http://clang.llvm.org/docs/Block-ABI-Apple.html

Syscall flavors */

* 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 in

* This is the second set of the symbolic information which is used to support * the data structures for the dynamically link editor. * * The origin

* The entry_point_command is a replacement for thread_command. * It is used for main executables to specify the location (file offset) * of main().

* The load commands directly follow the mach_header. The total size of all * of the commands is given by the sizeofcmds field in the mach_header. Al

* The 64-bit mach header appears at the very beginning of object files for * 64-bit architectures. */

* This is the symbol table entry structure for 64-bit architectures. */