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