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 Microsystems‘ Solaris, 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 Microsystems‘ Solaris 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 Graphics‘ IRIX 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 Microsystems‘ Solaris, 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 Microsystems‘ Solaris, 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