/*
* Copyright (c) 1999-2008 Apple Inc. All Rights Reserved.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. The rights granted to you under the License
- * may not be used to create, or enable the creation or redistribution of,
- * unlawful or unlicensed copies of an Apple operating system, or to
- * circumvent, violate, or enable the circumvention or violation of, any
- * terms of an Apple operating system software license agreement.
- *
- * Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* Please see the License for the specific language governing rights and
* limitations under the License.
*
- * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ * @APPLE_LICENSE_HEADER_END@
*/
#ifndef _MACHO_LOADER_H_
#define _MACHO_LOADER_H_
* states and the structures of those flavors for each machine.
*/
#include <mach/machine/thread_status.h>
-#ifndef KERNEL
#include <architecture/byte_order.h>
-#endif /* KERNEL */
/*
* The 32-bit mach header appears at the very beginning of the object file for
/* linking only, no section contents */
#define MH_DSYM 0xa /* companion file with only debug */
/* sections */
+#define MH_KEXT_BUNDLE 0xb /* x86_64 kexts */
/* Constants for the flags field of the mach_header */
#define MH_NOUNDEFS 0x1 /* the object file has no undefined
in the task will be given stack
execution privilege. Only used in
MH_EXECUTE filetypes. */
+#define MH_DEAD_STRIPPABLE_DYLIB 0x400000 /* Only for use on dylibs. When
+ linking against a dylib that
+ has this bit set, the static linker
+ will automatically not create a
+ LC_LOAD_DYLIB load command to the
+ dylib if no symbols are being
+ referenced from the dylib. */
#define MH_ROOT_SAFE 0x40000 /* When this bit is set, the binary
declares it is safe for use in
processes with uid zero */
load the main executable at a
random address. Only used in
MH_EXECUTE filetypes. */
+#define MH_NO_HEAP_EXECUTION 0x1000000 /* When this bit is set, the OS will
+ run the main executable with
+ a non-executable heap even on
+ platforms (e.g. i386) that don't
+ require it. Only used in MH_EXECUTE
+ filetypes. */
/*
* The load commands directly follow the mach_header. The total size of all
#define LC_REEXPORT_DYLIB (0x1f | LC_REQ_DYLD) /* load and re-export dylib */
#define LC_LAZY_LOAD_DYLIB 0x20 /* delay load of dylib until first use */
#define LC_ENCRYPTION_INFO 0x21 /* encrypted segment information */
+#define LC_DYLD_INFO 0x22 /* compressed dyld information */
+#define LC_DYLD_INFO_ONLY (0x22|LC_REQ_DYLD) /* compressed dyld information only */
/*
* A variable length string in a load command is represented by an lc_str
0 means not-encrypted yet */
};
+/*
+ * 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 rebase 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 byte that is the length of
+ * the exported symbol information for the string so far.
+ * If there is no exported symbol, the byte is zero. If there
+ * is exported info, it follows the length byte. The exported
+ * info normally consists of a flags and offset both encoded
+ * in uleb128. The offset is location of the content named
+ * by the symbol. It is the offset from the mach_header for
+ * the image.
+ *
+ * After the initial byte and 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 cstring 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
+
+
+/*
+ * 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_INDIRECT_DEFINITION 0x08
+#define EXPORT_SYMBOL_FLAGS_HAS_SPECIALIZATIONS 0x10
+
/*
* The symseg_command contains the offset and size of the GNU style
* symbol table information as described in the header file <symseg.h>.
projects / apple / xnu.git / blobdiff