1 # SPDX-License-Identifier: GPL-2.0-only
3 menu "Executable file formats"
6 bool "Kernel support for ELF binaries"
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
22 Information about ELF is contained in the ELF HOWTO available from
23 <http://www.tldp.org/docs.html#howto>.
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
31 config COMPAT_BINFMT_ELF
33 depends on COMPAT && BINFMT_ELF
36 config ARCH_BINFMT_ELF_STATE
39 config ARCH_BINFMT_ELF_EXTRA_PHDRS
42 config ARCH_HAVE_ELF_PROT
45 config ARCH_USE_GNU_PROPERTY
48 config BINFMT_ELF_FDPIC
49 bool "Kernel support for FDPIC ELF binaries"
50 default y if !BINFMT_ELF
51 depends on (ARM || (SUPERH && !MMU))
54 ELF FDPIC binaries are based on ELF, but allow the individual load
55 segments of a binary to be located in memory independently of each
56 other. This makes this format ideal for use in environments where no
57 MMU is available as it still permits text segments to be shared,
58 even if data segments are not.
60 It is also possible to run FDPIC ELF binaries on MMU linux also.
65 This option enables kernel/elfcore.o.
67 config CORE_DUMP_DEFAULT_ELF_HEADERS
68 bool "Write ELF core dumps with partial segments"
70 depends on BINFMT_ELF && ELF_CORE
72 ELF core dump files describe each memory mapping of the crashed
73 process, and can contain or omit the memory contents of each one.
74 The contents of an unmodified text mapping are omitted by default.
76 For an unmodified text mapping of an ELF object, including just
77 the first page of the file in a core dump makes it possible to
78 identify the build ID bits in the file, without paying the i/o
79 cost and disk space to dump all the text. However, versions of
80 GDB before 6.7 are confused by ELF core dump files in this format.
82 The core dump behavior can be controlled per process using
83 the /proc/PID/coredump_filter pseudo-file; this setting is
84 inherited. See Documentation/filesystems/proc.rst for details.
86 This config option changes the default setting of coredump_filter
87 seen at boot time. If unsure, say Y.
90 tristate "Kernel support for scripts starting with #!"
93 Say Y here if you want to execute interpreted scripts starting with
94 #! followed by the path to an interpreter.
96 You can build this support as a module; however, until that module
97 gets loaded, you cannot run scripts. Thus, if you want to load this
98 module from an initramfs, the portion of the initramfs before loading
99 this module must consist of compiled binaries only.
101 Most systems will not boot if you say M or N here. If unsure, say Y.
103 config ARCH_HAS_BINFMT_FLAT
107 bool "Kernel support for flat binaries"
108 depends on ARCH_HAS_BINFMT_FLAT
110 Support uClinux FLAT format binaries.
112 config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
115 config BINFMT_FLAT_OLD_ALWAYS_RAM
118 config BINFMT_FLAT_NO_DATA_START_OFFSET
121 config BINFMT_FLAT_OLD
122 bool "Enable support for very old legacy flat binaries"
123 depends on BINFMT_FLAT
125 Support decade old uClinux FLAT format binaries. Unless you know
126 you have some of those say N here.
129 bool "Enable ZFLAT support"
130 depends on BINFMT_FLAT
133 Support FLAT format compressed binaries
135 config BINFMT_SHARED_FLAT
136 bool "Enable shared FLAT support"
137 depends on BINFMT_FLAT
139 Support FLAT shared libraries
145 tristate "Kernel support for a.out and ECOFF binaries"
148 A.out (Assembler.OUTput) is a set of formats for libraries and
149 executables used in the earliest versions of UNIX. Linux used
150 the a.out formats QMAGIC and ZMAGIC until they were replaced
153 The conversion to ELF started in 1995. This option is primarily
154 provided for historical interest and for the benefit of those
155 who need to run binaries from that era.
157 Most people should answer N here. If you think you may have
158 occasional use for this format, enable module support above
159 and answer M here to compile this support as a module called
162 If any crucial components of your system (such as /sbin/init
163 or /lib/ld.so) are still in a.out format, you will have to
167 bool "OSF/1 v4 readv/writev compatibility"
168 depends on ALPHA && BINFMT_AOUT
170 Say Y if you are using OSF/1 binaries (like Netscape and Acrobat)
171 with v4 shared libraries freely available from Compaq. If you're
172 going to use shared libraries from Tru64 version 5.0 or later, say N.
175 tristate "Kernel support for MISC binaries"
177 If you say Y here, it will be possible to plug wrapper-driven binary
178 formats into the kernel. You will like this especially when you use
179 programs that need an interpreter to run like Java, Python, .NET or
180 Emacs-Lisp. It's also useful if you often run DOS executables under
181 the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO, available from
182 <http://www.tldp.org/docs.html#howto>). Once you have
183 registered such a binary class with the kernel, you can start one of
184 those programs simply by typing in its name at a shell prompt; Linux
185 will automatically feed it to the correct interpreter.
187 You can do other nice things, too. Read the file
188 <file:Documentation/admin-guide/binfmt-misc.rst> to learn how to use this
189 feature, <file:Documentation/admin-guide/java.rst> for information about how
190 to include Java support. and <file:Documentation/admin-guide/mono.rst> for
191 information about how to include Mono-based .NET support.
193 To use binfmt_misc, you will need to mount it:
194 mount binfmt_misc -t binfmt_misc /proc/sys/fs/binfmt_misc
196 You may say M here for module support and later load the module when
197 you have use for it; the module is called binfmt_misc. If you
198 don't know what to answer at this point, say Y.
201 bool "Enable core dump support" if EXPERT
204 This option enables support for performing core dumps. You almost
205 certainly want to say Y here. Not necessary on systems that never
206 need debugging or only ever run flawless code.