Difference between revisions of "Hexspeak"

Revision as of 11:40, 3 September 2014

Notable magic numbers

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Many computer processors, operating systems, and debuggers make use of magic numbers, especially as a magic debug value.

• 0x0000000FF1CE ("office") is used as the last part of product codes (guid) for Microsoft Office components (visible in registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall registry key).
• 0x00BAB10C ("über (ooba) block") is used as the magic number for the ZFS uberblock.
• 0x8BADF00D ("ate bad food") is used by Apple in iOS crash reports, when an application takes too long to launch, terminate, or respond to system events.^[1]
• 0x1BADB002 ("1 bad boot"^[2]) Multiboot header magic number.^[3]
• 0x1CEB00DA ("ice buddha") was used as the origin for the binary file parser IceBuddha.^[4]
• 0xB105F00D ("BIOS food") is the value of the low bytes of last four registers on ARM PrimeCell compatible components (the component_id registers), used to identify correct behaviour of a memory-mapped component.
• 0xB16B00B5 ("big boobs") was required by Microsoft's Hyper-V hypervisor to be used by Linux guests as their "guest signature".^[5] One proposal suggested changing it to 0x0DEFACED ("defaced").^[6] Actually, it was initially changed to decimal and then replaced entirely.^[7]
• 0xBAADF00D ("bad food") is used by Microsoft's LocalAlloc(LMEM_FIXED) to indicate uninitialised allocated heap memory when the debug heap is used.^[8]
• 0xBADDCAFE ("bad cafe") is used by Libumem to indicate uninitialized memory area
• C15C:0D06:F00D ("cisco dog food") used in the IPv6 address of www.cisco.com on World IPv6 Day. "Dog food" refers to Cisco eating its own dog food with IPv6.
• 0xCAFEBABE ("cafe babe") is used by Mach-O to identify Universal object files, and by the Java programming language to identify Java bytecode class files.^[9]
• 0xCAFED00D ("cafe dude") is used by Java as a magic number for their pack200 compression.^[10]
• 0xCEFAEDFE ("face feed") is used by Mach-O to identify flat (single architecture) object files. In little endian this reads FEEDFACE, "Feed Face".
• 0xD15EA5E ("disease") is a flag that indicates regular boot on the Nintendo GameCube and Wii consoles.^[11][12]
• 0xDABBAD00 ("dabba doo") is the name of a blog on computer security.^[13]
• 0xDEADBABE ("Dead Babe") is used by IBM Jikes RVM as a sanity check of the stack of the primary thread.^[14]
• 0xDEADBEAF ("dead beaf") is part of the signature code of Jazz Jackrabbit 2 tileset files.^[15] Level files have less room for their signatures and use 0xBABE ("babe") instead.^[16] It is also the header of campaign gamesaves used in the Halo Game Series.
• 0xDEADBEEF ("dead beef") is frequently used to indicate a software crash or deadlock in embedded systems. DEADBEEF was originally used to mark newly allocated areas of memory that had not yet been initialized—when scanning a memory dump, it is easy to see the DEADBEEF. It is used by IBM RS/6000 systems, Mac OS on 32-bit PowerPC processors and the Commodore Amiga as a magic debug value. On Sun Microsystems' Solaris, it marks freed kernel memory. On OpenVMS running on Alpha processors, DEAD_BEEF can be seen by pressing CTRL-T. The DEC Alpha SRM console has a background process that traps memory errors, identified by PS as "BeefEater waiting on 0xdeadbeef".^[17]
• 0xDEADC0DE ("dead code") is used as a marker in OpenWrt firmware to signify the beginning of the to-be created jffs2 filesystem at the end of the static firmware.
• 0xDEADDEAD ("dead dead") is the bug check (STOP) code displayed when invoking a Blue Screen of Death either by telling the kernel via the attached debugger, or by using a special keystroke combination.^[18] This is usually seen by driver developers, as it is used to get a memory dump on Windows NT based systems. An alternative to 0xDEADDEAD is the bug check code 0x000000E2,^[19] as they are both called MANUALLY_INITIATED_CRASH as seen on the Microsoft Developer Network.
• 0xDEADD00D ("dead dude") is used by Android in the Dalvik virtual machine to indicate a VM abort.
• 0xDEADFA11 ("dead fall") is used by Apple in iOS crash reports, when the user force quits an application.^[1]
• 0xDEAD10CC ("dead lock") is used by Apple in iOS crash reports, when application holds on to a system resource while running in the background.^[1]
• 0xDEADFEED ("dead feed") is used by Apple in iOS crash reports, when a timeout occurs spawning a service
• 0xDEFEC8ED ("defecated") is the magic number for OpenSolaris core dumps.^[20]
• 0xE011CFD0 is used as a magic number for Microsoft Office files. In little endian this reads D0CF11E0, "docfile0".^[21]
• face:b00c ("facebook") used in the IPv6 address of www.v6.facebook.com
• 0xFACEFEED ("face feed") is used by Alpha servers running Windows NT. The Alpha Hardware Abstraction Layer (HAL) generates this error when it encounters a hardware failure.^[22]
• 0xFBADBEEF ("bad beef") is used in the WebKit and Blink layout engines to indicate a known, unrecoverable error such as out of memory.^[23]
• 0xFEE1DEAD ("feel dead") is used as a magic number in the Linux reboot system call.^[24]
• 0xDEADBAAD ("dead bad") is used by the Android libc abort() function when native heap corruption is detected.
• deadbeef-dead-beef-dead-beef00000075("dead beef") is the GUID assigned to hung/dead virtual machines in Citrix Xenserver.
• 0x4B1D ("Forbid'den'") was a password in some calibration consoles for developers to peer deeper into control registers outside the normal calibration memory range.