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 ARCH_HAVE_ELF_PROT
  40         bool
  41
  42 config ARCH_USE_GNU_PROPERTY
  43         bool
  44
  45 config BINFMT_ELF_FDPIC
  46         bool "Kernel support for FDPIC ELF binaries"
  47         default y if !BINFMT_ELF
  48         depends on (ARM || (SUPERH && !MMU) || C6X)
  49         select ELFCORE
  50         help
  51           ELF FDPIC binaries are based on ELF, but allow the individual load
  52           segments of a binary to be located in memory independently of each
  53           other. This makes this format ideal for use in environments where no
  54           MMU is available as it still permits text segments to be shared,
  55           even if data segments are not.
  56
  57           It is also possible to run FDPIC ELF binaries on MMU linux also.
  58
  59 config ELFCORE
  60         bool
  61         help
  62           This option enables kernel/elfcore.o.
  63
  64 config CORE_DUMP_DEFAULT_ELF_HEADERS
  65         bool "Write ELF core dumps with partial segments"
  66         default y
  67         depends on BINFMT_ELF && ELF_CORE
  68         help
  69           ELF core dump files describe each memory mapping of the crashed
  70           process, and can contain or omit the memory contents of each one.
  71           The contents of an unmodified text mapping are omitted by default.
  72
  73           For an unmodified text mapping of an ELF object, including just
  74           the first page of the file in a core dump makes it possible to
  75           identify the build ID bits in the file, without paying the i/o
  76           cost and disk space to dump all the text.  However, versions of
  77           GDB before 6.7 are confused by ELF core dump files in this format.
  78
  79           The core dump behavior can be controlled per process using
  80           the /proc/PID/coredump_filter pseudo-file; this setting is
  81           inherited.  See Documentation/filesystems/proc.rst for details.
  82
  83           This config option changes the default setting of coredump_filter
  84           seen at boot time.  If unsure, say Y.
  85
  86 config BINFMT_SCRIPT
  87         tristate "Kernel support for scripts starting with #!"
  88         default y
  89         help
  90           Say Y here if you want to execute interpreted scripts starting with
  91           #! followed by the path to an interpreter.
  92
  93           You can build this support as a module; however, until that module
  94           gets loaded, you cannot run scripts.  Thus, if you want to load this
  95           module from an initramfs, the portion of the initramfs before loading
  96           this module must consist of compiled binaries only.
  97
  98           Most systems will not boot if you say M or N here.  If unsure, say Y.
  99
 100 config ARCH_HAS_BINFMT_FLAT
 101         bool
 102
 103 config BINFMT_FLAT
 104         bool "Kernel support for flat binaries"
 105         depends on ARCH_HAS_BINFMT_FLAT
 106         help
 107           Support uClinux FLAT format binaries.
 108
 109 config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
 110         bool
 111
 112 config BINFMT_FLAT_OLD_ALWAYS_RAM
 113         bool
 114
 115 config BINFMT_FLAT_OLD
 116         bool "Enable support for very old legacy flat binaries"
 117         depends on BINFMT_FLAT
 118         help
 119           Support decade old uClinux FLAT format binaries.  Unless you know
 120           you have some of those say N here.
 121
 122 config BINFMT_ZFLAT
 123         bool "Enable ZFLAT support"
 124         depends on BINFMT_FLAT
 125         select ZLIB_INFLATE
 126         help
 127           Support FLAT format compressed binaries
 128
 129 config BINFMT_SHARED_FLAT
 130         bool "Enable shared FLAT support"
 131         depends on BINFMT_FLAT
 132         help
 133           Support FLAT shared libraries
 134
 135 config HAVE_AOUT
 136        def_bool n
 137
 138 config BINFMT_AOUT
 139         tristate "Kernel support for a.out and ECOFF binaries"
 140         depends on HAVE_AOUT
 141         help
 142           A.out (Assembler.OUTput) is a set of formats for libraries and
 143           executables used in the earliest versions of UNIX.  Linux used
 144           the a.out formats QMAGIC and ZMAGIC until they were replaced
 145           with the ELF format.
 146
 147           The conversion to ELF started in 1995.  This option is primarily
 148           provided for historical interest and for the benefit of those
 149           who need to run binaries from that era.
 150
 151           Most people should answer N here.  If you think you may have
 152           occasional use for this format, enable module support above
 153           and answer M here to compile this support as a module called
 154           binfmt_aout.
 155
 156           If any crucial components of your system (such as /sbin/init
 157           or /lib/ld.so) are still in a.out format, you will have to
 158           say Y here.
 159
 160 config OSF4_COMPAT
 161         bool "OSF/1 v4 readv/writev compatibility"
 162         depends on ALPHA && BINFMT_AOUT
 163         help
 164           Say Y if you are using OSF/1 binaries (like Netscape and Acrobat)
 165           with v4 shared libraries freely available from Compaq. If you're
 166           going to use shared libraries from Tru64 version 5.0 or later, say N.
 167
 168 config BINFMT_EM86
 169         tristate "Kernel support for Linux/Intel ELF binaries"
 170         depends on ALPHA
 171         help
 172           Say Y here if you want to be able to execute Linux/Intel ELF
 173           binaries just like native Alpha binaries on your Alpha machine. For
 174           this to work, you need to have the emulator /usr/bin/em86 in place.
 175
 176           You can get the same functionality by saying N here and saying Y to
 177           "Kernel support for MISC binaries".
 178
 179           You may answer M to compile the emulation support as a module and
 180           later load the module when you want to use a Linux/Intel binary. The
 181           module will be called binfmt_em86. If unsure, say Y.
 182
 183 config BINFMT_MISC
 184         tristate "Kernel support for MISC binaries"
 185         help
 186           If you say Y here, it will be possible to plug wrapper-driven binary
 187           formats into the kernel. You will like this especially when you use
 188           programs that need an interpreter to run like Java, Python, .NET or
 189           Emacs-Lisp. It's also useful if you often run DOS executables under
 190           the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO, available from
 191           <http://www.tldp.org/docs.html#howto>). Once you have
 192           registered such a binary class with the kernel, you can start one of
 193           those programs simply by typing in its name at a shell prompt; Linux
 194           will automatically feed it to the correct interpreter.
 195
 196           You can do other nice things, too. Read the file
 197           <file:Documentation/admin-guide/binfmt-misc.rst> to learn how to use this
 198           feature, <file:Documentation/admin-guide/java.rst> for information about how
 199           to include Java support. and <file:Documentation/admin-guide/mono.rst> for
 200           information about how to include Mono-based .NET support.
 201
 202           To use binfmt_misc, you will need to mount it:
 203                 mount binfmt_misc -t binfmt_misc /proc/sys/fs/binfmt_misc
 204
 205           You may say M here for module support and later load the module when
 206           you have use for it; the module is called binfmt_misc. If you
 207           don't know what to answer at this point, say Y.
 208
 209 config COREDUMP
 210         bool "Enable core dump support" if EXPERT
 211         default y
 212         help
 213           This option enables support for performing core dumps. You almost
 214           certainly want to say Y here. Not necessary on systems that never
 215           need debugging or only ever run flawless code.
 216
 217 endmenu