mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-11-24 11:45:27 +01:00
1850 lines
81 KiB
C
1850 lines
81 KiB
C
/*
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* Copyright (c) 1999-2010 Apple Inc. All Rights Reserved.
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*
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* @APPLE_LICENSE_HEADER_START@
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*
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* This file contains Original Code and/or Modifications of Original Code
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* as defined in and that are subject to the Apple Public Source License
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* Version 2.0 (the 'License'). You may not use this file except in
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* compliance with the License. Please obtain a copy of the License at
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* http://www.opensource.apple.com/apsl/ and read it before using this
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* file.
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*
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* The Original Code and all software distributed under the License are
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* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
|
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* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
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* Please see the License for the specific language governing rights and
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* limitations under the License.
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*
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* @APPLE_LICENSE_HEADER_END@
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*/
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#ifndef _MACHO_LOADER_H_
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#define _MACHO_LOADER_H_
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/*
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* This file describes the format of mach object files.
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*/
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//#include <stdint.h>
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/*
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* <mach/machine.h> is needed here for the cpu_type_t and cpu_subtype_t types
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* and contains the constants for the possible values of these types.
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*/
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//#include <mach/machine.h>
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/*
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* <mach/vm_prot.h> is needed here for the vm_prot_t type and contains the
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* constants that are or'ed together for the possible values of this type.
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*/
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//#include <mach/vm_prot.h>
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/*
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* <machine/thread_status.h> is expected to define the flavors of the thread
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* states and the structures of those flavors for each machine.
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*/
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//#include <mach/machine/thread_status.h>
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//#include <architecture/byte_order.h>
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/*
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* The 32-bit mach header appears at the very beginning of the object file for
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* 32-bit architectures.
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*/
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struct mach_header {
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uint32_t magic; /* mach magic number identifier */
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cpu_type_t cputype; /* cpu specifier */
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cpu_subtype_t cpusubtype; /* machine specifier */
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uint32_t filetype; /* type of file */
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uint32_t ncmds; /* number of load commands */
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uint32_t sizeofcmds; /* the size of all the load commands */
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uint32_t flags; /* flags */
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};
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/* Constant for the magic field of the mach_header (32-bit architectures) */
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#define MH_MAGIC 0xfeedface /* the mach magic number */
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#define MH_CIGAM 0xcefaedfe /* NXSwapInt(MH_MAGIC) */
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/*
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* The 64-bit mach header appears at the very beginning of object files for
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* 64-bit architectures.
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*/
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//CFFAEDFE 07000001 03000000 02000000 12000000 D00F0000 01002000 00000000
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//19000000 88010000
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//5F5F5445 58540000 00000000 00000000
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//00002000 80FFFFFF
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struct mach_header_64 {
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uint32_t magic; // mach magic number identifier = 0xFEEDFACF
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cpu_type_t cputype; // cpu specifier UINT32 = 0x01000007
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cpu_subtype_t cpusubtype; // machine specifier = 0x03
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uint32_t filetype; // type of file = 0x02 MH_EXECUTE
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uint32_t ncmds; // number of load commands = 0x12
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uint32_t sizeofcmds; // the size of all the load commands = 0x0FD0
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uint32_t flags; // flags = 0x 0020 0001 (MH_NOUNDEFS | MH_PIE)
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uint32_t reserved; // reserved
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};
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/* Constant for the magic field of the mach_header_64 (64-bit architectures) */
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#define MH_MAGIC_64 0xfeedfacf /* the 64-bit mach magic number */
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#define MH_CIGAM_64 0xcffaedfe /* NXSwapInt(MH_MAGIC_64) */
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/*
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* The layout of the file depends on the filetype. For all but the MH_OBJECT
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* file type the segments are padded out and aligned on a segment alignment
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* boundary for efficient demand pageing. The MH_EXECUTE, MH_FVMLIB, MH_DYLIB,
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* MH_DYLINKER and MH_BUNDLE file types also have the headers included as part
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* of their first segment.
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*
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* The file type MH_OBJECT is a compact format intended as output of the
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* assembler and input (and possibly output) of the link editor (the .o
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* format). All sections are in one unnamed segment with no segment padding.
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* This format is used as an executable format when the file is so small the
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* segment padding greatly increases its size.
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*
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* The file type MH_PRELOAD is an executable format intended for things that
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* are not executed under the kernel (proms, stand alones, kernels, etc). The
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* format can be executed under the kernel but may demand paged it and not
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* preload it before execution.
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*
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* A core file is in MH_CORE format and can be any in an arbritray legal
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* Mach-O file.
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*
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* Constants for the filetype field of the mach_header
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*/
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#define MH_OBJECT 0x1 /* relocatable object file */
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#define MH_EXECUTE 0x2 /* demand paged executable file */
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#define MH_FVMLIB 0x3 /* fixed VM shared library file */
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#define MH_CORE 0x4 /* core file */
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#define MH_PRELOAD 0x5 /* preloaded executable file */
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#define MH_DYLIB 0x6 /* dynamically bound shared library */
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#define MH_DYLINKER 0x7 /* dynamic link editor */
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#define MH_BUNDLE 0x8 /* dynamically bound bundle file */
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#define MH_DYLIB_STUB 0x9 /* shared library stub for static */
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/* linking only, no section contents */
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#define MH_DSYM 0xa /* companion file with only debug */
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/* sections */
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#define MH_KEXT_BUNDLE 0xb /* x86_64 kexts */
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#define MH_KEXT_CACHE 0xc //???
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/* Constants for the flags field of the mach_header */
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#define MH_NOUNDEFS 0x1 /* the object file has no undefined
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references */
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#define MH_INCRLINK 0x2 /* the object file is the output of an
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incremental link against a base file
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and can't be link edited again */
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#define MH_DYLDLINK 0x4 /* the object file is input for the
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dynamic linker and can't be staticly
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link edited again */
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#define MH_BINDATLOAD 0x8 /* the object file's undefined
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references are bound by the dynamic
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linker when loaded. */
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#define MH_PREBOUND 0x10 /* the file has its dynamic undefined
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references prebound. */
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#define MH_SPLIT_SEGS 0x20 /* the file has its read-only and
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read-write segments split */
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#define MH_LAZY_INIT 0x40 /* the shared library init routine is
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to be run lazily via catching memory
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faults to its writeable segments
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(obsolete) */
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#define MH_TWOLEVEL 0x80 /* the image is using two-level name
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space bindings */
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#define MH_FORCE_FLAT 0x100 /* the executable is forcing all images
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to use flat name space bindings */
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#define MH_NOMULTIDEFS 0x200 /* this umbrella guarantees no multiple
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defintions of symbols in its
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sub-images so the two-level namespace
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hints can always be used. */
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#define MH_NOFIXPREBINDING 0x400 /* do not have dyld notify the
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prebinding agent about this
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executable */
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#define MH_PREBINDABLE 0x800 /* the binary is not prebound but can
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have its prebinding redone. only used
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when MH_PREBOUND is not set. */
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#define MH_ALLMODSBOUND 0x1000 /* indicates that this binary binds to
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all two-level namespace modules of
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its dependent libraries. only used
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when MH_PREBINDABLE and MH_TWOLEVEL
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are both set. */
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#define MH_SUBSECTIONS_VIA_SYMBOLS 0x2000/* safe to divide up the sections into
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sub-sections via symbols for dead
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code stripping */
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#define MH_CANONICAL 0x4000 /* the binary has been canonicalized
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via the unprebind operation */
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#define MH_WEAK_DEFINES 0x8000 /* the final linked image contains
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external weak symbols */
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#define MH_BINDS_TO_WEAK 0x10000 /* the final linked image uses
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weak symbols */
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#define MH_ALLOW_STACK_EXECUTION 0x20000/* When this bit is set, all stacks
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in the task will be given stack
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execution privilege. Only used in
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MH_EXECUTE filetypes. */
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#define MH_ROOT_SAFE 0x40000 /* When this bit is set, the binary
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declares it is safe for use in
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processes with uid zero */
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#define MH_SETUID_SAFE 0x80000 /* When this bit is set, the binary
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declares it is safe for use in
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processes when issetugid() is true */
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#define MH_NO_REEXPORTED_DYLIBS 0x100000 /* When this bit is set on a dylib,
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the static linker does not need to
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examine dependent dylibs to see
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if any are re-exported */
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#define MH_PIE 0x200000 /* When this bit is set, the OS will
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load the main executable at a
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random address. Only used in
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MH_EXECUTE filetypes. */
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#define MH_DEAD_STRIPPABLE_DYLIB 0x400000 /* Only for use on dylibs. When
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linking against a dylib that
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has this bit set, the static linker
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will automatically not create a
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LC_LOAD_DYLIB load command to the
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dylib if no symbols are being
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referenced from the dylib. */
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#define MH_HAS_TLV_DESCRIPTORS 0x800000 /* Contains a section of type
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S_THREAD_LOCAL_VARIABLES */
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#define MH_NO_HEAP_EXECUTION 0x1000000 /* When this bit is set, the OS will
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run the main executable with
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a non-executable heap even on
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platforms (e.g. i386) that don't
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require it. Only used in MH_EXECUTE
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filetypes. */
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/*
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* The load commands directly follow the mach_header. The total size of all
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* of the commands is given by the sizeofcmds field in the mach_header. All
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* load commands must have as their first two fields cmd and cmdsize. The cmd
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* field is filled in with a constant for that command type. Each command type
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* has a structure specifically for it. The cmdsize field is the size in bytes
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* of the particular load command structure plus anything that follows it that
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* is a part of the load command (i.e. section structures, strings, etc.). To
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* advance to the next load command the cmdsize can be added to the offset or
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* pointer of the current load command. The cmdsize for 32-bit architectures
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* MUST be a multiple of 4 bytes and for 64-bit architectures MUST be a multiple
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* of 8 bytes (these are forever the maximum alignment of any load commands).
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* The padded bytes must be zero. All tables in the object file must also
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* follow these rules so the file can be memory mapped. Otherwise the pointers
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* to these tables will not work well or at all on some machines. With all
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* padding zeroed like objects will compare byte for byte.
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*/
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struct load_command {
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uint32_t cmd; /* type of load command */
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uint32_t cmdsize; /* total size of command in bytes */
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};
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/*
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* After MacOS X 10.1 when a new load command is added that is required to be
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* understood by the dynamic linker for the image to execute properly the
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* LC_REQ_DYLD bit will be or'ed into the load command constant. If the dynamic
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* linker sees such a load command it it does not understand will issue a
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* "unknown load command required for execution" error and refuse to use the
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* image. Other load commands without this bit that are not understood will
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* simply be ignored.
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*/
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#define LC_REQ_DYLD 0x80000000
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/* Constants for the cmd field of all load commands, the type */
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#define LC_SEGMENT 0x1 /* segment of this file to be mapped */
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#define LC_SYMTAB 0x2 /* link-edit stab symbol table info */
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#define LC_SYMSEG 0x3 /* link-edit gdb symbol table info (obsolete) */
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#define LC_THREAD 0x4 /* thread */
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#define LC_UNIXTHREAD 0x5 /* unix thread (includes a stack) */
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#define LC_LOADFVMLIB 0x6 /* load a specified fixed VM shared library */
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#define LC_IDFVMLIB 0x7 /* fixed VM shared library identification */
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#define LC_IDENT 0x8 /* object identification info (obsolete) */
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#define LC_FVMFILE 0x9 /* fixed VM file inclusion (internal use) */
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#define LC_PREPAGE 0xa /* prepage command (internal use) */
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#define LC_DYSYMTAB 0xb /* dynamic link-edit symbol table info */
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#define LC_LOAD_DYLIB 0xc /* load a dynamically linked shared library */
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#define LC_ID_DYLIB 0xd /* dynamically linked shared lib ident */
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#define LC_LOAD_DYLINKER 0xe /* load a dynamic linker */
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#define LC_ID_DYLINKER 0xf /* dynamic linker identification */
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#define LC_PREBOUND_DYLIB 0x10 /* modules prebound for a dynamically */
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/* linked shared library */
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#define LC_ROUTINES 0x11 /* image routines */
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#define LC_SUB_FRAMEWORK 0x12 /* sub framework */
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#define LC_SUB_UMBRELLA 0x13 /* sub umbrella */
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#define LC_SUB_CLIENT 0x14 /* sub client */
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#define LC_SUB_LIBRARY 0x15 /* sub library */
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#define LC_TWOLEVEL_HINTS 0x16 /* two-level namespace lookup hints */
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#define LC_PREBIND_CKSUM 0x17 /* prebind checksum */
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/*
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* load a dynamically linked shared library that is allowed to be missing
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* (all symbols are weak imported).
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*/
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#define LC_LOAD_WEAK_DYLIB (0x18 | LC_REQ_DYLD)
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#define LC_SEGMENT_64 0x19 /* 64-bit segment of this file to be
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mapped */
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#define LC_ROUTINES_64 0x1a /* 64-bit image routines */
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#define LC_UUID 0x1b /* the uuid */
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#define LC_RPATH (0x1c | LC_REQ_DYLD) /* runpath additions */
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#define LC_CODE_SIGNATURE 0x1d /* local of code signature */
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#define LC_SEGMENT_SPLIT_INFO 0x1e /* local of info to split segments */
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#define LC_REEXPORT_DYLIB (0x1f | LC_REQ_DYLD) /* load and re-export dylib */
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#define LC_LAZY_LOAD_DYLIB 0x20 /* delay load of dylib until first use */
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#define LC_ENCRYPTION_INFO 0x21 /* encrypted segment information */
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#define LC_DYLD_INFO 0x22 /* compressed dyld information */
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#define LC_DYLD_INFO_ONLY (0x22|LC_REQ_DYLD) /* compressed dyld information only */
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#define LC_LOAD_UPWARD_DYLIB (0x23 | LC_REQ_DYLD) /* load upward dylib */
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#define LC_VERSION_MIN_MACOSX 0x24 /* build for macOS min OS version */
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#define LC_VERSION_MIN_IPHONEOS 0x25 /* build for iPhoneOS min OS version */
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#define LC_FUNCTION_STARTS 0x26 /* compressed table of function start addresses */
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||
#define LC_DYLD_ENVIRONMENT 0x27 /* string for dyld to treat
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||
like environment variable */
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#define LC_MAIN (0x28|LC_REQ_DYLD) /* replacement for LC_UNIXTHREAD */
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||
#define LC_DATA_IN_CODE 0x29 /* table of non-instructions in __text */
|
||
#define LC_SOURCE_VERSION 0x2A /* source version used to build binary */
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||
#define LC_DYLIB_CODE_SIGN_DRS 0x2B /* Code signing DRs copied from linked dylibs */
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#define LC_ENCRYPTION_INFO_64 0x2C /* 64-bit encrypted segment information */
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#define LC_LINKER_OPTION 0x2D /* linker options in MH_OBJECT files */
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#define LC_LINKER_OPTIMIZATION_HINT 0x2E /* optimization hints in MH_OBJECT files */
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#define LC_VERSION_MIN_TVOS 0x2F /* build for AppleTV min OS version */
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||
#define LC_VERSION_MIN_WATCHOS 0x30 /* build for Watch min OS version */
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||
#define LC_NOTE 0x31 /* arbitrary data included within a Mach-O file */
|
||
#define LC_BUILD_VERSION 0x32 /* build for platform min OS version */
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#define LC_DYLD_EXPORTS_TRIE (0x33 | LC_REQ_DYLD) /* used with linkedit_data_command, payload is trie */
|
||
#define LC_DYLD_CHAINED_FIXUPS (0x34 | LC_REQ_DYLD) /* used with linkedit_data_command */
|
||
#define LC_KEXT (0x35 | LC_REQ_DYLD)
|
||
|
||
|
||
/*
|
||
* A variable length string in a load command is represented by an lc_str
|
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* union. The strings are stored just after the load command structure and
|
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* the offset is from the start of the load command structure. The size
|
||
* of the string is reflected in the cmdsize field of the load command.
|
||
* Once again any padded bytes to bring the cmdsize field to a multiple
|
||
* of 4 bytes must be zero.
|
||
*/
|
||
union lc_str {
|
||
uint32_t offset; /* offset to the string */
|
||
#ifndef __LP64__
|
||
char *ptr; /* pointer to the string */
|
||
#endif
|
||
};
|
||
typedef union lc_str lc_str;
|
||
|
||
/*
|
||
* The segment load command indicates that a part of this file is to be
|
||
* mapped into the task's address space. The size of this segment in memory,
|
||
* vmsize, maybe equal to or larger than the amount to map from this file,
|
||
* filesize. The file is mapped starting at fileoff to the beginning of
|
||
* the segment in memory, vmaddr. The rest of the memory of the segment,
|
||
* if any, is allocated zero fill on demand. The segment's maximum virtual
|
||
* memory protection and initial virtual memory protection are specified
|
||
* by the maxprot and initprot fields. If the segment has sections then the
|
||
* section structures directly follow the segment command and their size is
|
||
* reflected in cmdsize.
|
||
*/
|
||
struct segment_command { /* for 32-bit architectures */
|
||
uint32_t cmd; /* LC_SEGMENT */
|
||
uint32_t cmdsize; /* includes sizeof section structs */
|
||
char segname[16]; /* segment name */
|
||
uint32_t vmaddr; /* memory address of this segment */
|
||
uint32_t vmsize; /* memory size of this segment */
|
||
uint32_t fileoff; /* file offset of this segment */
|
||
uint32_t filesize; /* amount to map from the file */
|
||
vm_prot_t maxprot; /* maximum VM protection */
|
||
vm_prot_t initprot; /* initial VM protection */
|
||
uint32_t nsects; /* number of sections in segment */
|
||
uint32_t flags; /* flags */
|
||
};
|
||
|
||
/*
|
||
* The 64-bit segment load command indicates that a part of this file is to be
|
||
* mapped into a 64-bit task's address space. If the 64-bit segment has
|
||
* sections then section_64 structures directly follow the 64-bit segment
|
||
* command and their size is reflected in cmdsize.
|
||
*/
|
||
struct segment_command_64 { /* for 64-bit architectures */
|
||
uint32_t cmd; /* LC_SEGMENT_64 */
|
||
uint32_t cmdsize; /* includes sizeof section_64 structs */
|
||
char segname[16]; /* segment name */
|
||
uint64_t vmaddr; /* memory address of this segment */
|
||
uint64_t vmsize; /* memory size of this segment */
|
||
uint64_t fileoff; /* file offset of this segment */ //0x28
|
||
uint64_t filesize; /* amount to map from the file */ //0x30
|
||
vm_prot_t maxprot; /* maximum VM protection */ //38
|
||
vm_prot_t initprot; /* initial VM protection */ //3c
|
||
uint32_t nsects; /* number of sections in segment */ //40
|
||
uint32_t flags; /* flags */ //44
|
||
// struct section_64 sect[]; //0x48 if nsect > 0 len=nsects
|
||
};
|
||
|
||
/* Constants for the flags field of the segment_command */
|
||
#define SG_HIGHVM 0x1 /* the file contents for this segment is for
|
||
the high part of the VM space, the low part
|
||
is zero filled (for stacks in core files) */
|
||
#define SG_FVMLIB 0x2 /* this segment is the VM that is allocated by
|
||
a fixed VM library, for overlap checking in
|
||
the link editor */
|
||
#define SG_NORELOC 0x4 /* this segment has nothing that was relocated
|
||
in it and nothing relocated to it, that is
|
||
it maybe safely replaced without relocation*/
|
||
#define SG_PROTECTED_VERSION_1 0x8 /* This segment is protected. If the
|
||
segment starts at file offset 0, the
|
||
first page of the segment is not
|
||
protected. All other pages of the
|
||
segment are protected. */
|
||
#define SG_READ_ONLY 0x10 /* This segment is made read-only after fixups */
|
||
|
||
|
||
/*
|
||
* A segment is made up of zero or more sections. Non-MH_OBJECT files have
|
||
* all of their segments with the proper sections in each, and padded to the
|
||
* specified segment alignment when produced by the link editor. The first
|
||
* segment of a MH_EXECUTE and MH_FVMLIB format file contains the mach_header
|
||
* and load commands of the object file before its first section. The zero
|
||
* fill sections are always last in their segment (in all formats). This
|
||
* allows the zeroed segment padding to be mapped into memory where zero fill
|
||
* sections might be. The gigabyte zero fill sections, those with the section
|
||
* type S_GB_ZEROFILL, can only be in a segment with sections of this type.
|
||
* These segments are then placed after all other segments.
|
||
*
|
||
* The MH_OBJECT format has all of its sections in one segment for
|
||
* compactness. There is no padding to a specified segment boundary and the
|
||
* mach_header and load commands are not part of the segment.
|
||
*
|
||
* Sections with the same section name, sectname, going into the same segment,
|
||
* segname, are combined by the link editor. The resulting section is aligned
|
||
* to the maximum alignment of the combined sections and is the new section's
|
||
* alignment. The combined sections are aligned to their original alignment in
|
||
* the combined section. Any padded bytes to get the specified alignment are
|
||
* zeroed.
|
||
*
|
||
* The format of the relocation entries referenced by the reloff and nreloc
|
||
* fields of the section structure for mach object files is described in the
|
||
* header file <reloc.h>.
|
||
*/
|
||
struct section { /* for 32-bit architectures */
|
||
char sectname[16]; /* name of this section */
|
||
char segname[16]; /* segment this section goes in */
|
||
uint32_t addr; /* memory address of this section */
|
||
uint32_t size; /* size in bytes of this section */
|
||
uint32_t offset; /* file offset of this section */
|
||
uint32_t align; /* section alignment (power of 2) */
|
||
uint32_t reloff; /* file offset of relocation entries */
|
||
uint32_t nreloc; /* number of relocation entries */
|
||
uint32_t flags; /* flags (section type and attributes)*/
|
||
uint32_t reserved1; /* reserved (for offset or index) */
|
||
uint32_t reserved2; /* reserved (for count or sizeof) */
|
||
};
|
||
|
||
struct section_64 { /* for 64-bit architectures */
|
||
char sectname[16]; /* name of this section */
|
||
char segname[16]; /* segment this section goes in */
|
||
uint64_t addr; /* memory address of this section */
|
||
uint64_t size; /* size in bytes of this section */
|
||
uint32_t offset; /* file offset of this section */
|
||
uint32_t align; /* section alignment (power of 2) */
|
||
uint32_t reloff; /* file offset of relocation entries */
|
||
uint32_t nreloc; /* number of relocation entries */
|
||
uint32_t flags; /* flags (section type and attributes)*/
|
||
uint32_t reserved1; /* reserved (for offset or index) */
|
||
uint32_t reserved2; /* reserved (for count or sizeof) */
|
||
uint32_t reserved3; /* reserved */
|
||
};
|
||
|
||
/*
|
||
* The flags field of a section structure is separated into two parts a section
|
||
* type and section attributes. The section types are mutually exclusive (it
|
||
* can only have one type) but the section attributes are not (it may have more
|
||
* than one attribute).
|
||
*/
|
||
#define SECTION_TYPE 0x000000ff /* 256 section types */
|
||
#define SECTION_ATTRIBUTES 0xffffff00 /* 24 section attributes */
|
||
|
||
/* Constants for the type of a section */
|
||
#define S_REGULAR 0x0 /* regular section */
|
||
#define S_ZEROFILL 0x1 /* zero fill on demand section */
|
||
#define S_CSTRING_LITERALS 0x2 /* section with only literal C strings*/
|
||
#define S_4BYTE_LITERALS 0x3 /* section with only 4 byte literals */
|
||
#define S_8BYTE_LITERALS 0x4 /* section with only 8 byte literals */
|
||
#define S_LITERAL_POINTERS 0x5 /* section with only pointers to */
|
||
/* literals */
|
||
/*
|
||
* For the two types of symbol pointers sections and the symbol stubs section
|
||
* they have indirect symbol table entries. For each of the entries in the
|
||
* section the indirect symbol table entries, in corresponding order in the
|
||
* indirect symbol table, start at the index stored in the reserved1 field
|
||
* of the section structure. Since the indirect symbol table entries
|
||
* correspond to the entries in the section the number of indirect symbol table
|
||
* entries is inferred from the size of the section divided by the size of the
|
||
* entries in the section. For symbol pointers sections the size of the entries
|
||
* in the section is 4 bytes and for symbol stubs sections the byte size of the
|
||
* stubs is stored in the reserved2 field of the section structure.
|
||
*/
|
||
#define S_NON_LAZY_SYMBOL_POINTERS 0x6 /* section with only non-lazy
|
||
symbol pointers */
|
||
#define S_LAZY_SYMBOL_POINTERS 0x7 /* section with only lazy symbol
|
||
pointers */
|
||
#define S_SYMBOL_STUBS 0x8 /* section with only symbol
|
||
stubs, byte size of stub in
|
||
the reserved2 field */
|
||
#define S_MOD_INIT_FUNC_POINTERS 0x9 /* section with only function
|
||
pointers for initialization*/
|
||
#define S_MOD_TERM_FUNC_POINTERS 0xa /* section with only function
|
||
pointers for termination */
|
||
#define S_COALESCED 0xb /* section contains symbols that
|
||
are to be coalesced */
|
||
#define S_GB_ZEROFILL 0xc /* zero fill on demand section
|
||
(that can be larger than 4
|
||
gigabytes) */
|
||
#define S_INTERPOSING 0xd /* section with only pairs of
|
||
function pointers for
|
||
interposing */
|
||
#define S_16BYTE_LITERALS 0xe /* section with only 16 byte
|
||
literals */
|
||
#define S_DTRACE_DOF 0xf /* section contains
|
||
DTrace Object Format */
|
||
#define S_LAZY_DYLIB_SYMBOL_POINTERS 0x10 /* section with only lazy
|
||
symbol pointers to lazy
|
||
loaded dylibs */
|
||
/*
|
||
* Section types to support thread local variables
|
||
*/
|
||
#define S_THREAD_LOCAL_REGULAR 0x11 /* template of initial
|
||
values for TLVs */
|
||
#define S_THREAD_LOCAL_ZEROFILL 0x12 /* template of initial
|
||
values for TLVs */
|
||
#define S_THREAD_LOCAL_VARIABLES 0x13 /* TLV descriptors */
|
||
#define S_THREAD_LOCAL_VARIABLE_POINTERS 0x14 /* pointers to TLV
|
||
descriptors */
|
||
#define S_THREAD_LOCAL_INIT_FUNCTION_POINTERS 0x15 /* functions to call
|
||
to initialize TLV
|
||
values */
|
||
#define S_INIT_FUNC_OFFSETS 0x16 /* 32-bit offsets to
|
||
initializers */
|
||
|
||
|
||
/*
|
||
* Constants for the section attributes part of the flags field of a section
|
||
* structure.
|
||
*/
|
||
#define SECTION_ATTRIBUTES_USR 0xff000000 /* User setable attributes */
|
||
#define S_ATTR_PURE_INSTRUCTIONS 0x80000000 /* section contains only true
|
||
machine instructions */
|
||
#define S_ATTR_NO_TOC 0x40000000 /* section contains coalesced
|
||
symbols that are not to be
|
||
in a ranlib table of
|
||
contents */
|
||
#define S_ATTR_STRIP_STATIC_SYMS 0x20000000 /* ok to strip static symbols
|
||
in this section in files
|
||
with the MH_DYLDLINK flag */
|
||
#define S_ATTR_NO_DEAD_STRIP 0x10000000 /* no dead stripping */
|
||
#define S_ATTR_LIVE_SUPPORT 0x08000000 /* blocks are live if they
|
||
reference live blocks */
|
||
#define S_ATTR_SELF_MODIFYING_CODE 0x04000000 /* Used with i386 code stubs
|
||
written on by dyld */
|
||
/*
|
||
* If a segment contains any sections marked with S_ATTR_DEBUG then all
|
||
* sections in that segment must have this attribute. No section other than
|
||
* a section marked with this attribute may reference the contents of this
|
||
* section. A section with this attribute may contain no symbols and must have
|
||
* a section type S_REGULAR. The static linker will not copy section contents
|
||
* from sections with this attribute into its output file. These sections
|
||
* generally contain DWARF debugging info.
|
||
*/
|
||
#define S_ATTR_DEBUG 0x02000000 /* a debug section */
|
||
#define SECTION_ATTRIBUTES_SYS 0x00ffff00 /* system setable attributes */
|
||
#define S_ATTR_SOME_INSTRUCTIONS 0x00000400 /* section contains some
|
||
machine instructions */
|
||
#define S_ATTR_EXT_RELOC 0x00000200 /* section has external
|
||
relocation entries */
|
||
#define S_ATTR_LOC_RELOC 0x00000100 /* section has local
|
||
relocation entries */
|
||
|
||
|
||
/*
|
||
* The names of segments and sections in them are mostly meaningless to the
|
||
* link-editor. But there are few things to support traditional UNIX
|
||
* executables that require the link-editor and assembler to use some names
|
||
* agreed upon by convention.
|
||
*
|
||
* The initial protection of the "__TEXT" segment has write protection turned
|
||
* off (not writeable).
|
||
*
|
||
* The link-editor will allocate common symbols at the end of the "__common"
|
||
* section in the "__DATA" segment. It will create the section and segment
|
||
* if needed.
|
||
*/
|
||
|
||
/* The currently known segment names and the section names in those segments */
|
||
|
||
#define SEG_PAGEZERO "__PAGEZERO" /* the pagezero segment which has no */
|
||
/* protections and catches NULL */
|
||
/* references for MH_EXECUTE files */
|
||
|
||
|
||
#define SEG_TEXT "__TEXT" /* the tradition UNIX text segment */
|
||
#define SECT_TEXT "__text" /* the real text part of the text */
|
||
/* section no headers, and no padding */
|
||
#define SECT_FVMLIB_INIT0 "__fvmlib_init0" /* the fvmlib initialization */
|
||
/* section */
|
||
#define SECT_FVMLIB_INIT1 "__fvmlib_init1" /* the section following the */
|
||
/* fvmlib initialization */
|
||
/* section */
|
||
|
||
#define SEG_DATA "__DATA" /* the tradition UNIX data segment */
|
||
#define SECT_DATA "__data" /* the real initialized data section */
|
||
/* no padding, no bss overlap */
|
||
#define SECT_BSS "__bss" /* the real uninitialized data section*/
|
||
/* no padding */
|
||
#define SECT_COMMON "__common" /* the section common symbols are */
|
||
/* allocated in by the link editor */
|
||
|
||
#define SEG_OBJC "__OBJC" /* objective-C runtime segment */
|
||
#define SECT_OBJC_SYMBOLS "__symbol_table" /* symbol table */
|
||
#define SECT_OBJC_MODULES "__module_info" /* module information */
|
||
#define SECT_OBJC_STRINGS "__selector_strs" /* string table */
|
||
#define SECT_OBJC_REFS "__selector_refs" /* string table */
|
||
|
||
#define SEG_ICON "__ICON" /* the icon segment */
|
||
#define SECT_ICON_HEADER "__header" /* the icon headers */
|
||
#define SECT_ICON_TIFF "__tiff" /* the icons in tiff format */
|
||
|
||
#define SEG_LINKEDIT "__LINKEDIT" /* the segment containing all structs */
|
||
/* created and maintained by the link */
|
||
/* editor. Created with -seglinkedit */
|
||
/* option to ld(1) for MH_EXECUTE and */
|
||
/* FVMLIB file types only */
|
||
|
||
#define SEG_UNIXSTACK "__UNIXSTACK" /* the unix stack segment */
|
||
|
||
#define SEG_IMPORT "__IMPORT" /* the segment for the self (dyld) */
|
||
/* modifing code stubs that has read, */
|
||
/* write and execute permissions */
|
||
|
||
/*
|
||
* Fixed virtual memory shared libraries are identified by two things. The
|
||
* target pathname (the name of the library as found for execution), and the
|
||
* minor version number. The address of where the headers are loaded is in
|
||
* header_addr. (THIS IS OBSOLETE and no longer supported).
|
||
*/
|
||
struct fvmshlib {
|
||
/*union*/ lc_str name; /* library's target pathname */
|
||
uint32_t minor_version; /* library's minor version number */
|
||
uint32_t header_addr; /* library's header address */
|
||
};
|
||
typedef struct fvmshlib fvmshlib;
|
||
|
||
/*
|
||
* A fixed virtual shared library (filetype == MH_FVMLIB in the mach header)
|
||
* contains a fvmlib_command (cmd == LC_IDFVMLIB) to identify the library.
|
||
* An object that uses a fixed virtual shared library also contains a
|
||
* fvmlib_command (cmd == LC_LOADFVMLIB) for each library it uses.
|
||
* (THIS IS OBSOLETE and no longer supported).
|
||
*/
|
||
struct fvmlib_command {
|
||
uint32_t cmd; /* LC_IDFVMLIB or LC_LOADFVMLIB */
|
||
uint32_t cmdsize; /* includes pathname string */
|
||
/*struct*/ fvmshlib fvmlib; /* the library identification */
|
||
};
|
||
|
||
/*
|
||
* Dynamicly linked shared libraries are identified by two things. The
|
||
* pathname (the name of the library as found for execution), and the
|
||
* compatibility version number. The pathname must match and the compatibility
|
||
* number in the user of the library must be greater than or equal to the
|
||
* library being used. The time stamp is used to record the time a library was
|
||
* built and copied into user so it can be use to determined if the library used
|
||
* at runtime is exactly the same as used to built the program.
|
||
*/
|
||
struct dylib {
|
||
union lc_str name; /* library's path name */
|
||
uint32_t timestamp; /* library's build time stamp */
|
||
uint32_t current_version; /* library's current version number */
|
||
uint32_t compatibility_version; /* library's compatibility vers number*/
|
||
};
|
||
|
||
/*
|
||
* A dynamically linked shared library (filetype == MH_DYLIB in the mach header)
|
||
* contains a dylib_command (cmd == LC_ID_DYLIB) to identify the library.
|
||
* An object that uses a dynamically linked shared library also contains a
|
||
* dylib_command (cmd == LC_LOAD_DYLIB, LC_LOAD_WEAK_DYLIB, or
|
||
* LC_REEXPORT_DYLIB) for each library it uses.
|
||
*/
|
||
struct dylib_command {
|
||
uint32_t cmd; /* LC_ID_DYLIB, LC_LOAD_{,WEAK_}DYLIB,
|
||
LC_REEXPORT_DYLIB */
|
||
uint32_t cmdsize; /* includes pathname string */
|
||
struct dylib dylib; /* the library identification */
|
||
};
|
||
|
||
/*
|
||
* A dynamically linked shared library may be a subframework of an umbrella
|
||
* framework. If so it will be linked with "-umbrella umbrella_name" where
|
||
* Where "umbrella_name" is the name of the umbrella framework. A subframework
|
||
* can only be linked against by its umbrella framework or other subframeworks
|
||
* that are part of the same umbrella framework. Otherwise the static link
|
||
* editor produces an error and states to link against the umbrella framework.
|
||
* The name of the umbrella framework for subframeworks is recorded in the
|
||
* following structure.
|
||
*/
|
||
struct sub_framework_command {
|
||
uint32_t cmd; /* LC_SUB_FRAMEWORK */
|
||
uint32_t cmdsize; /* includes umbrella string */
|
||
union lc_str umbrella; /* the umbrella framework name */
|
||
};
|
||
|
||
/*
|
||
* For dynamically linked shared libraries that are subframework of an umbrella
|
||
* framework they can allow clients other than the umbrella framework or other
|
||
* subframeworks in the same umbrella framework. To do this the subframework
|
||
* is built with "-allowable_client client_name" and an LC_SUB_CLIENT load
|
||
* command is created for each -allowable_client flag. The client_name is
|
||
* usually a framework name. It can also be a name used for bundles clients
|
||
* where the bundle is built with "-client_name client_name".
|
||
*/
|
||
struct sub_client_command {
|
||
uint32_t cmd; /* LC_SUB_CLIENT */
|
||
uint32_t cmdsize; /* includes client string */
|
||
union lc_str client; /* the client name */
|
||
};
|
||
|
||
/*
|
||
* A dynamically linked shared library may be a sub_umbrella of an umbrella
|
||
* framework. If so it will be linked with "-sub_umbrella umbrella_name" where
|
||
* Where "umbrella_name" is the name of the sub_umbrella framework. When
|
||
* staticly linking when -twolevel_namespace is in effect a twolevel namespace
|
||
* umbrella framework will only cause its subframeworks and those frameworks
|
||
* listed as sub_umbrella frameworks to be implicited linked in. Any other
|
||
* dependent dynamic libraries will not be linked it when -twolevel_namespace
|
||
* is in effect. The primary library recorded by the static linker when
|
||
* resolving a symbol in these libraries will be the umbrella framework.
|
||
* Zero or more sub_umbrella frameworks may be use by an umbrella framework.
|
||
* The name of a sub_umbrella framework is recorded in the following structure.
|
||
*/
|
||
struct sub_umbrella_command {
|
||
uint32_t cmd; /* LC_SUB_UMBRELLA */
|
||
uint32_t cmdsize; /* includes sub_umbrella string */
|
||
union lc_str sub_umbrella; /* the sub_umbrella framework name */
|
||
};
|
||
|
||
/*
|
||
* A dynamically linked shared library may be a sub_library of another shared
|
||
* library. If so it will be linked with "-sub_library library_name" where
|
||
* Where "library_name" is the name of the sub_library shared library. When
|
||
* staticly linking when -twolevel_namespace is in effect a twolevel namespace
|
||
* shared library will only cause its subframeworks and those frameworks
|
||
* listed as sub_umbrella frameworks and libraries listed as sub_libraries to
|
||
* be implicited linked in. Any other dependent dynamic libraries will not be
|
||
* linked it when -twolevel_namespace is in effect. The primary library
|
||
* recorded by the static linker when resolving a symbol in these libraries
|
||
* will be the umbrella framework (or dynamic library). Zero or more sub_library
|
||
* shared libraries may be use by an umbrella framework or (or dynamic library).
|
||
* The name of a sub_library framework is recorded in the following structure.
|
||
* For example /usr/lib/libobjc_profile.A.dylib would be recorded as "libobjc".
|
||
*/
|
||
struct sub_library_command {
|
||
uint32_t cmd; /* LC_SUB_LIBRARY */
|
||
uint32_t cmdsize; /* includes sub_library string */
|
||
union lc_str sub_library; /* the sub_library name */
|
||
};
|
||
|
||
/*
|
||
* A program (filetype == MH_EXECUTE) that is
|
||
* prebound to its dynamic libraries has one of these for each library that
|
||
* the static linker used in prebinding. It contains a bit vector for the
|
||
* modules in the library. The bits indicate which modules are bound (1) and
|
||
* which are not (0) from the library. The bit for module 0 is the low bit
|
||
* of the first byte. So the bit for the Nth module is:
|
||
* (linked_modules[N/8] >> N%8) & 1
|
||
*/
|
||
struct prebound_dylib_command {
|
||
uint32_t cmd; /* LC_PREBOUND_DYLIB */
|
||
uint32_t cmdsize; /* includes strings */
|
||
union lc_str name; /* library's path name */
|
||
uint32_t nmodules; /* number of modules in library */
|
||
union lc_str linked_modules; /* bit vector of linked modules */
|
||
};
|
||
|
||
/*
|
||
* A program that uses a dynamic linker contains a dylinker_command to identify
|
||
* the name of the dynamic linker (LC_LOAD_DYLINKER). And a dynamic linker
|
||
* contains a dylinker_command to identify the dynamic linker (LC_ID_DYLINKER).
|
||
* A file can have at most one of these.
|
||
* This struct is also used for the LC_DYLD_ENVIRONMENT load command and
|
||
* contains string for dyld to treat like environment variable.
|
||
*/
|
||
struct dylinker_command {
|
||
uint32_t cmd; /* LC_ID_DYLINKER, LC_LOAD_DYLINKER or
|
||
LC_DYLD_ENVIRONMENT */
|
||
uint32_t cmdsize; /* includes pathname string */
|
||
union lc_str name; /* dynamic linker's path name */
|
||
};
|
||
|
||
/*
|
||
* Thread commands contain machine-specific data structures suitable for
|
||
* use in the thread state primitives. The machine specific data structures
|
||
* follow the struct thread_command as follows.
|
||
* Each flavor of machine specific data structure is preceded by an unsigned
|
||
* long constant for the flavor of that data structure, an uint32_t
|
||
* that is the count of longs of the size of the state data structure and then
|
||
* the state data structure follows. This triple may be repeated for many
|
||
* flavors. The constants for the flavors, counts and state data structure
|
||
* definitions are expected to be in the header file <machine/thread_status.h>.
|
||
* These machine specific data structures sizes must be multiples of
|
||
* 4 bytes The cmdsize reflects the total size of the thread_command
|
||
* and all of the sizes of the constants for the flavors, counts and state
|
||
* data structures.
|
||
*
|
||
* For executable objects that are unix processes there will be one
|
||
* thread_command (cmd == LC_UNIXTHREAD) created for it by the link-editor.
|
||
* This is the same as a LC_THREAD, except that a stack is automatically
|
||
* created (based on the shell's limit for the stack size). Command arguments
|
||
* and environment variables are copied onto that stack.
|
||
*/
|
||
struct thread_command {
|
||
uint32_t cmd; /* LC_THREAD or LC_UNIXTHREAD */
|
||
uint32_t cmdsize; /* total size of this command */
|
||
/* uint32_t flavor flavor of thread state */
|
||
/* uint32_t count count of longs in thread state */
|
||
/* struct XXX_thread_state state thread state for this flavor */
|
||
/* ... */
|
||
};
|
||
|
||
/*
|
||
* The routines command contains the address of the dynamic shared library
|
||
* initialization routine and an index into the module table for the module
|
||
* that defines the routine. Before any modules are used from the library the
|
||
* dynamic linker fully binds the module that defines the initialization routine
|
||
* and then calls it. This gets called before any module initialization
|
||
* routines (used for C++ static constructors) in the library.
|
||
*/
|
||
struct routines_command { /* for 32-bit architectures */
|
||
uint32_t cmd; /* LC_ROUTINES */
|
||
uint32_t cmdsize; /* total size of this command */
|
||
uint32_t init_address; /* address of initialization routine */
|
||
uint32_t init_module; /* index into the module table that */
|
||
/* the init routine is defined in */
|
||
uint32_t reserved1;
|
||
uint32_t reserved2;
|
||
uint32_t reserved3;
|
||
uint32_t reserved4;
|
||
uint32_t reserved5;
|
||
uint32_t reserved6;
|
||
};
|
||
|
||
/*
|
||
* The 64-bit routines command. Same use as above.
|
||
*/
|
||
struct routines_command_64 { /* for 64-bit architectures */
|
||
uint32_t cmd; /* LC_ROUTINES_64 */
|
||
uint32_t cmdsize; /* total size of this command */
|
||
uint64_t init_address; /* address of initialization routine */
|
||
uint64_t init_module; /* index into the module table that */
|
||
/* the init routine is defined in */
|
||
uint64_t reserved1;
|
||
uint64_t reserved2;
|
||
uint64_t reserved3;
|
||
uint64_t reserved4;
|
||
uint64_t reserved5;
|
||
uint64_t reserved6;
|
||
};
|
||
|
||
/*
|
||
* The symtab_command contains the offsets and sizes of the link-edit 4.3BSD
|
||
* "stab" style symbol table information as described in the header files
|
||
* <nlist.h> and <stab.h>.
|
||
*/
|
||
struct symtab_command {
|
||
uint32_t cmd; /* LC_SYMTAB == 2 */
|
||
uint32_t cmdsize; /* sizeof(struct symtab_command) */
|
||
uint32_t symoff; /* symbol table offset */
|
||
uint32_t nsyms; /* number of symbol table entries */
|
||
uint32_t stroff; /* string table offset */
|
||
uint32_t strsize; /* string table size in bytes */
|
||
};
|
||
|
||
/*
|
||
* This is the second set of the symbolic information which is used to support
|
||
* the data structures for the dynamically link editor.
|
||
*
|
||
* The original set of symbolic information in the symtab_command which contains
|
||
* the symbol and string tables must also be present when this load command is
|
||
* present. When this load command is present the symbol table is organized
|
||
* into three groups of symbols:
|
||
* local symbols (static and debugging symbols) - grouped by module
|
||
* defined external symbols - grouped by module (sorted by name if not lib)
|
||
* undefined external symbols (sorted by name if MH_BINDATLOAD is not set,
|
||
* and in order the were seen by the static
|
||
* linker if MH_BINDATLOAD is set)
|
||
* In this load command there are offsets and counts to each of the three groups
|
||
* of symbols.
|
||
*
|
||
* This load command contains a the offsets and sizes of the following new
|
||
* symbolic information tables:
|
||
* table of contents
|
||
* module table
|
||
* reference symbol table
|
||
* indirect symbol table
|
||
* The first three tables above (the table of contents, module table and
|
||
* reference symbol table) are only present if the file is a dynamically linked
|
||
* shared library. For executable and object modules, which are files
|
||
* containing only one module, the information that would be in these three
|
||
* tables is determined as follows:
|
||
* table of contents - the defined external symbols are sorted by name
|
||
* module table - the file contains only one module so everything in the
|
||
* file is part of the module.
|
||
* reference symbol table - is the defined and undefined external symbols
|
||
*
|
||
* For dynamically linked shared library files this load command also contains
|
||
* offsets and sizes to the pool of relocation entries for all sections
|
||
* separated into two groups:
|
||
* external relocation entries
|
||
* local relocation entries
|
||
* For executable and object modules the relocation entries continue to hang
|
||
* off the section structures.
|
||
*/
|
||
struct dysymtab_command {
|
||
uint32_t cmd; /* LC_DYSYMTAB == 0x0b */
|
||
uint32_t cmdsize; /* sizeof(struct dysymtab_command) */
|
||
|
||
/*
|
||
* The symbols indicated by symoff and nsyms of the LC_SYMTAB load command
|
||
* are grouped into the following three groups:
|
||
* local symbols (further grouped by the module they are from)
|
||
* defined external symbols (further grouped by the module they are from)
|
||
* undefined symbols
|
||
*
|
||
* The local symbols are used only for debugging. The dynamic binding
|
||
* process may have to use them to indicate to the debugger the local
|
||
* symbols for a module that is being bound.
|
||
*
|
||
* The last two groups are used by the dynamic binding process to do the
|
||
* binding (indirectly through the module table and the reference symbol
|
||
* table when this is a dynamically linked shared library file).
|
||
*/
|
||
uint32_t ilocalsym; /* index to local symbols */
|
||
uint32_t nlocalsym; /* number of local symbols */
|
||
|
||
uint32_t iextdefsym;/* index to externally defined symbols */
|
||
uint32_t nextdefsym;/* number of externally defined symbols */
|
||
|
||
uint32_t iundefsym; /* index to undefined symbols */
|
||
uint32_t nundefsym; /* number of undefined symbols */
|
||
|
||
/*
|
||
* For the for the dynamic binding process to find which module a symbol
|
||
* is defined in the table of contents is used (analogous to the ranlib
|
||
* structure in an archive) which maps defined external symbols to modules
|
||
* they are defined in. This exists only in a dynamically linked shared
|
||
* library file. For executable and object modules the defined external
|
||
* symbols are sorted by name and is use as the table of contents.
|
||
*/
|
||
uint32_t tocoff; /* file offset to table of contents */
|
||
uint32_t ntoc; /* number of entries in table of contents */
|
||
|
||
/*
|
||
* To support dynamic binding of "modules" (whole object files) the symbol
|
||
* table must reflect the modules that the file was created from. This is
|
||
* done by having a module table that has indexes and counts into the merged
|
||
* tables for each module. The module structure that these two entries
|
||
* refer to is described below. This exists only in a dynamically linked
|
||
* shared library file. For executable and object modules the file only
|
||
* contains one module so everything in the file belongs to the module.
|
||
*/
|
||
uint32_t modtaboff; /* file offset to module table */
|
||
uint32_t nmodtab; /* number of module table entries */
|
||
|
||
/*
|
||
* To support dynamic module binding the module structure for each module
|
||
* indicates the external references (defined and undefined) each module
|
||
* makes. For each module there is an offset and a count into the
|
||
* reference symbol table for the symbols that the module references.
|
||
* This exists only in a dynamically linked shared library file. For
|
||
* executable and object modules the defined external symbols and the
|
||
* undefined external symbols indicates the external references.
|
||
*/
|
||
uint32_t extrefsymoff; /* offset to referenced symbol table */
|
||
uint32_t nextrefsyms; /* number of referenced symbol table entries */
|
||
|
||
/*
|
||
* The sections that contain "symbol pointers" and "routine stubs" have
|
||
* indexes and (implied counts based on the size of the section and fixed
|
||
* size of the entry) into the "indirect symbol" table for each pointer
|
||
* and stub. For every section of these two types the index into the
|
||
* indirect symbol table is stored in the section header in the field
|
||
* reserved1. An indirect symbol table entry is simply a 32bit index into
|
||
* the symbol table to the symbol that the pointer or stub is referring to.
|
||
* The indirect symbol table is ordered to match the entries in the section.
|
||
*/
|
||
uint32_t indirectsymoff; /* file offset to the indirect symbol table */
|
||
uint32_t nindirectsyms; /* number of indirect symbol table entries */
|
||
|
||
/*
|
||
* To support relocating an individual module in a library file quickly the
|
||
* external relocation entries for each module in the library need to be
|
||
* accessed efficiently. Since the relocation entries can't be accessed
|
||
* through the section headers for a library file they are separated into
|
||
* groups of local and external entries further grouped by module. In this
|
||
* case the presents of this load command who's extreloff, nextrel,
|
||
* locreloff and nlocrel fields are non-zero indicates that the relocation
|
||
* entries of non-merged sections are not referenced through the section
|
||
* structures (and the reloff and nreloc fields in the section headers are
|
||
* set to zero).
|
||
*
|
||
* Since the relocation entries are not accessed through the section headers
|
||
* this requires the r_address field to be something other than a section
|
||
* offset to identify the item to be relocated. In this case r_address is
|
||
* set to the offset from the vmaddr of the first LC_SEGMENT command.
|
||
* For MH_SPLIT_SEGS images r_address is set to the the offset from the
|
||
* vmaddr of the first read-write LC_SEGMENT command.
|
||
*
|
||
* The relocation entries are grouped by module and the module table
|
||
* entries have indexes and counts into them for the group of external
|
||
* relocation entries for that the module.
|
||
*
|
||
* For sections that are merged across modules there must not be any
|
||
* remaining external relocation entries for them (for merged sections
|
||
* remaining relocation entries must be local).
|
||
*/
|
||
uint32_t extreloff; /* offset to external relocation entries */
|
||
uint32_t nextrel; /* number of external relocation entries */
|
||
|
||
/*
|
||
* All the local relocation entries are grouped together (they are not
|
||
* grouped by their module since they are only used if the object is moved
|
||
* from it staticly link edited address).
|
||
*/
|
||
uint32_t locreloff; /* offset to local relocation entries */
|
||
uint32_t nlocrel; /* number of local relocation entries */
|
||
|
||
};
|
||
|
||
/*
|
||
* An indirect symbol table entry is simply a 32bit index into the symbol table
|
||
* to the symbol that the pointer or stub is refering to. Unless it is for a
|
||
* non-lazy symbol pointer section for a defined symbol which strip(1) as
|
||
* removed. In which case it has the value INDIRECT_SYMBOL_LOCAL. If the
|
||
* symbol was also absolute INDIRECT_SYMBOL_ABS is or'ed with that.
|
||
*/
|
||
#define INDIRECT_SYMBOL_LOCAL 0x80000000
|
||
#define INDIRECT_SYMBOL_ABS 0x40000000
|
||
|
||
|
||
/* a table of contents entry */
|
||
struct dylib_table_of_contents {
|
||
uint32_t symbol_index; /* the defined external symbol
|
||
(index into the symbol table) */
|
||
uint32_t module_index; /* index into the module table this symbol
|
||
is defined in */
|
||
};
|
||
|
||
/* a module table entry */
|
||
struct dylib_module {
|
||
uint32_t module_name; /* the module name (index into string table) */
|
||
|
||
uint32_t iextdefsym; /* index into externally defined symbols */
|
||
uint32_t nextdefsym; /* number of externally defined symbols */
|
||
uint32_t irefsym; /* index into reference symbol table */
|
||
uint32_t nrefsym; /* number of reference symbol table entries */
|
||
uint32_t ilocalsym; /* index into symbols for local symbols */
|
||
uint32_t nlocalsym; /* number of local symbols */
|
||
|
||
uint32_t iextrel; /* index into external relocation entries */
|
||
uint32_t nextrel; /* number of external relocation entries */
|
||
|
||
uint32_t iinit_iterm; /* low 16 bits are the index into the init
|
||
section, high 16 bits are the index into
|
||
the term section */
|
||
uint32_t ninit_nterm; /* low 16 bits are the number of init section
|
||
entries, high 16 bits are the number of
|
||
term section entries */
|
||
|
||
uint32_t /* for this module address of the start of */
|
||
objc_module_info_addr; /* the (__OBJC,__module_info) section */
|
||
uint32_t /* for this module size of */
|
||
objc_module_info_size; /* the (__OBJC,__module_info) section */
|
||
};
|
||
|
||
/* a 64-bit module table entry */
|
||
struct dylib_module_64 {
|
||
uint32_t module_name; /* the module name (index into string table) */
|
||
|
||
uint32_t iextdefsym; /* index into externally defined symbols */
|
||
uint32_t nextdefsym; /* number of externally defined symbols */
|
||
uint32_t irefsym; /* index into reference symbol table */
|
||
uint32_t nrefsym; /* number of reference symbol table entries */
|
||
uint32_t ilocalsym; /* index into symbols for local symbols */
|
||
uint32_t nlocalsym; /* number of local symbols */
|
||
|
||
uint32_t iextrel; /* index into external relocation entries */
|
||
uint32_t nextrel; /* number of external relocation entries */
|
||
|
||
uint32_t iinit_iterm; /* low 16 bits are the index into the init
|
||
section, high 16 bits are the index into
|
||
the term section */
|
||
uint32_t ninit_nterm; /* low 16 bits are the number of init section
|
||
entries, high 16 bits are the number of
|
||
term section entries */
|
||
|
||
uint32_t /* for this module size of */
|
||
objc_module_info_size; /* the (__OBJC,__module_info) section */
|
||
uint64_t /* for this module address of the start of */
|
||
objc_module_info_addr; /* the (__OBJC,__module_info) section */
|
||
};
|
||
|
||
/*
|
||
* The entries in the reference symbol table are used when loading the module
|
||
* (both by the static and dynamic link editors) and if the module is unloaded
|
||
* or replaced. Therefore all external symbols (defined and undefined) are
|
||
* listed in the module's reference table. The flags describe the type of
|
||
* reference that is being made. The constants for the flags are defined in
|
||
* <mach-o/nlist.h> as they are also used for symbol table entries.
|
||
*/
|
||
struct dylib_reference {
|
||
uint32_t isym:24, /* index into the symbol table */
|
||
flags:8; /* flags to indicate the type of reference */
|
||
};
|
||
|
||
/*
|
||
* The twolevel_hints_command contains the offset and number of hints in the
|
||
* two-level namespace lookup hints table.
|
||
*/
|
||
struct twolevel_hints_command {
|
||
uint32_t cmd; /* LC_TWOLEVEL_HINTS */
|
||
uint32_t cmdsize; /* sizeof(struct twolevel_hints_command) */
|
||
uint32_t offset; /* offset to the hint table */
|
||
uint32_t nhints; /* number of hints in the hint table */
|
||
};
|
||
|
||
/*
|
||
* The entries in the two-level namespace lookup hints table are twolevel_hint
|
||
* structs. These provide hints to the dynamic link editor where to start
|
||
* looking for an undefined symbol in a two-level namespace image. The
|
||
* isub_image field is an index into the sub-images (sub-frameworks and
|
||
* sub-umbrellas list) that made up the two-level image that the undefined
|
||
* symbol was found in when it was built by the static link editor. If
|
||
* isub-image is 0 the the symbol is expected to be defined in library and not
|
||
* in the sub-images. If isub-image is non-zero it is an index into the array
|
||
* of sub-images for the umbrella with the first index in the sub-images being
|
||
* 1. The array of sub-images is the ordered list of sub-images of the umbrella
|
||
* that would be searched for a symbol that has the umbrella recorded as its
|
||
* primary library. The table of contents index is an index into the
|
||
* library's table of contents. This is used as the starting point of the
|
||
* binary search or a directed linear search.
|
||
*/
|
||
struct twolevel_hint {
|
||
uint32_t
|
||
isub_image:8, /* index into the sub images */
|
||
itoc:24; /* index into the table of contents */
|
||
};
|
||
|
||
/*
|
||
* The prebind_cksum_command contains the value of the original check sum for
|
||
* prebound files or zero. When a prebound file is first created or modified
|
||
* for other than updating its prebinding information the value of the check sum
|
||
* is set to zero. When the file has it prebinding re-done and if the value of
|
||
* the check sum is zero the original check sum is calculated and stored in
|
||
* cksum field of this load command in the output file. If when the prebinding
|
||
* is re-done and the cksum field is non-zero it is left unchanged from the
|
||
* input file.
|
||
*/
|
||
struct prebind_cksum_command {
|
||
uint32_t cmd; /* LC_PREBIND_CKSUM */
|
||
uint32_t cmdsize; /* sizeof(struct prebind_cksum_command) */
|
||
uint32_t cksum; /* the check sum or zero */
|
||
};
|
||
|
||
/*
|
||
* The uuid load command contains a single 128-bit unique random number that
|
||
* identifies an object produced by the static link editor.
|
||
*/
|
||
struct uuid_command {
|
||
uint32_t cmd; /* LC_UUID */
|
||
uint32_t cmdsize; /* sizeof(struct uuid_command) */
|
||
uint8_t uuid[16]; /* the 128-bit uuid */
|
||
};
|
||
|
||
/*
|
||
* The rpath_command contains a path which at runtime should be added to
|
||
* the current run path used to find @rpath prefixed dylibs.
|
||
*/
|
||
struct rpath_command {
|
||
uint32_t cmd; /* LC_RPATH */
|
||
uint32_t cmdsize; /* includes string */
|
||
union lc_str path; /* path to add to run path */
|
||
};
|
||
|
||
/*
|
||
* The linkedit_data_command contains the offsets and sizes of a blob
|
||
* of data in the __LINKEDIT segment.
|
||
*/
|
||
struct linkedit_data_command {
|
||
uint32_t cmd; /* LC_CODE_SIGNATURE, LC_SEGMENT_SPLIT_INFO,
|
||
LC_FUNCTION_STARTS, LC_DATA_IN_CODE,
|
||
LC_DYLIB_CODE_SIGN_DRS,
|
||
LC_LINKER_OPTIMIZATION_HINT,
|
||
LC_DYLD_EXPORTS_TRIE, or
|
||
LC_DYLD_CHAINED_FIXUPS. */
|
||
uint32_t cmdsize; /* sizeof(struct linkedit_data_command) */
|
||
uint32_t dataoff; /* file offset of data in __LINKEDIT segment */
|
||
uint32_t datasize; /* file size of data in __LINKEDIT segment */
|
||
};
|
||
|
||
/*
|
||
* The encryption_info_command contains the file offset and size of an
|
||
* of an encrypted segment.
|
||
*/
|
||
struct encryption_info_command {
|
||
uint32_t cmd; /* LC_ENCRYPTION_INFO */
|
||
uint32_t cmdsize; /* sizeof(struct encryption_info_command) */
|
||
uint32_t cryptoff; /* file offset of encrypted range */
|
||
uint32_t cryptsize; /* file size of encrypted range */
|
||
uint32_t cryptid; /* which enryption system,
|
||
0 means not-encrypted yet */
|
||
};
|
||
|
||
/*
|
||
* The encryption_info_command_64 contains the file offset and size of an
|
||
* of an encrypted segment (for use in x86_64 targets).
|
||
*/
|
||
struct encryption_info_command_64 {
|
||
uint32_t cmd; /* LC_ENCRYPTION_INFO_64 */
|
||
uint32_t cmdsize; /* sizeof(struct encryption_info_command_64) */
|
||
uint32_t cryptoff; /* file offset of encrypted range */
|
||
uint32_t cryptsize; /* file size of encrypted range */
|
||
uint32_t cryptid; /* which enryption system,
|
||
0 means not-encrypted yet */
|
||
uint32_t pad; /* padding to make this struct's size a multiple
|
||
of 8 bytes */
|
||
};
|
||
|
||
/*
|
||
* The version_min_command contains the min OS version on which this
|
||
* binary was built to run.
|
||
*/
|
||
struct version_min_command {
|
||
uint32_t cmd; /* LC_VERSION_MIN_MACOSX or
|
||
LC_VERSION_MIN_IPHONEOS */
|
||
uint32_t cmdsize; /* sizeof(struct min_version_command) */
|
||
uint32_t version; /* X.Y.Z is encoded in nibbles xxxx.yy.zz */
|
||
uint32_t sdk; /* X.Y.Z is encoded in nibbles xxxx.yy.zz */
|
||
};
|
||
|
||
/*
|
||
* The build_version_command contains the min OS version on which this
|
||
* binary was built to run for its platform. The list of known platforms and
|
||
* tool values following it.
|
||
*/
|
||
struct build_version_command {
|
||
uint32_t cmd; /* LC_BUILD_VERSION */
|
||
uint32_t cmdsize; /* sizeof(struct build_version_command) plus */
|
||
/* ntools * sizeof(struct build_tool_version) */
|
||
uint32_t platform; /* platform */
|
||
uint32_t minos; /* X.Y.Z is encoded in nibbles xxxx.yy.zz */
|
||
uint32_t sdk; /* X.Y.Z is encoded in nibbles xxxx.yy.zz */
|
||
uint32_t ntools; /* number of tool entries following this */
|
||
};
|
||
|
||
struct build_tool_version {
|
||
uint32_t tool; /* enum for the tool */
|
||
uint32_t version; /* version number of the tool */
|
||
};
|
||
|
||
/* Known values for the platform field above. */
|
||
#define PLATFORM_MACOS 1
|
||
#define PLATFORM_IOS 2
|
||
#define PLATFORM_TVOS 3
|
||
#define PLATFORM_WATCHOS 4
|
||
#define PLATFORM_BRIDGEOS 5
|
||
#define PLATFORM_IOSMAC 6
|
||
#define PLATFORM_IOSSIMULATOR 7
|
||
#define PLATFORM_TVOSSIMULATOR 8
|
||
#define PLATFORM_WATCHOSSIMULATOR 9
|
||
#define PLATFORM_DRIVERKIT 10
|
||
|
||
/* Known values for the tool field above. */
|
||
#define TOOL_CLANG 1
|
||
#define TOOL_SWIFT 2
|
||
#define TOOL_LD 3
|
||
|
||
|
||
/*
|
||
* The dyld_info_command contains the file offsets and sizes of
|
||
* the new compressed form of the information dyld needs to
|
||
* load the image. This information is used by dyld on Mac OS X
|
||
* 10.6 and later. All information pointed to by this command
|
||
* is encoded using byte streams, so no endian swapping is needed
|
||
* to interpret it.
|
||
*/
|
||
struct dyld_info_command {
|
||
uint32_t cmd; /* LC_DYLD_INFO or LC_DYLD_INFO_ONLY */
|
||
uint32_t cmdsize; /* sizeof(struct dyld_info_command) */
|
||
|
||
/*
|
||
* Dyld rebases an image whenever dyld loads it at an address different
|
||
* from its preferred address. The rebase information is a stream
|
||
* of byte sized opcodes whose symbolic names start with REBASE_OPCODE_.
|
||
* Conceptually the rebase information is a table of tuples:
|
||
* <seg-index, seg-offset, type>
|
||
* The opcodes are a compressed way to encode the table by only
|
||
* encoding when a column changes. In addition simple patterns
|
||
* like "every n'th offset for m times" can be encoded in a few
|
||
* bytes.
|
||
*/
|
||
uint32_t rebase_off; /* file offset to rebase info */
|
||
uint32_t rebase_size; /* size of rebase info */
|
||
|
||
/*
|
||
* Dyld binds an image during the loading process, if the image
|
||
* requires any pointers to be initialized to symbols in other images.
|
||
* The bind information is a stream of byte sized
|
||
* opcodes whose symbolic names start with BIND_OPCODE_.
|
||
* Conceptually the bind information is a table of tuples:
|
||
* <seg-index, seg-offset, type, symbol-library-ordinal, symbol-name, addend>
|
||
* The opcodes are a compressed way to encode the table by only
|
||
* encoding when a column changes. In addition simple patterns
|
||
* like for runs of pointers initialzed to the same value can be
|
||
* encoded in a few bytes.
|
||
*/
|
||
uint32_t bind_off; /* file offset to binding info */
|
||
uint32_t bind_size; /* size of binding info */
|
||
|
||
/*
|
||
* Some C++ programs require dyld to unique symbols so that all
|
||
* images in the process use the same copy of some code/data.
|
||
* This step is done after binding. The content of the weak_bind
|
||
* info is an opcode stream like the bind_info. But it is sorted
|
||
* alphabetically by symbol name. This enable dyld to walk
|
||
* all images with weak binding information in order and look
|
||
* for collisions. If there are no collisions, dyld does
|
||
* no updating. That means that some fixups are also encoded
|
||
* in the bind_info. For instance, all calls to "operator new"
|
||
* are first bound to libstdc++.dylib using the information
|
||
* in bind_info. Then if some image overrides operator new
|
||
* that is detected when the weak_bind information is processed
|
||
* and the call to operator new is then rebound.
|
||
*/
|
||
uint32_t weak_bind_off; /* file offset to weak binding info */
|
||
uint32_t weak_bind_size; /* size of weak binding info */
|
||
|
||
/*
|
||
* Some uses of external symbols do not need to be bound immediately.
|
||
* Instead they can be lazily bound on first use. The lazy_bind
|
||
* are contains a stream of BIND opcodes to bind all lazy symbols.
|
||
* Normal use is that dyld ignores the lazy_bind section when
|
||
* loading an image. Instead the static linker arranged for the
|
||
* lazy pointer to initially point to a helper function which
|
||
* pushes the offset into the lazy_bind area for the symbol
|
||
* needing to be bound, then jumps to dyld which simply adds
|
||
* the offset to lazy_bind_off to get the information on what
|
||
* to bind.
|
||
*/
|
||
uint32_t lazy_bind_off; /* file offset to lazy binding info */
|
||
uint32_t lazy_bind_size; /* size of lazy binding infs */
|
||
|
||
/*
|
||
* The symbols exported by a dylib are encoded in a trie. This
|
||
* is a compact representation that factors out common prefixes.
|
||
* It also reduces LINKEDIT pages in RAM because it encodes all
|
||
* information (name, address, flags) in one small, contiguous range.
|
||
* The export area is a stream of nodes. The first node sequentially
|
||
* is the start node for the trie.
|
||
*
|
||
* Nodes for a symbol start with a uleb128 that is the length of
|
||
* the exported symbol information for the string so far.
|
||
* If there is no exported symbol, the node starts with a zero byte.
|
||
* If there is exported info, it follows the length.
|
||
*
|
||
* First is a uleb128 containing flags. Normally, it is followed by
|
||
* a uleb128 encoded offset which is location of the content named
|
||
* by the symbol from the mach_header for the image. If the flags
|
||
* is EXPORT_SYMBOL_FLAGS_REEXPORT, then following the flags is
|
||
* a uleb128 encoded library ordinal, then a zero terminated
|
||
* UTF8 string. If the string is zero length, then the symbol
|
||
* is re-export from the specified dylib with the same name.
|
||
* If the flags is EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER, then following
|
||
* the flags is two uleb128s: the stub offset and the resolver offset.
|
||
* The stub is used by non-lazy pointers. The resolver is used
|
||
* by lazy pointers and must be called to get the actual address to use.
|
||
*
|
||
* After the optional exported symbol information is a byte of
|
||
* how many edges (0-255) that this node has leaving it,
|
||
* followed by each edge.
|
||
* Each edge is a zero terminated UTF8 of the addition chars
|
||
* in the symbol, followed by a uleb128 offset for the node that
|
||
* edge points to.
|
||
*
|
||
*/
|
||
uint32_t export_off; /* file offset to lazy binding info */
|
||
uint32_t export_size; /* size of lazy binding infs */
|
||
};
|
||
|
||
/*
|
||
* The following are used to encode rebasing information
|
||
*/
|
||
#define REBASE_TYPE_POINTER 1
|
||
#define REBASE_TYPE_TEXT_ABSOLUTE32 2
|
||
#define REBASE_TYPE_TEXT_PCREL32 3
|
||
|
||
#define REBASE_OPCODE_MASK 0xF0
|
||
#define REBASE_IMMEDIATE_MASK 0x0F
|
||
#define REBASE_OPCODE_DONE 0x00
|
||
#define REBASE_OPCODE_SET_TYPE_IMM 0x10
|
||
#define REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB 0x20
|
||
#define REBASE_OPCODE_ADD_ADDR_ULEB 0x30
|
||
#define REBASE_OPCODE_ADD_ADDR_IMM_SCALED 0x40
|
||
#define REBASE_OPCODE_DO_REBASE_IMM_TIMES 0x50
|
||
#define REBASE_OPCODE_DO_REBASE_ULEB_TIMES 0x60
|
||
#define REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB 0x70
|
||
#define REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB 0x80
|
||
|
||
|
||
/*
|
||
* The following are used to encode binding information
|
||
*/
|
||
#define BIND_TYPE_POINTER 1
|
||
#define BIND_TYPE_TEXT_ABSOLUTE32 2
|
||
#define BIND_TYPE_TEXT_PCREL32 3
|
||
|
||
#define BIND_SPECIAL_DYLIB_SELF 0
|
||
#define BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE -1
|
||
#define BIND_SPECIAL_DYLIB_FLAT_LOOKUP -2
|
||
|
||
#define BIND_SYMBOL_FLAGS_WEAK_IMPORT 0x1
|
||
#define BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION 0x8
|
||
|
||
#define BIND_OPCODE_MASK 0xF0
|
||
#define BIND_IMMEDIATE_MASK 0x0F
|
||
#define BIND_OPCODE_DONE 0x00
|
||
#define BIND_OPCODE_SET_DYLIB_ORDINAL_IMM 0x10
|
||
#define BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB 0x20
|
||
#define BIND_OPCODE_SET_DYLIB_SPECIAL_IMM 0x30
|
||
#define BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM 0x40
|
||
#define BIND_OPCODE_SET_TYPE_IMM 0x50
|
||
#define BIND_OPCODE_SET_ADDEND_SLEB 0x60
|
||
#define BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB 0x70
|
||
#define BIND_OPCODE_ADD_ADDR_ULEB 0x80
|
||
#define BIND_OPCODE_DO_BIND 0x90
|
||
#define BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB 0xA0
|
||
#define BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED 0xB0
|
||
#define BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB 0xC0
|
||
#define BIND_OPCODE_THREADED 0xD0
|
||
#define BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB 0x00
|
||
#define BIND_SUBOPCODE_THREADED_APPLY 0x01
|
||
|
||
|
||
/*
|
||
* The following are used on the flags byte of a terminal node
|
||
* in the export information.
|
||
*/
|
||
#define EXPORT_SYMBOL_FLAGS_KIND_MASK 0x03
|
||
#define EXPORT_SYMBOL_FLAGS_KIND_REGULAR 0x00
|
||
#define EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL 0x01
|
||
#define EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION 0x04
|
||
#define EXPORT_SYMBOL_FLAGS_REEXPORT 0x08
|
||
#define EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER 0x10
|
||
|
||
/*
|
||
* The linker_option_command contains linker options embedded in object files.
|
||
*/
|
||
struct linker_option_command {
|
||
uint32_t cmd; /* LC_LINKER_OPTION only used in MH_OBJECT filetypes */
|
||
uint32_t cmdsize;
|
||
uint32_t count; /* number of strings */
|
||
/* concatenation of zero terminated UTF8 strings.
|
||
Zero filled at end to align */
|
||
};
|
||
|
||
|
||
/*
|
||
* The symseg_command contains the offset and size of the GNU style
|
||
* symbol table information as described in the header file <symseg.h>.
|
||
* The symbol roots of the symbol segments must also be aligned properly
|
||
* in the file. So the requirement of keeping the offsets aligned to a
|
||
* multiple of a 4 bytes translates to the length field of the symbol
|
||
* roots also being a multiple of a long. Also the padding must again be
|
||
* zeroed. (THIS IS OBSOLETE and no longer supported).
|
||
*/
|
||
struct symseg_command {
|
||
uint32_t cmd; /* LC_SYMSEG */
|
||
uint32_t cmdsize; /* sizeof(struct symseg_command) */
|
||
uint32_t offset; /* symbol segment offset */
|
||
uint32_t size; /* symbol segment size in bytes */
|
||
};
|
||
|
||
/*
|
||
* The ident_command contains a free format string table following the
|
||
* ident_command structure. The strings are null terminated and the size of
|
||
* the command is padded out with zero bytes to a multiple of 4 bytes/
|
||
* (THIS IS OBSOLETE and no longer supported).
|
||
*/
|
||
struct ident_command {
|
||
uint32_t cmd; /* LC_IDENT */
|
||
uint32_t cmdsize; /* strings that follow this command */
|
||
};
|
||
|
||
/*
|
||
* The fvmfile_command contains a reference to a file to be loaded at the
|
||
* specified virtual address. (Presently, this command is reserved for
|
||
* internal use. The kernel ignores this command when loading a program into
|
||
* memory).
|
||
*/
|
||
struct fvmfile_command {
|
||
uint32_t cmd; /* LC_FVMFILE */
|
||
uint32_t cmdsize; /* includes pathname string */
|
||
union lc_str name; /* files pathname */
|
||
uint32_t header_addr; /* files virtual address */
|
||
};
|
||
|
||
|
||
/*
|
||
* The entry_point_command is a replacement for thread_command.
|
||
* It is used for main executables to specify the location (file offset)
|
||
* of main(). If -stack_size was used at link time, the stacksize
|
||
* field will contain the stack size need for the main thread.
|
||
*/
|
||
struct entry_point_command {
|
||
uint32_t cmd; /* LC_MAIN only used in MH_EXECUTE filetypes */
|
||
uint32_t cmdsize; /* 24 */
|
||
uint64_t entryoff; /* file (__TEXT) offset of main() */
|
||
uint64_t stacksize;/* if not zero, initial stack size */
|
||
};
|
||
|
||
|
||
/*
|
||
* The source_version_command is an optional load command containing
|
||
* the version of the sources used to build the binary.
|
||
*/
|
||
struct source_version_command {
|
||
uint32_t cmd; /* LC_SOURCE_VERSION */
|
||
uint32_t cmdsize; /* 16 */
|
||
uint64_t version; /* A.B.C.D.E packed as a24.b10.c10.d10.e10 */
|
||
};
|
||
|
||
|
||
/*
|
||
* The LC_DATA_IN_CODE load commands uses a linkedit_data_command
|
||
* to point to an array of data_in_code_entry entries. Each entry
|
||
* describes a range of data in a code section. This load command
|
||
* is only used in final linked images.
|
||
*/
|
||
struct data_in_code_entry {
|
||
uint32_t offset; /* from mach_header to start of data range*/
|
||
uint16_t length; /* number of bytes in data range */
|
||
uint16_t kind; /* a DICE_KIND_* value */
|
||
};
|
||
#define DICE_KIND_DATA 0x0001 /* L$start$data$... label */
|
||
#define DICE_KIND_JUMP_TABLE8 0x0002 /* L$start$jt8$... label */
|
||
#define DICE_KIND_JUMP_TABLE16 0x0003 /* L$start$jt16$... label */
|
||
#define DICE_KIND_JUMP_TABLE32 0x0004 /* L$start$jt32$... label */
|
||
#define DICE_KIND_ABS_JUMP_TABLE32 0x0005 /* L$start$jta32$... label */
|
||
|
||
|
||
|
||
/*
|
||
* Sections of type S_THREAD_LOCAL_VARIABLES contain an array
|
||
* of tlv_descriptor structures.
|
||
*/
|
||
struct tlv_descriptor
|
||
{
|
||
void* (*thunk)(struct tlv_descriptor*);
|
||
unsigned long key;
|
||
unsigned long offset;
|
||
};
|
||
|
||
/*
|
||
* LC_NOTE commands describe a region of arbitrary data included in a Mach-O
|
||
* file. Its initial use is to record extra data in MH_CORE files.
|
||
*/
|
||
struct note_command {
|
||
uint32_t cmd; /* LC_NOTE */
|
||
uint32_t cmdsize; /* sizeof(struct note_command) */
|
||
char data_owner[16]; /* owner name for this LC_NOTE */
|
||
uint64_t offset; /* file offset of this data */
|
||
uint64_t size; /* length of data region */
|
||
};
|
||
|
||
//kexts cache
|
||
struct command_35 {
|
||
uint32_t cmd; //0x35 - LC_KEXT
|
||
uint32_t cmdsize; //0x38 - short name, 0x48 - long name, ...
|
||
uint64_t offset; /* file offset of this data */
|
||
uint64_t size; /* length of data region */
|
||
uint32_t res1; //=0x20
|
||
uint32_t res2; //=0x00
|
||
char name[]; //kext name [16] or [32]
|
||
// align to 8 byte boundary
|
||
};
|
||
|
||
//from file nlist.h
|
||
//struct symtab_command {
|
||
// uint32_t cmd; /* LC_SYMTAB == 2 */
|
||
// uint32_t cmdsize; /* sizeof(struct symtab_command) */
|
||
// uint32_t symoff; /* symbol table offset */
|
||
// uint32_t nsyms; /* number of symbol table entries */
|
||
// uint32_t stroff; /* string table offset */
|
||
// uint32_t strsize; /* string table size in bytes */
|
||
//};
|
||
|
||
/*
|
||
* This is the symbol table entry structure for 64-bit architectures.
|
||
*/
|
||
struct nlist_64 {
|
||
union {
|
||
uint32_t n_strx; /* index into the string table */ //str_adr=stroff+n_strx
|
||
} n_un;
|
||
uint8_t n_type; /* type flag, see below */
|
||
uint8_t n_sect; /* section number or NO_SECT */
|
||
uint16_t n_desc; /* see <mach-o/stab.h> */
|
||
uint64_t n_value; /* value of this symbol (or stab offset) */
|
||
};
|
||
//samples, str=0x39A9C48
|
||
//25000000 0F060000 940BFF00 80FFFFFF constructors_used , seg=__DATA:__lock_grp
|
||
//2D9D0000 0F170000 00601000 80FFFFFF _BootPDPT __HIB:__text
|
||
//EDCD0000 0F010000 F0729D00 80FFFFFF _IOFlushProcessorCache __TEXT:__text
|
||
//7DE90000 0F150000 B0A6C100 80FFFFFF _KHEAP_AUDIT __DATA_CONST:__mod_init_func
|
||
|
||
/*
|
||
* Symbols with a index into the string table of zero (n_un.n_strx == 0) are
|
||
* defined to have a null, "", name. Therefore all string indexes to non null
|
||
* names must not have a zero string index. This is bit historical information
|
||
* that has never been well documented.
|
||
*/
|
||
|
||
/*
|
||
* The n_type field really contains four fields:
|
||
* unsigned char N_STAB:3,
|
||
* N_PEXT:1,
|
||
* N_TYPE:3,
|
||
* N_EXT:1;
|
||
* which are used via the following masks.
|
||
*/
|
||
#define N_STAB 0xe0 /* if any of these bits set, a symbolic debugging entry */
|
||
#define N_PEXT 0x10 /* private external symbol bit */
|
||
#define N_TYPE 0x0e /* mask for the type bits */
|
||
#define N_EXT 0x01 /* external symbol bit, set for external symbols */
|
||
|
||
/*
|
||
* Only symbolic debugging entries have some of the N_STAB bits set and if any
|
||
* of these bits are set then it is a symbolic debugging entry (a stab). In
|
||
* which case then the values of the n_type field (the entire field) are given
|
||
* in <mach-o/stab.h>
|
||
*/
|
||
/*
|
||
* Symbolic debugger symbols. The comments give the conventional use for
|
||
*
|
||
* .stabs "n_name", n_type, n_sect, n_desc, n_value
|
||
*
|
||
* where n_type is the defined constant and not listed in the comment. Other
|
||
* fields not listed are zero. n_sect is the section ordinal the entry is
|
||
* refering to.
|
||
*/
|
||
#define N_GSYM 0x20 /* global symbol: name,,NO_SECT,type,0 */
|
||
#define N_FNAME 0x22 /* procedure name (f77 kludge): name,,NO_SECT,0,0 */
|
||
#define N_FUN 0x24 /* procedure: name,,n_sect,linenumber,address */
|
||
#define N_STSYM 0x26 /* static symbol: name,,n_sect,type,address */
|
||
#define N_LCSYM 0x28 /* .lcomm symbol: name,,n_sect,type,address */
|
||
#define N_BNSYM 0x2e /* begin nsect sym: 0,,n_sect,0,address */
|
||
#define N_AST 0x32 /* AST file path: name,,NO_SECT,0,0 */
|
||
#define N_OPT 0x3c /* emitted with gcc2_compiled and in gcc source */
|
||
#define N_RSYM 0x40 /* register sym: name,,NO_SECT,type,register */
|
||
#define N_SLINE 0x44 /* src line: 0,,n_sect,linenumber,address */
|
||
#define N_ENSYM 0x4e /* end nsect sym: 0,,n_sect,0,address */
|
||
#define N_SSYM 0x60 /* structure elt: name,,NO_SECT,type,struct_offset */
|
||
#define N_SO 0x64 /* source file name: name,,n_sect,0,address */
|
||
#define N_OSO 0x66 /* object file name: name,,0,0,st_mtime */
|
||
#define N_LSYM 0x80 /* local sym: name,,NO_SECT,type,offset */
|
||
#define N_BINCL 0x82 /* include file beginning: name,,NO_SECT,0,sum */
|
||
#define N_SOL 0x84 /* #included file name: name,,n_sect,0,address */
|
||
#define N_PARAMS 0x86 /* compiler parameters: name,,NO_SECT,0,0 */
|
||
#define N_VERSION 0x88 /* compiler version: name,,NO_SECT,0,0 */
|
||
#define N_OLEVEL 0x8A /* compiler -O level: name,,NO_SECT,0,0 */
|
||
#define N_PSYM 0xa0 /* parameter: name,,NO_SECT,type,offset */
|
||
#define N_EINCL 0xa2 /* include file end: name,,NO_SECT,0,0 */
|
||
#define N_ENTRY 0xa4 /* alternate entry: name,,n_sect,linenumber,address */
|
||
#define N_LBRAC 0xc0 /* left bracket: 0,,NO_SECT,nesting level,address */
|
||
#define N_EXCL 0xc2 /* deleted include file: name,,NO_SECT,0,sum */
|
||
#define N_RBRAC 0xe0 /* right bracket: 0,,NO_SECT,nesting level,address */
|
||
#define N_BCOMM 0xe2 /* begin common: name,,NO_SECT,0,0 */
|
||
#define N_ECOMM 0xe4 /* end common: name,,n_sect,0,0 */
|
||
#define N_ECOML 0xe8 /* end common (local name): 0,,n_sect,0,address */
|
||
#define N_LENG 0xfe /* second stab entry with length information */
|
||
|
||
|
||
/*
|
||
* Values for N_TYPE bits of the n_type field.
|
||
*/
|
||
#define N_UNDF 0x0 /* undefined, n_sect == NO_SECT */
|
||
#define N_ABS 0x2 /* absolute, n_sect == NO_SECT */
|
||
#define N_SECT 0xe /* defined in section number n_sect */
|
||
#define N_PBUD 0xc /* prebound undefined (defined in a dylib) */
|
||
#define N_INDR 0xa /* indirect */
|
||
|
||
/*
|
||
* If the type is N_INDR then the symbol is defined to be the same as another
|
||
* symbol. In this case the n_value field is an index into the string table
|
||
* of the other symbol's name. When the other symbol is defined then they both
|
||
* take on the defined type and value.
|
||
*/
|
||
|
||
/*
|
||
* If the type is N_SECT then the n_sect field contains an ordinal of the
|
||
* section the symbol is defined in. The sections are numbered from 1 and
|
||
* refer to sections in order they appear in the load commands for the file
|
||
* they are in. This means the same ordinal may very well refer to different
|
||
* sections in different files.
|
||
*
|
||
* The n_value field for all symbol table entries (including N_STAB's) gets
|
||
* updated by the link editor based on the value of it's n_sect field and where
|
||
* the section n_sect references gets relocated. If the value of the n_sect
|
||
* field is NO_SECT then it's n_value field is not changed by the link editor.
|
||
*/
|
||
#define NO_SECT 0 /* symbol is not in any section */
|
||
#define MAX_SECT 255 /* 1 thru 255 inclusive */
|
||
|
||
/*
|
||
* Common symbols are represented by undefined (N_UNDF) external (N_EXT) types
|
||
* who's values (n_value) are non-zero. In which case the value of the n_value
|
||
* field is the size (in bytes) of the common symbol. The n_sect field is set
|
||
* to NO_SECT. The alignment of a common symbol may be set as a power of 2
|
||
* between 2^1 and 2^15 as part of the n_desc field using the macros below. If
|
||
* the alignment is not set (a value of zero) then natural alignment based on
|
||
* the size is used.
|
||
*/
|
||
#define GET_COMM_ALIGN(n_desc) (((n_desc) >> 8) & 0x0f)
|
||
#define SET_COMM_ALIGN(n_desc,align) \
|
||
(n_desc) = (((n_desc) & 0xf0ff) | (((align) & 0x0f) << 8))
|
||
|
||
/*
|
||
* To support the lazy binding of undefined symbols in the dynamic link-editor,
|
||
* the undefined symbols in the symbol table (the nlist structures) are marked
|
||
* with the indication if the undefined reference is a lazy reference or
|
||
* non-lazy reference. If both a non-lazy reference and a lazy reference is
|
||
* made to the same symbol the non-lazy reference takes precedence. A reference
|
||
* is lazy only when all references to that symbol are made through a symbol
|
||
* pointer in a lazy symbol pointer section.
|
||
*
|
||
* The implementation of marking nlist structures in the symbol table for
|
||
* undefined symbols will be to use some of the bits of the n_desc field as a
|
||
* reference type. The mask REFERENCE_TYPE will be applied to the n_desc field
|
||
* of an nlist structure for an undefined symbol to determine the type of
|
||
* undefined reference (lazy or non-lazy).
|
||
*
|
||
* The constants for the REFERENCE FLAGS are propagated to the reference table
|
||
* in a shared library file. In that case the constant for a defined symbol,
|
||
* REFERENCE_FLAG_DEFINED, is also used.
|
||
*/
|
||
/* Reference type bits of the n_desc field of undefined symbols */
|
||
#define REFERENCE_TYPE 0x7
|
||
/* types of references */
|
||
#define REFERENCE_FLAG_UNDEFINED_NON_LAZY 0
|
||
#define REFERENCE_FLAG_UNDEFINED_LAZY 1
|
||
#define REFERENCE_FLAG_DEFINED 2
|
||
#define REFERENCE_FLAG_PRIVATE_DEFINED 3
|
||
#define REFERENCE_FLAG_PRIVATE_UNDEFINED_NON_LAZY 4
|
||
#define REFERENCE_FLAG_PRIVATE_UNDEFINED_LAZY 5
|
||
|
||
/*
|
||
* To simplify stripping of objects that use are used with the dynamic link
|
||
* editor, the static link editor marks the symbols defined an object that are
|
||
* referenced by a dynamicly bound object (dynamic shared libraries, bundles).
|
||
* With this marking strip knows not to strip these symbols.
|
||
*/
|
||
#define REFERENCED_DYNAMICALLY 0x0010
|
||
|
||
/*
|
||
* For images created by the static link editor with the -twolevel_namespace
|
||
* option in effect the flags field of the mach header is marked with
|
||
* MH_TWOLEVEL. And the binding of the undefined references of the image are
|
||
* determined by the static link editor. Which library an undefined symbol is
|
||
* bound to is recorded by the static linker in the high 8 bits of the n_desc
|
||
* field using the SET_LIBRARY_ORDINAL macro below. The ordinal recorded
|
||
* references the libraries listed in the Mach-O's LC_LOAD_DYLIB,
|
||
* LC_LOAD_WEAK_DYLIB, LC_REEXPORT_DYLIB, LC_LOAD_UPWARD_DYLIB, and
|
||
* LC_LAZY_LOAD_DYLIB, etc. load commands in the order they appear in the
|
||
* headers. The library ordinals start from 1.
|
||
* For a dynamic library that is built as a two-level namespace image the
|
||
* undefined references from module defined in another use the same nlist struct
|
||
* an in that case SELF_LIBRARY_ORDINAL is used as the library ordinal. For
|
||
* defined symbols in all images they also must have the library ordinal set to
|
||
* SELF_LIBRARY_ORDINAL. The EXECUTABLE_ORDINAL refers to the executable
|
||
* image for references from plugins that refer to the executable that loads
|
||
* them.
|
||
*
|
||
* The DYNAMIC_LOOKUP_ORDINAL is for undefined symbols in a two-level namespace
|
||
* image that are looked up by the dynamic linker with flat namespace semantics.
|
||
* This ordinal was added as a feature in Mac OS X 10.3 by reducing the
|
||
* value of MAX_LIBRARY_ORDINAL by one. So it is legal for existing binaries
|
||
* or binaries built with older tools to have 0xfe (254) dynamic libraries. In
|
||
* this case the ordinal value 0xfe (254) must be treated as a library ordinal
|
||
* for compatibility.
|
||
*/
|
||
#define GET_LIBRARY_ORDINAL(n_desc) (((n_desc) >> 8) & 0xff)
|
||
#define SET_LIBRARY_ORDINAL(n_desc,ordinal) \
|
||
(n_desc) = (((n_desc) & 0x00ff) | (((ordinal) & 0xff) << 8))
|
||
#define SELF_LIBRARY_ORDINAL 0x0
|
||
#define MAX_LIBRARY_ORDINAL 0xfd
|
||
#define DYNAMIC_LOOKUP_ORDINAL 0xfe
|
||
#define EXECUTABLE_ORDINAL 0xff
|
||
|
||
/*
|
||
* The bit 0x0020 of the n_desc field is used for two non-overlapping purposes
|
||
* and has two different symbolic names, N_NO_DEAD_STRIP and N_DESC_DISCARDED.
|
||
*/
|
||
|
||
/*
|
||
* The N_NO_DEAD_STRIP bit of the n_desc field only ever appears in a
|
||
* relocatable .o file (MH_OBJECT filetype). And is used to indicate to the
|
||
* static link editor it is never to dead strip the symbol.
|
||
*/
|
||
#define N_NO_DEAD_STRIP 0x0020 /* symbol is not to be dead stripped */
|
||
|
||
/*
|
||
* The N_DESC_DISCARDED bit of the n_desc field never appears in linked image.
|
||
* But is used in very rare cases by the dynamic link editor to mark an in
|
||
* memory symbol as discared and longer used for linking.
|
||
*/
|
||
#define N_DESC_DISCARDED 0x0020 /* symbol is discarded */
|
||
|
||
/*
|
||
* The N_WEAK_REF bit of the n_desc field indicates to the dynamic linker that
|
||
* the undefined symbol is allowed to be missing and is to have the address of
|
||
* zero when missing.
|
||
*/
|
||
#define N_WEAK_REF 0x0040 /* symbol is weak referenced */
|
||
|
||
/*
|
||
* The N_WEAK_DEF bit of the n_desc field indicates to the static and dynamic
|
||
* linkers that the symbol definition is weak, allowing a non-weak symbol to
|
||
* also be used which causes the weak definition to be discared. Currently this
|
||
* is only supported for symbols in coalesed sections.
|
||
*/
|
||
#define N_WEAK_DEF 0x0080 /* coalesed symbol is a weak definition */
|
||
|
||
/*
|
||
* The N_REF_TO_WEAK bit of the n_desc field indicates to the dynamic linker
|
||
* that the undefined symbol should be resolved using flat namespace searching.
|
||
*/
|
||
#define N_REF_TO_WEAK 0x0080 /* reference to a weak symbol */
|
||
|
||
/*
|
||
* The N_ARM_THUMB_DEF bit of the n_desc field indicates that the symbol is
|
||
* a defintion of a Thumb function.
|
||
*/
|
||
#define N_ARM_THUMB_DEF 0x0008 /* symbol is a Thumb function (ARM) */
|
||
|
||
/*
|
||
* The N_SYMBOL_RESOLVER bit of the n_desc field indicates that the
|
||
* that the function is actually a resolver function and should
|
||
* be called to get the address of the real function to use.
|
||
* This bit is only available in .o files (MH_OBJECT filetype)
|
||
*/
|
||
#define N_SYMBOL_RESOLVER 0x0100
|
||
|
||
/*
|
||
* The N_ALT_ENTRY bit of the n_desc field indicates that the
|
||
* symbol is pinned to the previous content.
|
||
*/
|
||
#define N_ALT_ENTRY 0x0200
|
||
|
||
|
||
#endif /* _MACHO_LOADER_H_ */
|