Magic number (programming) – Wikipedia, the free encyclopedia


Interesting list of “Magic Debug Values” from Wikipedia:

  • 0x..FACADE : Used by a number of RTOSes
  • 0xA5A5A5A5 : Used in embedded development because the alternating bit pattern (10100101) creates an easily recognized pattern on oscilloscopes and logic analyzers.
  • 0xABABABAB : Used by Microsoft‘s HeapAlloc() to mark “no man’s land” guard bytes after allocated heap memory
  • 0xABADBABE : Used by Apple as the “Boot Zero Block” magic number
  • 0xABADCAFE : A startup to this value to initialize all free memory to catch errant pointers
  • 0xBAADF00D : Used by Microsoft‘s LocalAlloc(LMEM_FIXED) to mark uninitialised allocated heap memory
  • 0xBADBADBADBAD : Burroughs large systems “uninitialized” memory (48-bit words)
  • 0xBADCAB1E : Error Code returned to the Microsoft eVC debugger when connection is severed to the debugger
  • 0xBADC0FFEE0DDF00D : Used on IBM RS/6000 64-bit systems to indicate uninitialized CPU registers
  • 0xBADDCAFE : On Sun MicrosystemsSolaris, marks uninitialised kernel memory (KMEM_UNINITIALIZED_PATTERN)
  • 0xBEEFCACE : Used by Microsoft .NET as a magic number in resource files
  • 0xC0DEDBAD : A memory leak tracking tool which it will change the MMU tables so that all references to address zero
  • 0xCAFEBABE : Used by both Mach-O (“Fat binary” in both 68k and PowerPC) to identify object files and the Java programming language to identify .class files
  • 0xCAFEFEED : Used by Sun MicrosystemsSolaris debugging kernel to mark kmemfree() memory
  • 0xCEFAEDFE : Seen in Intel Mach-O binaries on Apple Computer‘s Mac OS X platform (see 0xFEEDFACE below)
  • 0xCCCCCCCC : Used by Microsoft‘s C++ debugging runtime library to mark uninitialised stack memory
  • 0xCDCDCDCD : Used by Microsoft‘s C++ debugging runtime library to mark uninitialised heap memory
  • 0xDDDDDDDD : Used by MicroQuill’s SmartHeap and Microsoft’s C++ debugging heap to mark freed heap memory
  • 0xDEADBABE : Used at the start of Silicon GraphicsIRIX arena files
  • 0xDEADBEEF : Famously used on IBM systems such as the RS/6000, also used in the original Mac OS operating systems, OPENSTEP Enterprise, and the Commodore Amiga. On Sun MicrosystemsSolaris, marks freed kernel memory (KMEM_FREE_PATTERN)
  • 0xDEADDEAD : A Microsoft Windows STOP Error code used when the user manually initiates the crash.
  • 0xDEADF00D : All the newly allocated memory which is not explicitly cleared when it is munged
  • 0xEBEBEBEB : From MicroQuill’s SmartHeap
  • 0xFADEDEAD : Comes at the end to identify every OSA script
  • 0xFDFDFDFD : Used by Microsoft‘s C++ debugging heap to mark “no man’s land” guard bytes before and after allocated heap memory
  • 0xFEEDFACE : Seen in PowerPC Mach-O binaries on Apple Computer‘s Mac OS X platform. On Sun MicrosystemsSolaris, marks the red zone (KMEM_REDZONE_PATTERN)
  • 0xFEEEFEEE : Used by Microsoft‘s HeapFree() to mark freed heap memory
  • 0xFEE1DEAD : Used by Linux reboot() syscall

via Magic number (programming) – Wikipedia, the free encyclopedia

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