1 # SPDX-License-Identifier: GPL-2.0
3 menu "UML-specific options"
10 select HAVE_ARCH_AUDITSYSCALL
11 select HAVE_ARCH_SECCOMP_FILTER
13 select HAVE_FUTEX_CMPXCHG if FUTEX
14 select HAVE_DEBUG_KMEMLEAK
15 select HAVE_DEBUG_BUGVERBOSE
16 select GENERIC_IRQ_SHOW
17 select GENERIC_CPU_DEVICES
18 select GENERIC_CLOCKEVENTS
19 select HAVE_GCC_PLUGINS
20 select TTY # Needed for line.c
35 config TRACE_IRQFLAGS_SUPPORT
39 config LOCKDEP_SUPPORT
43 config STACKTRACE_SUPPORT
48 config GENERIC_CALIBRATE_DELAY
61 source "arch/$(HEADER_ARCH)/um/Kconfig"
64 bool "Force a static link"
67 This option gives you the ability to force a static link of UML.
68 Normally, UML is linked as a shared binary. This is inconvenient for
69 use in a chroot jail. So, if you intend to run UML inside a chroot,
70 you probably want to say Y here.
71 Additionally, this option enables using higher memory spaces (up to
74 config LD_SCRIPT_STATIC
77 depends on STATIC_LINK
82 depends on !LD_SCRIPT_STATIC
83 select MODULE_REL_CRCS if MODVERSIONS
86 tristate "Host filesystem"
88 While the User-Mode Linux port uses its own root file system for
89 booting and normal file access, this module lets the UML user
90 access files stored on the host. It does not require any
91 network connection between the Host and UML. An example use of
94 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
96 where /tmp/fromhost is an empty directory inside UML and
97 /tmp/umlshare is a directory on the host with files the UML user
100 For more information, see
101 <http://user-mode-linux.sourceforge.net/hostfs.html>.
103 If you'd like to be able to work with files stored on the host,
104 say Y or M here; otherwise say N.
107 bool "Management console"
111 The user mode linux management console is a low-level interface to
112 the kernel, somewhat like the i386 SysRq interface. Since there is
113 a full-blown operating system running under every user mode linux
114 instance, there is much greater flexibility possible than with the
117 If you answer 'Y' to this option, to use this feature, you need the
118 mconsole client (called uml_mconsole) which is present in CVS in
119 2.4.5-9um and later (path /tools/mconsole), and is also in the
120 distribution RPM package in 2.4.6 and later.
122 It is safe to say 'Y' here.
125 bool "Magic SysRq key"
128 If you say Y here, you will have some control over the system even
129 if the system crashes for example during kernel debugging (e.g., you
130 will be able to flush the buffer cache to disk, reboot the system
131 immediately or dump some status information). A key for each of the
132 possible requests is provided.
134 This is the feature normally accomplished by pressing a key
135 while holding SysRq (Alt+PrintScreen).
137 On UML, this is accomplished by sending a "sysrq" command with
138 mconsole, followed by the letter for the requested command.
140 The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
141 unless you really know what this hack does.
143 config KERNEL_STACK_ORDER
144 int "Kernel stack size order"
149 This option determines the size of UML kernel stacks. They will
150 be 1 << order pages. The default is OK unless you're running Valgrind
151 on UML, in which case, set this to 3.
154 tristate "iomem emulation driver"
156 This driver allows a host file to be used as emulated IO memory inside
162 config PGTABLE_LEVELS
164 default 3 if 3_LEVEL_PGTABLES
169 prompt "Enable seccomp to safely compute untrusted bytecode"
171 This kernel feature is useful for number crunching applications
172 that may need to compute untrusted bytecode during their
173 execution. By using pipes or other transports made available to
174 the process as file descriptors supporting the read/write
175 syscalls, it's possible to isolate those applications in
176 their own address space using seccomp. Once seccomp is
177 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
178 and the task is only allowed to execute a few safe syscalls
179 defined by each seccomp mode.
185 source "arch/um/drivers/Kconfig"