mach-binary = mach-header load-command* data
mach-header = magic cputype filetype ncmds sizeofcmds flags
load-command = cmdtype cmdsize (segment-command | dylib-command | symtab-command | dysymtab-command | dyld-info-command | ...)
struct load_command { uint32_t cmd; uint32_t cmdsize; union { struct segment_command; struct dylib_command; ... } };
Some load commands refer the data