fs/Kconfig.binfmt

   1 # SPDX-License-Identifier: GPL-2.0-only
   2
   3 menu "Executable file formats"
   4
   5 config BINFMT_ELF
   6         bool "Kernel support for ELF binaries"
   7         depends on MMU
   8         select ELFCORE
   9         default y
  10         ---help---
  11           ELF (Executable and Linkable Format) is a format for libraries and
  12           executables used across different architectures and operating
  13           systems. Saying Y here will enable your kernel to run ELF binaries
  14           and enlarge it by about 13 KB. ELF support under Linux has now all
  15           but replaced the traditional Linux a.out formats (QMAGIC and ZMAGIC)
  16           because it is portable (this does *not* mean that you will be able
  17           to run executables from different architectures or operating systems
  18           however) and makes building run-time libraries very easy. Many new
  19           executables are distributed solely in ELF format. You definitely
  20           want to say Y here.
  21
  22           Information about ELF is contained in the ELF HOWTO available from
  23           <http://www.tldp.org/docs.html#howto>.
  24
  25           If you find that after upgrading from Linux kernel 1.2 and saying Y
  26           here, you still can't run any ELF binaries (they just crash), then
  27           you'll have to install the newest ELF runtime libraries, including
  28           ld.so (check the file <file:Documentation/Changes> for location and
  29           latest version).
  30
  31 config COMPAT_BINFMT_ELF
  32         bool
  33         depends on COMPAT && BINFMT_ELF
  34         select ELFCORE
  35
  36 config ARCH_BINFMT_ELF_STATE
  37         bool
  38
  39 config BINFMT_ELF_FDPIC
  40         bool "Kernel support for FDPIC ELF binaries"
  41         default y if !BINFMT_ELF
  42         depends on (ARM || (SUPERH32 && !MMU) || C6X)
  43         select ELFCORE
  44         help
  45           ELF FDPIC binaries are based on ELF, but allow the individual load
  46           segments of a binary to be located in memory independently of each
  47           other. This makes this format ideal for use in environments where no
  48           MMU is available as it still permits text segments to be shared,
  49           even if data segments are not.
  50
  51           It is also possible to run FDPIC ELF binaries on MMU linux also.
  52
  53 config ELFCORE
  54         bool
  55         help
  56           This option enables kernel/elfcore.o.
  57
  58 config CORE_DUMP_DEFAULT_ELF_HEADERS
  59         bool "Write ELF core dumps with partial segments"
  60         default y
  61         depends on BINFMT_ELF && ELF_CORE
  62         help
  63           ELF core dump files describe each memory mapping of the crashed
  64           process, and can contain or omit the memory contents of each one.
  65           The contents of an unmodified text mapping are omitted by default.
  66
  67           For an unmodified text mapping of an ELF object, including just
  68           the first page of the file in a core dump makes it possible to
  69           identify the build ID bits in the file, without paying the i/o
  70           cost and disk space to dump all the text.  However, versions of
  71           GDB before 6.7 are confused by ELF core dump files in this format.
  72
  73           The core dump behavior can be controlled per process using
  74           the /proc/PID/coredump_filter pseudo-file; this setting is
  75           inherited.  See Documentation/filesystems/proc.txt for details.
  76
  77           This config option changes the default setting of coredump_filter
  78           seen at boot time.  If unsure, say Y.
  79
  80 config BINFMT_SCRIPT
  81         tristate "Kernel support for scripts starting with #!"
  82         default y
  83         help
  84           Say Y here if you want to execute interpreted scripts starting with
  85           #! followed by the path to an interpreter.
  86
  87           You can build this support as a module; however, until that module
  88           gets loaded, you cannot run scripts.  Thus, if you want to load this
  89           module from an initramfs, the portion of the initramfs before loading
  90           this module must consist of compiled binaries only.
  91
  92           Most systems will not boot if you say M or N here.  If unsure, say Y.
  93
  94 config BINFMT_FLAT
  95         bool "Kernel support for flat binaries"
  96         depends on !MMU || ARM || M68K
  97         help
  98           Support uClinux FLAT format binaries.
  99
 100 config BINFMT_ZFLAT
 101         bool "Enable ZFLAT support"
 102         depends on BINFMT_FLAT
 103         select ZLIB_INFLATE
 104         help
 105           Support FLAT format compressed binaries
 106
 107 config BINFMT_SHARED_FLAT
 108         bool "Enable shared FLAT support"
 109         depends on BINFMT_FLAT
 110         help
 111           Support FLAT shared libraries
 112
 113 config HAVE_AOUT
 114        def_bool n
 115
 116 config BINFMT_AOUT
 117         tristate "Kernel support for a.out and ECOFF binaries"
 118         depends on HAVE_AOUT
 119         ---help---
 120           A.out (Assembler.OUTput) is a set of formats for libraries and
 121           executables used in the earliest versions of UNIX.  Linux used
 122           the a.out formats QMAGIC and ZMAGIC until they were replaced
 123           with the ELF format.
 124
 125           The conversion to ELF started in 1995.  This option is primarily
 126           provided for historical interest and for the benefit of those
 127           who need to run binaries from that era.
 128
 129           Most people should answer N here.  If you think you may have
 130           occasional use for this format, enable module support above
 131           and answer M here to compile this support as a module called
 132           binfmt_aout.
 133
 134           If any crucial components of your system (such as /sbin/init
 135           or /lib/ld.so) are still in a.out format, you will have to
 136           say Y here.
 137
 138 config OSF4_COMPAT
 139         bool "OSF/1 v4 readv/writev compatibility"
 140         depends on ALPHA && BINFMT_AOUT
 141         help
 142           Say Y if you are using OSF/1 binaries (like Netscape and Acrobat)
 143           with v4 shared libraries freely available from Compaq. If you're
 144           going to use shared libraries from Tru64 version 5.0 or later, say N.
 145
 146 config BINFMT_EM86
 147         tristate "Kernel support for Linux/Intel ELF binaries"
 148         depends on ALPHA
 149         ---help---
 150           Say Y here if you want to be able to execute Linux/Intel ELF
 151           binaries just like native Alpha binaries on your Alpha machine. For
 152           this to work, you need to have the emulator /usr/bin/em86 in place.
 153
 154           You can get the same functionality by saying N here and saying Y to
 155           "Kernel support for MISC binaries".
 156
 157           You may answer M to compile the emulation support as a module and
 158           later load the module when you want to use a Linux/Intel binary. The
 159           module will be called binfmt_em86. If unsure, say Y.
 160
 161 config BINFMT_MISC
 162         tristate "Kernel support for MISC binaries"
 163         ---help---
 164           If you say Y here, it will be possible to plug wrapper-driven binary
 165           formats into the kernel. You will like this especially when you use
 166           programs that need an interpreter to run like Java, Python, .NET or
 167           Emacs-Lisp. It's also useful if you often run DOS executables under
 168           the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO, available from
 169           <http://www.tldp.org/docs.html#howto>). Once you have
 170           registered such a binary class with the kernel, you can start one of
 171           those programs simply by typing in its name at a shell prompt; Linux
 172           will automatically feed it to the correct interpreter.
 173
 174           You can do other nice things, too. Read the file
 175           <file:Documentation/admin-guide/binfmt-misc.rst> to learn how to use this
 176           feature, <file:Documentation/admin-guide/java.rst> for information about how
 177           to include Java support. and <file:Documentation/admin-guide/mono.rst> for
 178           information about how to include Mono-based .NET support.
 179
 180           To use binfmt_misc, you will need to mount it:
 181                 mount binfmt_misc -t binfmt_misc /proc/sys/fs/binfmt_misc
 182
 183           You may say M here for module support and later load the module when
 184           you have use for it; the module is called binfmt_misc. If you
 185           don't know what to answer at this point, say Y.
 186
 187 config COREDUMP
 188         bool "Enable core dump support" if EXPERT
 189         default y
 190         help
 191           This option enables support for performing core dumps. You almost
 192           certainly want to say Y here. Not necessary on systems that never
 193           need debugging or only ever run flawless code.
 194
 195 endmenu