LC_REEXPORT_DYLIB) for each library it uses.␊ |
641 | */␊ |
642 | struct dylib_command {␊ |
643 | ␉uint32_t␉cmd;␉␉/* LC_ID_DYLIB, LC_LOAD_{,WEAK_}DYLIB,␊ |
644 | ␉␉␉␉␉ LC_REEXPORT_DYLIB */␊ |
645 | ␉uint32_t␉cmdsize;␉/* includes pathname string */␊ |
646 | ␉struct dylib␉dylib;␉␉/* the library identification */␊ |
647 | };␊ |
648 | ␊ |
649 | /*␊ |
650 | * A dynamically linked shared library may be a subframework of an umbrella␊ |
651 | * framework. If so it will be linked with "-umbrella umbrella_name" where␊ |
652 | * Where "umbrella_name" is the name of the umbrella framework. A subframework␊ |
653 | * can only be linked against by its umbrella framework or other subframeworks␊ |
654 | * that are part of the same umbrella framework. Otherwise the static link␊ |
655 | * editor produces an error and states to link against the umbrella framework.␊ |
656 | * The name of the umbrella framework for subframeworks is recorded in the␊ |
657 | * following structure.␊ |
658 | */␊ |
659 | struct sub_framework_command {␊ |
660 | ␉uint32_t␉cmd;␉␉/* LC_SUB_FRAMEWORK */␊ |
661 | ␉uint32_t␉cmdsize;␉/* includes umbrella string */␊ |
662 | ␉union lc_str ␉umbrella;␉/* the umbrella framework name */␊ |
663 | };␊ |
664 | ␊ |
665 | /*␊ |
666 | * For dynamically linked shared libraries that are subframework of an umbrella␊ |
667 | * framework they can allow clients other than the umbrella framework or other␊ |
668 | * subframeworks in the same umbrella framework. To do this the subframework␊ |
669 | * is built with "-allowable_client client_name" and an LC_SUB_CLIENT load␊ |
670 | * command is created for each -allowable_client flag. The client_name is␊ |
671 | * usually a framework name. It can also be a name used for bundles clients␊ |
672 | * where the bundle is built with "-client_name client_name".␊ |
673 | */␊ |
674 | struct sub_client_command {␊ |
675 | ␉uint32_t␉cmd;␉␉/* LC_SUB_CLIENT */␊ |
676 | ␉uint32_t␉cmdsize;␉/* includes client string */␊ |
677 | ␉union lc_str ␉client;␉␉/* the client name */␊ |
678 | };␊ |
679 | ␊ |
680 | /*␊ |
681 | * A dynamically linked shared library may be a sub_umbrella of an umbrella␊ |
682 | * framework. If so it will be linked with "-sub_umbrella umbrella_name" where␊ |
683 | * Where "umbrella_name" is the name of the sub_umbrella framework. When␊ |
684 | * staticly linking when -twolevel_namespace is in effect a twolevel namespace ␊ |
685 | * umbrella framework will only cause its subframeworks and those frameworks␊ |
686 | * listed as sub_umbrella frameworks to be implicited linked in. Any other␊ |
687 | * dependent dynamic libraries will not be linked it when -twolevel_namespace␊ |
688 | * is in effect. The primary library recorded by the static linker when␊ |
689 | * resolving a symbol in these libraries will be the umbrella framework.␊ |
690 | * Zero or more sub_umbrella frameworks may be use by an umbrella framework.␊ |
691 | * The name of a sub_umbrella framework is recorded in the following structure.␊ |
692 | */␊ |
693 | struct sub_umbrella_command {␊ |
694 | ␉uint32_t␉cmd;␉␉/* LC_SUB_UMBRELLA */␊ |
695 | ␉uint32_t␉cmdsize;␉/* includes sub_umbrella string */␊ |
696 | ␉union lc_str ␉sub_umbrella;␉/* the sub_umbrella framework name */␊ |
697 | };␊ |
698 | ␊ |
699 | /*␊ |
700 | * A dynamically linked shared library may be a sub_library of another shared␊ |
701 | * library. If so it will be linked with "-sub_library library_name" where␊ |
702 | * Where "library_name" is the name of the sub_library shared library. When␊ |
703 | * staticly linking when -twolevel_namespace is in effect a twolevel namespace ␊ |
704 | * shared library will only cause its subframeworks and those frameworks␊ |
705 | * listed as sub_umbrella frameworks and libraries listed as sub_libraries to␊ |
706 | * be implicited linked in. Any other dependent dynamic libraries will not be␊ |
707 | * linked it when -twolevel_namespace is in effect. The primary library␊ |
708 | * recorded by the static linker when resolving a symbol in these libraries␊ |
709 | * will be the umbrella framework (or dynamic library). Zero or more sub_library␊ |
710 | * shared libraries may be use by an umbrella framework or (or dynamic library).␊ |
711 | * The name of a sub_library framework is recorded in the following structure.␊ |
712 | * For example /usr/lib/libobjc_profile.A.dylib would be recorded as "libobjc".␊ |
713 | */␊ |
714 | struct sub_library_command {␊ |
715 | ␉uint32_t␉cmd;␉␉/* LC_SUB_LIBRARY */␊ |
716 | ␉uint32_t␉cmdsize;␉/* includes sub_library string */␊ |
717 | ␉union lc_str ␉sub_library;␉/* the sub_library name */␊ |
718 | };␊ |
719 | ␊ |
720 | /*␊ |
721 | * A program (filetype == MH_EXECUTE) that is␊ |
722 | * prebound to its dynamic libraries has one of these for each library that␊ |
723 | * the static linker used in prebinding. It contains a bit vector for the␊ |
724 | * modules in the library. The bits indicate which modules are bound (1) and␊ |
725 | * which are not (0) from the library. The bit for module 0 is the low bit␊ |
726 | * of the first byte. So the bit for the Nth module is:␊ |
727 | * (linked_modules[N/8] >> N%8) & 1␊ |
728 | */␊ |
729 | struct prebound_dylib_command {␊ |
730 | ␉uint32_t␉cmd;␉␉/* LC_PREBOUND_DYLIB */␊ |
731 | ␉uint32_t␉cmdsize;␉/* includes strings */␊ |
732 | ␉union lc_str␉name;␉␉/* library's path name */␊ |
733 | ␉uint32_t␉nmodules;␉/* number of modules in library */␊ |
734 | ␉union lc_str␉linked_modules;␉/* bit vector of linked modules */␊ |
735 | };␊ |
736 | ␊ |
737 | /*␊ |
738 | * A program that uses a dynamic linker contains a dylinker_command to identify␊ |
739 | * the name of the dynamic linker (LC_LOAD_DYLINKER). And a dynamic linker␊ |
740 | * contains a dylinker_command to identify the dynamic linker (LC_ID_DYLINKER).␊ |
741 | * A file can have at most one of these.␊ |
742 | * This struct is also used for the LC_DYLD_ENVIRONMENT load command and␊ |
743 | * contains string for dyld to treat like environment variable.␊ |
744 | */␊ |
745 | struct dylinker_command {␊ |
746 | ␉uint32_t␉cmd;␉␉/* LC_ID_DYLINKER, LC_LOAD_DYLINKER or␊ |
747 | ␉␉␉␉␉ LC_DYLD_ENVIRONMENT */␊ |
748 | ␉uint32_t␉cmdsize;␉/* includes pathname string */␊ |
749 | ␉union lc_str name;␉␉/* dynamic linker's path name */␊ |
750 | };␊ |
751 | ␊ |
752 | /*␊ |
753 | * Thread commands contain machine-specific data structures suitable for␊ |
754 | * use in the thread state primitives. The machine specific data structures␊ |
755 | * follow the struct thread_command as follows.␊ |
756 | * Each flavor of machine specific data structure is preceded by an unsigned␊ |
757 | * long constant for the flavor of that data structure, an uint32_t␊ |
758 | * that is the count of longs of the size of the state data structure and then␊ |
759 | * the state data structure follows. This triple may be repeated for many␊ |
760 | * flavors. The constants for the flavors, counts and state data structure␊ |
761 | * definitions are expected to be in the header file <machine/thread_status.h>.␊ |
762 | * These machine specific data structures sizes must be multiples of␊ |
763 | * 4 bytes The cmdsize reflects the total size of the thread_command␊ |
764 | * and all of the sizes of the constants for the flavors, counts and state␊ |
765 | * data structures.␊ |
766 | *␊ |
767 | * For executable objects that are unix processes there will be one␊ |
768 | * thread_command (cmd == LC_UNIXTHREAD) created for it by the link-editor.␊ |
769 | * This is the same as a LC_THREAD, except that a stack is automatically␊ |
770 | * created (based on the shell's limit for the stack size). Command arguments␊ |
771 | * and environment variables are copied onto that stack.␊ |
772 | */␊ |
773 | struct thread_command {␊ |
774 | ␉uint32_t␉cmd;␉␉/* LC_THREAD or LC_UNIXTHREAD */␊ |
775 | ␉uint32_t␉cmdsize;␉/* total size of this command */␊ |
776 | ␉/* uint32_t flavor␉␉ flavor of thread state */␊ |
777 | ␉/* uint32_t count␉␉ count of longs in thread state */␊ |
778 | ␉/* struct XXX_thread_state state thread state for this flavor */␊ |
779 | ␉/* ... */␊ |
780 | };␊ |
781 | ␊ |
782 | /*␊ |
783 | * The routines command contains the address of the dynamic shared library ␊ |
784 | * initialization routine and an index into the module table for the module␊ |
785 | * that defines the routine. Before any modules are used from the library the␊ |
786 | * dynamic linker fully binds the module that defines the initialization routine␊ |
787 | * and then calls it. This gets called before any module initialization␊ |
788 | * routines (used for C++ static constructors) in the library.␊ |
789 | */␊ |
790 | struct routines_command { /* for 32-bit architectures */␊ |
791 | ␉uint32_t␉cmd;␉␉/* LC_ROUTINES */␊ |
792 | ␉uint32_t␉cmdsize;␉/* total size of this command */␊ |
793 | ␉uint32_t␉init_address;␉/* address of initialization routine */␊ |
794 | ␉uint32_t␉init_module;␉/* index into the module table that */␊ |
795 | ␉␉␉␉ /* the init routine is defined in */␊ |
796 | ␉uint32_t␉reserved1;␊ |
797 | ␉uint32_t␉reserved2;␊ |
798 | ␉uint32_t␉reserved3;␊ |
799 | ␉uint32_t␉reserved4;␊ |
800 | ␉uint32_t␉reserved5;␊ |
801 | ␉uint32_t␉reserved6;␊ |
802 | };␊ |
803 | ␊ |
804 | /*␊ |
805 | * The 64-bit routines command. Same use as above.␊ |
806 | */␊ |
807 | struct routines_command_64 { /* for 64-bit architectures */␊ |
808 | ␉uint32_t␉cmd;␉␉/* LC_ROUTINES_64 */␊ |
809 | ␉uint32_t␉cmdsize;␉/* total size of this command */␊ |
810 | ␉uint64_t␉init_address;␉/* address of initialization routine */␊ |
811 | ␉uint64_t␉init_module;␉/* index into the module table that */␊ |
812 | ␉␉␉␉␉/* the init routine is defined in */␊ |
813 | ␉uint64_t␉reserved1;␊ |
814 | ␉uint64_t␉reserved2;␊ |
815 | ␉uint64_t␉reserved3;␊ |
816 | ␉uint64_t␉reserved4;␊ |
817 | ␉uint64_t␉reserved5;␊ |
818 | ␉uint64_t␉reserved6;␊ |
819 | };␊ |
820 | ␊ |
821 | /*␊ |
822 | * The symtab_command contains the offsets and sizes of the link-edit 4.3BSD␊ |
823 | * "stab" style symbol table information as described in the header files␊ |
824 | * <nlist.h> and <stab.h>.␊ |
825 | */␊ |
826 | struct symtab_command {␊ |
827 | ␉uint32_t␉cmd;␉␉/* LC_SYMTAB */␊ |
828 | ␉uint32_t␉cmdsize;␉/* sizeof(struct symtab_command) */␊ |
829 | ␉uint32_t␉symoff;␉␉/* symbol table offset */␊ |
830 | ␉uint32_t␉nsyms;␉␉/* number of symbol table entries */␊ |
831 | ␉uint32_t␉stroff;␉␉/* string table offset */␊ |
832 | ␉uint32_t␉strsize;␉/* string table size in bytes */␊ |
833 | };␊ |
834 | ␊ |
835 | /*␊ |
836 | * This is the second set of the symbolic information which is used to support␊ |
837 | * the data structures for the dynamically link editor.␊ |
838 | *␊ |
839 | * The original set of symbolic information in the symtab_command which contains␊ |
840 | * the symbol and string tables must also be present when this load command is␊ |
841 | * present. When this load command is present the symbol table is organized␊ |
842 | * into three groups of symbols:␊ |
843 | *␉local symbols (static and debugging symbols) - grouped by module␊ |
844 | *␉defined external symbols - grouped by module (sorted by name if not lib)␊ |
845 | *␉undefined external symbols (sorted by name if MH_BINDATLOAD is not set,␊ |
846 | *␉ ␉␉␉ and in order the were seen by the static␊ |
847 | *␉␉␉␉ linker if MH_BINDATLOAD is set)␊ |
848 | * In this load command there are offsets and counts to each of the three groups␊ |
849 | * of symbols.␊ |
850 | *␊ |
851 | * This load command contains a the offsets and sizes of the following new␊ |
852 | * symbolic information tables:␊ |
853 | *␉table of contents␊ |
854 | *␉module table␊ |
855 | *␉reference symbol table␊ |
856 | *␉indirect symbol table␊ |
857 | * The first three tables above (the table of contents, module table and␊ |
858 | * reference symbol table) are only present if the file is a dynamically linked␊ |
859 | * shared library. For executable and object modules, which are files␊ |
860 | * containing only one module, the information that would be in these three␊ |
861 | * tables is determined as follows:␊ |
862 | * ␉table of contents - the defined external symbols are sorted by name␊ |
863 | *␉module table - the file contains only one module so everything in the␊ |
864 | *␉␉ file is part of the module.␊ |
865 | *␉reference symbol table - is the defined and undefined external symbols␊ |
866 | *␊ |
867 | * For dynamically linked shared library files this load command also contains␊ |
868 | * offsets and sizes to the pool of relocation entries for all sections␊ |
869 | * separated into two groups:␊ |
870 | *␉external relocation entries␊ |
871 | *␉local relocation entries␊ |
872 | * For executable and object modules the relocation entries continue to hang␊ |
873 | * off the section structures.␊ |
874 | */␊ |
875 | struct dysymtab_command {␊ |
876 | uint32_t cmd;␉/* LC_DYSYMTAB */␊ |
877 | uint32_t cmdsize;␉/* sizeof(struct dysymtab_command) */␊ |
878 | ␊ |
879 | /*␊ |
880 | * The symbols indicated by symoff and nsyms of the LC_SYMTAB load command␊ |
881 | * are grouped into the following three groups:␊ |
882 | * local symbols (further grouped by the module they are from)␊ |
883 | * defined external symbols (further grouped by the module they are from)␊ |
884 | * undefined symbols␊ |
885 | *␊ |
886 | * The local symbols are used only for debugging. The dynamic binding␊ |
887 | * process may have to use them to indicate to the debugger the local␊ |
888 | * symbols for a module that is being bound.␊ |
889 | *␊ |
890 | * The last two groups are used by the dynamic binding process to do the␊ |
891 | * binding (indirectly through the module table and the reference symbol␊ |
892 | * table when this is a dynamically linked shared library file).␊ |
893 | */␊ |
894 | uint32_t ilocalsym;␉/* index to local symbols */␊ |
895 | uint32_t nlocalsym;␉/* number of local symbols */␊ |
896 | ␊ |
897 | uint32_t iextdefsym;/* index to externally defined symbols */␊ |
898 | uint32_t nextdefsym;/* number of externally defined symbols */␊ |
899 | ␊ |
900 | uint32_t iundefsym;␉/* index to undefined symbols */␊ |
901 | uint32_t nundefsym;␉/* number of undefined symbols */␊ |
902 | ␊ |
903 | /*␊ |
904 | * For the for the dynamic binding process to find which module a symbol␊ |
905 | * is defined in the table of contents is used (analogous to the ranlib␊ |
906 | * structure in an archive) which maps defined external symbols to modules␊ |
907 | * they are defined in. This exists only in a dynamically linked shared␊ |
908 | * library file. For executable and object modules the defined external␊ |
909 | * symbols are sorted by name and is use as the table of contents.␊ |
910 | */␊ |
911 | uint32_t tocoff;␉/* file offset to table of contents */␊ |
912 | uint32_t ntoc;␉/* number of entries in table of contents */␊ |
913 | ␊ |
914 | /*␊ |
915 | * To support dynamic binding of "modules" (whole object files) the symbol␊ |
916 | * table must reflect the modules that the file was created from. This is␊ |
917 | * done by having a module table that has indexes and counts into the merged␊ |
918 | * tables for each module. The module structure that these two entries␊ |
919 | * refer to is described below. This exists only in a dynamically linked␊ |
920 | * shared library file. For executable and object modules the file only␊ |
921 | * contains one module so everything in the file belongs to the module.␊ |
922 | */␊ |
923 | uint32_t modtaboff;␉/* file offset to module table */␊ |
924 | uint32_t nmodtab;␉/* number of module table entries */␊ |
925 | ␊ |
926 | /*␊ |
927 | * To support dynamic module binding the module structure for each module␊ |
928 | * indicates the external references (defined and undefined) each module␊ |
929 | * makes. For each module there is an offset and a count into the␊ |
930 | * reference symbol table for the symbols that the module references.␊ |
931 | * This exists only in a dynamically linked shared library file. For␊ |
932 | * executable and object modules the defined external symbols and the␊ |
933 | * undefined external symbols indicates the external references.␊ |
934 | */␊ |
935 | uint32_t extrefsymoff;␉/* offset to referenced symbol table */␊ |
936 | uint32_t nextrefsyms;␉/* number of referenced symbol table entries */␊ |
937 | ␊ |
938 | /*␊ |
939 | * The sections that contain "symbol pointers" and "routine stubs" have␊ |
940 | * indexes and (implied counts based on the size of the section and fixed␊ |
941 | * size of the entry) into the "indirect symbol" table for each pointer␊ |
942 | * and stub. For every section of these two types the index into the␊ |
943 | * indirect symbol table is stored in the section header in the field␊ |
944 | * reserved1. An indirect symbol table entry is simply a 32bit index into␊ |
945 | * the symbol table to the symbol that the pointer or stub is referring to.␊ |
946 | * The indirect symbol table is ordered to match the entries in the section.␊ |
947 | */␊ |
948 | uint32_t indirectsymoff; /* file offset to the indirect symbol table */␊ |
949 | uint32_t nindirectsyms; /* number of indirect symbol table entries */␊ |
950 | ␊ |
951 | /*␊ |
952 | * To support relocating an individual module in a library file quickly the␊ |
953 | * external relocation entries for each module in the library need to be␊ |
954 | * accessed efficiently. Since the relocation entries can't be accessed␊ |
955 | * through the section headers for a library file they are separated into␊ |
956 | * groups of local and external entries further grouped by module. In this␊ |
957 | * case the presents of this load command who's extreloff, nextrel,␊ |
958 | * locreloff and nlocrel fields are non-zero indicates that the relocation␊ |
959 | * entries of non-merged sections are not referenced through the section␊ |
960 | * structures (and the reloff and nreloc fields in the section headers are␊ |
961 | * set to zero).␊ |
962 | *␊ |
963 | * Since the relocation entries are not accessed through the section headers␊ |
964 | * this requires the r_address field to be something other than a section␊ |
965 | * offset to identify the item to be relocated. In this case r_address is␊ |
966 | * set to the offset from the vmaddr of the first LC_SEGMENT command.␊ |
967 | * For MH_SPLIT_SEGS images r_address is set to the the offset from the␊ |
968 | * vmaddr of the first read-write LC_SEGMENT command.␊ |
969 | *␊ |
970 | * The relocation entries are grouped by module and the module table␊ |
971 | * entries have indexes and counts into them for the group of external␊ |
972 | * relocation entries for that the module.␊ |
973 | *␊ |
974 | * For sections that are merged across modules there must not be any␊ |
975 | * remaining external relocation entries for them (for merged sections␊ |
976 | * remaining relocation entries must be local).␊ |
977 | */␊ |
978 | uint32_t extreloff;␉/* offset to external relocation entries */␊ |
979 | uint32_t nextrel;␉/* number of external relocation entries */␊ |
980 | ␊ |
981 | /*␊ |
982 | * All the local relocation entries are grouped together (they are not␊ |
983 | * grouped by their module since they are only used if the object is moved␊ |
984 | * from it staticly link edited address).␊ |
985 | */␊ |
986 | uint32_t locreloff;␉/* offset to local relocation entries */␊ |
987 | uint32_t nlocrel;␉/* number of local relocation entries */␊ |
988 | ␊ |
989 | };␉␊ |
990 | ␊ |
991 | /*␊ |
992 | * An indirect symbol table entry is simply a 32bit index into the symbol table ␊ |
993 | * to the symbol that the pointer or stub is refering to. Unless it is for a␊ |
994 | * non-lazy symbol pointer section for a defined symbol which strip(1) as ␊ |
995 | * removed. In which case it has the value INDIRECT_SYMBOL_LOCAL. If the␊ |
996 | * symbol was also absolute INDIRECT_SYMBOL_ABS is or'ed with that.␊ |
997 | */␊ |
998 | #define INDIRECT_SYMBOL_LOCAL␉0x80000000␊ |
999 | #define INDIRECT_SYMBOL_ABS␉0x40000000␊ |
1000 | ␊ |
1001 | ␊ |
1002 | /* a table of contents entry */␊ |
1003 | struct dylib_table_of_contents {␊ |
1004 | uint32_t symbol_index;␉/* the defined external symbol␊ |
1005 | ␉␉␉␉ (index into the symbol table) */␊ |
1006 | uint32_t module_index;␉/* index into the module table this symbol␊ |
1007 | ␉␉␉␉ is defined in */␊ |
1008 | };␉␊ |
1009 | ␊ |
1010 | /* a module table entry */␊ |
1011 | struct dylib_module {␊ |
1012 | uint32_t module_name;␉/* the module name (index into string table) */␊ |
1013 | ␊ |
1014 | uint32_t iextdefsym;␉/* index into externally defined symbols */␊ |
1015 | uint32_t nextdefsym;␉/* number of externally defined symbols */␊ |
1016 | uint32_t irefsym;␉␉/* index into reference symbol table */␊ |
1017 | uint32_t nrefsym;␉␉/* number of reference symbol table entries */␊ |
1018 | uint32_t ilocalsym;␉␉/* index into symbols for local symbols */␊ |
1019 | uint32_t nlocalsym;␉␉/* number of local symbols */␊ |
1020 | ␊ |
1021 | uint32_t iextrel;␉␉/* index into external relocation entries */␊ |
1022 | uint32_t nextrel;␉␉/* number of external relocation entries */␊ |
1023 | ␊ |
1024 | uint32_t iinit_iterm;␉/* low 16 bits are the index into the init␊ |
1025 | ␉␉␉␉ section, high 16 bits are the index into␊ |
1026 | ␉␉␉ the term section */␊ |
1027 | uint32_t ninit_nterm;␉/* low 16 bits are the number of init section␊ |
1028 | ␉␉␉␉ entries, high 16 bits are the number of␊ |
1029 | ␉␉␉␉ term section entries */␊ |
1030 | ␊ |
1031 | uint32_t␉␉␉/* for this module address of the start of */␊ |
1032 | ␉objc_module_info_addr; /* the (__OBJC,__module_info) section */␊ |
1033 | uint32_t␉␉␉/* for this module size of */␊ |
1034 | ␉objc_module_info_size;␉/* the (__OBJC,__module_info) section */␊ |
1035 | };␉␊ |
1036 | ␊ |
1037 | /* a 64-bit module table entry */␊ |
1038 | struct dylib_module_64 {␊ |
1039 | uint32_t module_name;␉/* the module name (index into string table) */␊ |
1040 | ␊ |
1041 | uint32_t iextdefsym;␉/* index into externally defined symbols */␊ |
1042 | uint32_t nextdefsym;␉/* number of externally defined symbols */␊ |
1043 | uint32_t irefsym;␉␉/* index into reference symbol table */␊ |
1044 | uint32_t nrefsym;␉␉/* number of reference symbol table entries */␊ |
1045 | uint32_t ilocalsym;␉␉/* index into symbols for local symbols */␊ |
1046 | uint32_t nlocalsym;␉␉/* number of local symbols */␊ |
1047 | ␊ |
1048 | uint32_t iextrel;␉␉/* index into external relocation entries */␊ |
1049 | uint32_t nextrel;␉␉/* number of external relocation entries */␊ |
1050 | ␊ |
1051 | uint32_t iinit_iterm;␉/* low 16 bits are the index into the init␊ |
1052 | ␉␉␉␉ section, high 16 bits are the index into␊ |
1053 | ␉␉␉␉ the term section */␊ |
1054 | uint32_t ninit_nterm; /* low 16 bits are the number of init section␊ |
1055 | ␉␉␉␉ entries, high 16 bits are the number of␊ |
1056 | ␉␉␉␉ term section entries */␊ |
1057 | ␊ |
1058 | uint32_t␉␉␉/* for this module size of */␊ |
1059 | objc_module_info_size;␉/* the (__OBJC,__module_info) section */␊ |
1060 | uint64_t␉␉␉/* for this module address of the start of */␊ |
1061 | objc_module_info_addr;␉/* the (__OBJC,__module_info) section */␊ |
1062 | };␊ |
1063 | ␊ |
1064 | /* ␊ |
1065 | * The entries in the reference symbol table are used when loading the module␊ |
1066 | * (both by the static and dynamic link editors) and if the module is unloaded␊ |
1067 | * or replaced. Therefore all external symbols (defined and undefined) are␊ |
1068 | * listed in the module's reference table. The flags describe the type of␊ |
1069 | * reference that is being made. The constants for the flags are defined in␊ |
1070 | * <mach-o/nlist.h> as they are also used for symbol table entries.␊ |
1071 | */␊ |
1072 | struct dylib_reference {␊ |
1073 | uint32_t isym:24,␉␉/* index into the symbol table */␊ |
1074 | ␉␉ flags:8;␉/* flags to indicate the type of reference */␊ |
1075 | };␊ |
1076 | ␊ |
1077 | /*␊ |
1078 | * The twolevel_hints_command contains the offset and number of hints in the␊ |
1079 | * two-level namespace lookup hints table.␊ |
1080 | */␊ |
1081 | struct twolevel_hints_command {␊ |
1082 | uint32_t cmd;␉/* LC_TWOLEVEL_HINTS */␊ |
1083 | uint32_t cmdsize;␉/* sizeof(struct twolevel_hints_command) */␊ |
1084 | uint32_t offset;␉/* offset to the hint table */␊ |
1085 | uint32_t nhints;␉/* number of hints in the hint table */␊ |
1086 | };␊ |
1087 | ␊ |
1088 | /*␊ |
1089 | * The entries in the two-level namespace lookup hints table are twolevel_hint␊ |
1090 | * structs. These provide hints to the dynamic link editor where to start␊ |
1091 | * looking for an undefined symbol in a two-level namespace image. The␊ |
1092 | * isub_image field is an index into the sub-images (sub-frameworks and␊ |
1093 | * sub-umbrellas list) that made up the two-level image that the undefined␊ |
1094 | * symbol was found in when it was built by the static link editor. If␊ |
1095 | * isub-image is 0 the the symbol is expected to be defined in library and not␊ |
1096 | * in the sub-images. If isub-image is non-zero it is an index into the array␊ |
1097 | * of sub-images for the umbrella with the first index in the sub-images being␊ |
1098 | * 1. The array of sub-images is the ordered list of sub-images of the umbrella␊ |
1099 | * that would be searched for a symbol that has the umbrella recorded as its␊ |
1100 | * primary library. The table of contents index is an index into the␊ |
1101 | * library's table of contents. This is used as the starting point of the␊ |
1102 | * binary search or a directed linear search.␊ |
1103 | */␊ |
1104 | struct twolevel_hint {␊ |
1105 | uint32_t ␊ |
1106 | ␉isub_image:8,␉/* index into the sub images */␊ |
1107 | ␉itoc:24;␉/* index into the table of contents */␊ |
1108 | };␊ |
1109 | ␊ |
1110 | /*␊ |
1111 | * The prebind_cksum_command contains the value of the original check sum for␊ |
1112 | * prebound files or zero. When a prebound file is first created or modified␊ |
1113 | * for other than updating its prebinding information the value of the check sum␊ |
1114 | * is set to zero. When the file has it prebinding re-done and if the value of␊ |
1115 | * the check sum is zero the original check sum is calculated and stored in␊ |
1116 | * cksum field of this load command in the output file. If when the prebinding␊ |
1117 | * is re-done and the cksum field is non-zero it is left unchanged from the␊ |
1118 | * input file.␊ |
1119 | */␊ |
1120 | struct prebind_cksum_command {␊ |
1121 | uint32_t cmd;␉/* LC_PREBIND_CKSUM */␊ |
1122 | uint32_t cmdsize;␉/* sizeof(struct prebind_cksum_command) */␊ |
1123 | uint32_t cksum;␉/* the check sum or zero */␊ |
1124 | };␊ |
1125 | ␊ |
1126 | /*␊ |
1127 | * The uuid load command contains a single 128-bit unique random number that␊ |
1128 | * identifies an object produced by the static link editor.␊ |
1129 | */␊ |
1130 | struct uuid_command {␊ |
1131 | uint32_t␉cmd;␉␉/* LC_UUID */␊ |
1132 | uint32_t␉cmdsize;␉/* sizeof(struct uuid_command) */␊ |
1133 | uint8_t␉uuid[16];␉/* the 128-bit uuid */␊ |
1134 | };␊ |
1135 | ␊ |
1136 | /*␊ |
1137 | * The rpath_command contains a path which at runtime should be added to␊ |
1138 | * the current run path used to find @rpath prefixed dylibs.␊ |
1139 | */␊ |
1140 | struct rpath_command {␊ |
1141 | uint32_t␉ cmd;␉␉/* LC_RPATH */␊ |
1142 | uint32_t␉ cmdsize;␉/* includes string */␊ |
1143 | union lc_str path;␉␉/* path to add to run path */␊ |
1144 | };␊ |
1145 | ␊ |
1146 | /*␊ |
1147 | * The linkedit_data_command contains the offsets and sizes of a blob␊ |
1148 | * of data in the __LINKEDIT segment. ␊ |
1149 | */␊ |
1150 | struct linkedit_data_command {␊ |
1151 | uint32_t␉cmd;␉␉/* LC_CODE_SIGNATURE, LC_SEGMENT_SPLIT_INFO,␊ |
1152 | or LC_FUNCTION_STARTS */␊ |
1153 | uint32_t␉cmdsize;␉/* sizeof(struct linkedit_data_command) */␊ |
1154 | uint32_t␉dataoff;␉/* file offset of data in __LINKEDIT segment */␊ |
1155 | uint32_t␉datasize;␉/* file size of data in __LINKEDIT segment */␊ |
1156 | };␊ |
1157 | ␊ |
1158 | /*␊ |
1159 | * The encryption_info_command contains the file offset and size of an␊ |
1160 | * of an encrypted segment.␊ |
1161 | */␊ |
1162 | struct encryption_info_command {␊ |
1163 | uint32_t␉cmd;␉␉/* LC_ENCRYPTION_INFO */␊ |
1164 | uint32_t␉cmdsize;␉/* sizeof(struct encryption_info_command) */␊ |
1165 | uint32_t␉cryptoff;␉/* file offset of encrypted range */␊ |
1166 | uint32_t␉cryptsize;␉/* file size of encrypted range */␊ |
1167 | uint32_t␉cryptid;␉/* which enryption system,␊ |
1168 | ␉␉␉␉ 0 means not-encrypted yet */␊ |
1169 | };␊ |
1170 | ␊ |
1171 | /*␊ |
1172 | * The version_min_command contains the min OS version on which this ␊ |
1173 | * binary was built to run.␊ |
1174 | */␊ |
1175 | struct version_min_command {␊ |
1176 | uint32_t␉cmd;␉␉/* LC_VERSION_MIN_MACOSX or␊ |
1177 | ␉␉␉␉ LC_VERSION_MIN_IPHONEOS */␊ |
1178 | uint32_t␉cmdsize;␉/* sizeof(struct min_version_command) */␊ |
1179 | uint32_t␉version;␉/* X.Y.Z is encoded in nibbles xxxx.yy.zz */␊ |
1180 | uint32_t␉reserved;␉/* zero */␊ |
1181 | };␊ |
1182 | ␊ |
1183 | /*␊ |
1184 | * The dyld_info_command contains the file offsets and sizes of ␊ |
1185 | * the new compressed form of the information dyld needs to ␊ |
1186 | * load the image. This information is used by dyld on Mac OS X␊ |
1187 | * 10.6 and later. All information pointed to by this command␊ |
1188 | * is encoded using byte streams, so no endian swapping is needed␊ |
1189 | * to interpret it. ␊ |
1190 | */␊ |
1191 | struct dyld_info_command {␊ |
1192 | uint32_t cmd;␉␉/* LC_DYLD_INFO or LC_DYLD_INFO_ONLY */␊ |
1193 | uint32_t cmdsize;␉␉/* sizeof(struct dyld_info_command) */␊ |
1194 | ␊ |
1195 | /*␊ |
1196 | * Dyld rebases an image whenever dyld loads it at an address different␊ |
1197 | * from its preferred address. The rebase information is a stream␊ |
1198 | * of byte sized opcodes whose symbolic names start with REBASE_OPCODE_.␊ |
1199 | * Conceptually the rebase information is a table of tuples:␊ |
1200 | * <seg-index, seg-offset, type>␊ |
1201 | * The opcodes are a compressed way to encode the table by only␊ |
1202 | * encoding when a column changes. In addition simple patterns␊ |
1203 | * like "every n'th offset for m times" can be encoded in a few␊ |
1204 | * bytes.␊ |
1205 | */␊ |
1206 | uint32_t rebase_off;␉/* file offset to rebase info */␊ |
1207 | uint32_t rebase_size;␉/* size of rebase info */␊ |
1208 | ␊ |
1209 | /*␊ |
1210 | * Dyld binds an image during the loading process, if the image␊ |
1211 | * requires any pointers to be initialized to symbols in other images. ␊ |
1212 | * The bind information is a stream of byte sized ␊ |
1213 | * opcodes whose symbolic names start with BIND_OPCODE_.␊ |
1214 | * Conceptually the bind information is a table of tuples:␊ |
1215 | * <seg-index, seg-offset, type, symbol-library-ordinal, symbol-name, addend>␊ |
1216 | * The opcodes are a compressed way to encode the table by only␊ |
1217 | * encoding when a column changes. In addition simple patterns␊ |
1218 | * like for runs of pointers initialzed to the same value can be ␊ |
1219 | * encoded in a few bytes.␊ |
1220 | */␊ |
1221 | uint32_t bind_off;␉/* file offset to binding info */␊ |
1222 | uint32_t bind_size;␉/* size of binding info */␊ |
1223 | ␊ |
1224 | /*␊ |
1225 | * Some C++ programs require dyld to unique symbols so that all␊ |
1226 | * images in the process use the same copy of some code/data.␊ |
1227 | * This step is done after binding. The content of the weak_bind␊ |
1228 | * info is an opcode stream like the bind_info. But it is sorted␊ |
1229 | * alphabetically by symbol name. This enable dyld to walk ␊ |
1230 | * all images with weak binding information in order and look␊ |
1231 | * for collisions. If there are no collisions, dyld does␊ |
1232 | * no updating. That means that some fixups are also encoded␊ |
1233 | * in the bind_info. For instance, all calls to "operator new"␊ |
1234 | * are first bound to libstdc++.dylib using the information␊ |
1235 | * in bind_info. Then if some image overrides operator new␊ |
1236 | * that is detected when the weak_bind information is processed␊ |
1237 | * and the call to operator new is then rebound.␊ |
1238 | */␊ |
1239 | uint32_t weak_bind_off;␉/* file offset to weak binding info */␊ |
1240 | uint32_t weak_bind_size; /* size of weak binding info */␊ |
1241 | ␊ |
1242 | /*␊ |
1243 | * Some uses of external symbols do not need to be bound immediately.␊ |
1244 | * Instead they can be lazily bound on first use. The lazy_bind␊ |
1245 | * are contains a stream of BIND opcodes to bind all lazy symbols.␊ |
1246 | * Normal use is that dyld ignores the lazy_bind section when␊ |
1247 | * loading an image. Instead the static linker arranged for the␊ |
1248 | * lazy pointer to initially point to a helper function which ␊ |
1249 | * pushes the offset into the lazy_bind area for the symbol␊ |
1250 | * needing to be bound, then jumps to dyld which simply adds␊ |
1251 | * the offset to lazy_bind_off to get the information on what ␊ |
1252 | * to bind. ␊ |
1253 | */␊ |
1254 | uint32_t lazy_bind_off;␉/* file offset to lazy binding info */␊ |
1255 | uint32_t lazy_bind_size; /* size of lazy binding infs */␊ |
1256 | ␊ |
1257 | /*␊ |
1258 | * The symbols exported by a dylib are encoded in a trie. This␊ |
1259 | * is a compact representation that factors out common prefixes.␊ |
1260 | * It also reduces LINKEDIT pages in RAM because it encodes all ␊ |
1261 | * information (name, address, flags) in one small, contiguous range.␊ |
1262 | * The export area is a stream of nodes. The first node sequentially␊ |
1263 | * is the start node for the trie. ␊ |
1264 | *␊ |
1265 | * Nodes for a symbol start with a uleb128 that is the length of␊ |
1266 | * the exported symbol information for the string so far.␊ |
1267 | * If there is no exported symbol, the node starts with a zero byte. ␊ |
1268 | * If there is exported info, it follows the length. First is␊ |
1269 | * a uleb128 containing flags. Normally, it is followed by a␊ |
1270 | * uleb128 encoded offset which is location of the content named␊ |
1271 | * by the symbol from the mach_header for the image. If the flags␊ |
1272 | * is EXPORT_SYMBOL_FLAGS_REEXPORT, then following the flags is␊ |
1273 | * a uleb128 encoded library ordinal, then a zero terminated␊ |
1274 | * UTF8 string. If the string is zero length, then the symbol␊ |
1275 | * is re-export from the specified dylib with the same name.␊ |
1276 | *␊ |
1277 | * After the optional exported symbol information is a byte of␊ |
1278 | * how many edges (0-255) that this node has leaving it, ␊ |
1279 | * followed by each edge.␊ |
1280 | * Each edge is a zero terminated UTF8 of the addition chars␊ |
1281 | * in the symbol, followed by a uleb128 offset for the node that␊ |
1282 | * edge points to.␊ |
1283 | * ␊ |
1284 | */␊ |
1285 | uint32_t export_off;␉/* file offset to lazy binding info */␊ |
1286 | uint32_t export_size;␉/* size of lazy binding infs */␊ |
1287 | };␊ |
1288 | ␊ |
1289 | /*␊ |
1290 | * The following are used to encode rebasing information␊ |
1291 | */␊ |
1292 | #define REBASE_TYPE_POINTER␉␉␉␉␉1␊ |
1293 | #define REBASE_TYPE_TEXT_ABSOLUTE32␉␉␉␉2␊ |
1294 | #define REBASE_TYPE_TEXT_PCREL32␉␉␉␉3␊ |
1295 | ␊ |
1296 | #define REBASE_OPCODE_MASK␉␉␉␉␉0xF0␊ |
1297 | #define REBASE_IMMEDIATE_MASK␉␉␉␉␉0x0F␊ |
1298 | #define REBASE_OPCODE_DONE␉␉␉␉␉0x00␊ |
1299 | #define REBASE_OPCODE_SET_TYPE_IMM␉␉␉␉0x10␊ |
1300 | #define REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB␉␉0x20␊ |
1301 | #define REBASE_OPCODE_ADD_ADDR_ULEB␉␉␉␉0x30␊ |
1302 | #define REBASE_OPCODE_ADD_ADDR_IMM_SCALED␉␉␉0x40␊ |
1303 | #define REBASE_OPCODE_DO_REBASE_IMM_TIMES␉␉␉0x50␊ |
1304 | #define REBASE_OPCODE_DO_REBASE_ULEB_TIMES␉␉␉0x60␊ |
1305 | #define REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB␉␉␉0x70␊ |
1306 | #define REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB␉0x80␊ |
1307 | ␊ |
1308 | ␊ |
1309 | /*␊ |
1310 | * The following are used to encode binding information␊ |
1311 | */␊ |
1312 | #define BIND_TYPE_POINTER␉␉␉␉␉1␊ |
1313 | #define BIND_TYPE_TEXT_ABSOLUTE32␉␉␉␉2␊ |
1314 | #define BIND_TYPE_TEXT_PCREL32␉␉␉␉␉3␊ |
1315 | ␊ |
1316 | #define BIND_SPECIAL_DYLIB_SELF␉␉␉␉␉ 0␊ |
1317 | #define BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE␉␉␉-1␊ |
1318 | #define BIND_SPECIAL_DYLIB_FLAT_LOOKUP␉␉␉␉-2␊ |
1319 | ␊ |
1320 | #define BIND_SYMBOL_FLAGS_WEAK_IMPORT␉␉␉␉0x1␊ |
1321 | #define BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION␉␉␉0x8␊ |
1322 | ␊ |
1323 | #define BIND_OPCODE_MASK␉␉␉␉␉0xF0␊ |
1324 | #define BIND_IMMEDIATE_MASK␉␉␉␉␉0x0F␊ |
1325 | #define BIND_OPCODE_DONE␉␉␉␉␉0x00␊ |
1326 | #define BIND_OPCODE_SET_DYLIB_ORDINAL_IMM␉␉␉0x10␊ |
1327 | #define BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB␉␉␉0x20␊ |
1328 | #define BIND_OPCODE_SET_DYLIB_SPECIAL_IMM␉␉␉0x30␊ |
1329 | #define BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM␉␉0x40␊ |
1330 | #define BIND_OPCODE_SET_TYPE_IMM␉␉␉␉0x50␊ |
1331 | #define BIND_OPCODE_SET_ADDEND_SLEB␉␉␉␉0x60␊ |
1332 | #define BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB␉␉␉0x70␊ |
1333 | #define BIND_OPCODE_ADD_ADDR_ULEB␉␉␉␉0x80␊ |
1334 | #define BIND_OPCODE_DO_BIND␉␉␉␉␉0x90␊ |
1335 | #define BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB␉␉␉0xA0␊ |
1336 | #define BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED␉␉␉0xB0␊ |
1337 | #define BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB␉␉0xC0␊ |
1338 | ␊ |
1339 | ␊ |
1340 | /*␊ |
1341 | * The following are used on the flags byte of a terminal node␊ |
1342 | * in the export information.␊ |
1343 | */␊ |
1344 | #define EXPORT_SYMBOL_FLAGS_KIND_MASK␉␉␉␉0x03␊ |
1345 | #define EXPORT_SYMBOL_FLAGS_KIND_REGULAR␉␉␉0x00␊ |
1346 | #define EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL␉␉␉0x01␊ |
1347 | #define EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION␉␉␉0x04␊ |
1348 | #define EXPORT_SYMBOL_FLAGS_REEXPORT␉␉␉␉0x08␊ |
1349 | #define EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER␉␉␉0x10␊ |
1350 | ␊ |
1351 | /*␊ |
1352 | * The symseg_command contains the offset and size of the GNU style␊ |
1353 | * symbol table information as described in the header file <symseg.h>.␊ |
1354 | * The symbol roots of the symbol segments must also be aligned properly␊ |
1355 | * in the file. So the requirement of keeping the offsets aligned to a␊ |
1356 | * multiple of a 4 bytes translates to the length field of the symbol␊ |
1357 | * roots also being a multiple of a long. Also the padding must again be␊ |
1358 | * zeroed. (THIS IS OBSOLETE and no longer supported).␊ |
1359 | */␊ |
1360 | struct symseg_command {␊ |
1361 | ␉uint32_t␉cmd;␉␉/* LC_SYMSEG */␊ |
1362 | ␉uint32_t␉cmdsize;␉/* sizeof(struct symseg_command) */␊ |
1363 | ␉uint32_t␉offset;␉␉/* symbol segment offset */␊ |
1364 | ␉uint32_t␉size;␉␉/* symbol segment size in bytes */␊ |
1365 | };␊ |
1366 | ␊ |
1367 | /*␊ |
1368 | * The ident_command contains a free format string table following the␊ |
1369 | * ident_command structure. The strings are null terminated and the size of␊ |
1370 | * the command is padded out with zero bytes to a multiple of 4 bytes/␊ |
1371 | * (THIS IS OBSOLETE and no longer supported).␊ |
1372 | */␊ |
1373 | struct ident_command {␊ |
1374 | ␉uint32_t cmd;␉␉/* LC_IDENT */␊ |
1375 | ␉uint32_t cmdsize;␉/* strings that follow this command */␊ |
1376 | };␊ |
1377 | ␊ |
1378 | /*␊ |
1379 | * The fvmfile_command contains a reference to a file to be loaded at the␊ |
1380 | * specified virtual address. (Presently, this command is reserved for␊ |
1381 | * internal use. The kernel ignores this command when loading a program into␊ |
1382 | * memory).␊ |
1383 | */␊ |
1384 | struct fvmfile_command {␊ |
1385 | ␉uint32_t cmd;␉␉␉/* LC_FVMFILE */␊ |
1386 | ␉uint32_t cmdsize;␉␉/* includes pathname string */␊ |
1387 | ␉union lc_str␉name;␉␉/* files pathname */␊ |
1388 | ␉uint32_t␉header_addr;␉/* files virtual address */␊ |
1389 | };␊ |
1390 | ␊ |
1391 | /*␊ |
1392 | * Sections of type S_THREAD_LOCAL_VARIABLES contain an array ␊ |
1393 | * of tlv_descriptor structures.␊ |
1394 | */␊ |
1395 | struct tlv_descriptor␊ |
1396 | {␊ |
1397 | ␉void*␉␉(*thunk)(struct tlv_descriptor*);␊ |
1398 | ␉unsigned long␉key;␊ |
1399 | ␉unsigned long␉offset;␊ |
1400 | };␊ |
1401 | ␊ |
1402 | #endif /* _MACHO_LOADER_H_ */␊ |
1403 |