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34 To compile support for this ABI into an i386 kernel
35 place the following line in your
36 kernel configuration file:
37 .Bd -ragged -offset indent
38 .Cd "options COMPAT_LINUX"
41 for an amd64 kernel use:
42 .Bd -ragged -offset indent
43 .Cd "options COMPAT_LINUX32"
46 Alternatively, to load the ABI as a
47 module at boot time, place the following line in
49 .Bd -literal -offset indent
55 module provides limited Linux ABI (application binary interface) compatibility,
56 making it possible to run many unmodified Linux applications and libraries
57 without the need for virtualization or emulation.
58 Some of the facilities provided are:
66 Special signal handling for activated images
68 Linux to native system call translation
70 Linux-specific system calls
73 Note that dynamically linked Linux executables
74 will require a suitable environment in
76 This includes native Linux shared libraries, and Linux-specific virtual
78 To set it up, install the
79 .Pa emulators/linux_base-c7
80 port or the linux_base-c7
81 package, and add the following line to the
85 .Dl linux_enable="YES"
87 To avoid mounting Linux-specific filesystems at startup, also add the following
90 .Dl linux_mounts_enable="NO"
92 The following variables are available as both
97 .Bl -tag -width indent
98 .It Va compat.linux.debug
99 Enable debugging messages.
100 Set to 0 to silence them.
102 .It Va compat.linux.default_openfiles
103 Default soft openfiles resource limit for Linux applications.
104 Set to -1 to disable the limit.
106 .It Va compat.linux.emul_path
107 Path to the Linux run-time environment.
110 .It Va compat.linux.osname
111 Linux kernel operating system name.
112 .It Va compat.linux.osrelease
113 Linux kernel operating system release.
114 Changing this to something else is discouraged on non-development systems,
115 because it may change the way Linux programs work.
116 Recent versions of GNU libc are known to use different syscalls depending
117 on the value of this sysctl.
118 .It Va compat.linux.oss_version
119 Linux Open Sound System version.
120 .It Va compat.linux.preserve_vstatus
121 When set to 1, it prevents Linux applications from resetting the
124 From a user perspective, this makes
126 work for Linux executables.
130 .Bl -tag -width /compat/linux/dev/shm -compact
132 minimal Linux run-time environment
133 .It Pa /compat/linux/dev
134 device file system, see
136 .It Pa /compat/linux/dev/fd
137 file descriptor file system mounted with the
141 .It Pa /compat/linux/dev/shm
142 in-memory file system, see
144 .It Pa /compat/linux/proc
145 Linux process file system, see
147 .It Pa /compat/linux/sys
148 Linux kernel objects file system, see
160 Linux ABI support first appeared in
163 Support for some of the Linux-specific system calls and system call arguments