1 # SPDX-License-Identifier: GPL-2.0
3 menu "UML-specific options"
8 select ARCH_HAS_CPU_FINALIZE_INIT
10 select ARCH_NO_PREEMPT
11 select HAVE_ARCH_AUDITSYSCALL
12 select HAVE_ARCH_SECCOMP_FILTER
13 select HAVE_ASM_MODVERSIONS
15 select HAVE_FUTEX_CMPXCHG if FUTEX
16 select HAVE_DEBUG_KMEMLEAK
17 select HAVE_DEBUG_BUGVERBOSE
19 select GENERIC_IRQ_SHOW
20 select GENERIC_CPU_DEVICES
21 select GENERIC_CLOCKEVENTS
22 select HAVE_GCC_PLUGINS
24 select TTY # Needed for line.c
39 config TRACE_IRQFLAGS_SUPPORT
43 config LOCKDEP_SUPPORT
47 config STACKTRACE_SUPPORT
52 config GENERIC_CALIBRATE_DELAY
65 source "arch/$(HEADER_ARCH)/um/Kconfig"
67 config MAY_HAVE_RUNTIME_DEPS
71 bool "Force a static link"
72 depends on CC_CAN_LINK_STATIC_NO_RUNTIME_DEPS || !MAY_HAVE_RUNTIME_DEPS
74 This option gives you the ability to force a static link of UML.
75 Normally, UML is linked as a shared binary. This is inconvenient for
76 use in a chroot jail. So, if you intend to run UML inside a chroot,
77 you probably want to say Y here.
78 Additionally, this option enables using higher memory spaces (up to
81 NOTE: This option is incompatible with some networking features which
82 depend on features that require being dynamically loaded (like NSS).
84 config LD_SCRIPT_STATIC
87 depends on STATIC_LINK
92 depends on !LD_SCRIPT_STATIC
93 select MODULE_REL_CRCS if MODVERSIONS
95 config LD_SCRIPT_DYN_RPATH
96 bool "set rpath in the binary" if EXPERT
98 depends on LD_SCRIPT_DYN
100 Add /lib (and /lib64 for 64-bit) to the linux binary's rpath
103 You may need to turn this off if compiling for nix systems
104 that have their libraries in random /nix directories and
105 might otherwise unexpected use libraries from /lib or /lib64
106 instead of the desired ones.
109 tristate "Host filesystem"
111 While the User-Mode Linux port uses its own root file system for
112 booting and normal file access, this module lets the UML user
113 access files stored on the host. It does not require any
114 network connection between the Host and UML. An example use of
117 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
119 where /tmp/fromhost is an empty directory inside UML and
120 /tmp/umlshare is a directory on the host with files the UML user
123 For more information, see
124 <http://user-mode-linux.sourceforge.net/hostfs.html>.
126 If you'd like to be able to work with files stored on the host,
127 say Y or M here; otherwise say N.
130 bool "Management console"
134 The user mode linux management console is a low-level interface to
135 the kernel, somewhat like the i386 SysRq interface. Since there is
136 a full-blown operating system running under every user mode linux
137 instance, there is much greater flexibility possible than with the
140 If you answer 'Y' to this option, to use this feature, you need the
141 mconsole client (called uml_mconsole) which is present in CVS in
142 2.4.5-9um and later (path /tools/mconsole), and is also in the
143 distribution RPM package in 2.4.6 and later.
145 It is safe to say 'Y' here.
148 bool "Magic SysRq key"
151 If you say Y here, you will have some control over the system even
152 if the system crashes for example during kernel debugging (e.g., you
153 will be able to flush the buffer cache to disk, reboot the system
154 immediately or dump some status information). A key for each of the
155 possible requests is provided.
157 This is the feature normally accomplished by pressing a key
158 while holding SysRq (Alt+PrintScreen).
160 On UML, this is accomplished by sending a "sysrq" command with
161 mconsole, followed by the letter for the requested command.
163 The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
164 unless you really know what this hack does.
166 config KERNEL_STACK_ORDER
167 int "Kernel stack size order"
172 This option determines the size of UML kernel stacks. They will
173 be 1 << order pages. The default is OK unless you're running Valgrind
174 on UML, in which case, set this to 3.
175 It is possible to reduce the stack to 1 for 64BIT and 0 for 32BIT on
176 older (pre-2017) CPUs. It is not recommended on newer CPUs due to the
177 increase in the size of the state which needs to be saved when handling
181 tristate "iomem emulation driver"
183 This driver allows a host file to be used as emulated IO memory inside
186 config PGTABLE_LEVELS
188 default 3 if 3_LEVEL_PGTABLES
191 config UML_TIME_TRAVEL_SUPPORT
193 prompt "Support time-travel mode (e.g. for test execution)"
194 # inf-cpu mode is incompatible with the benchmarking
195 depends on !RAID6_PQ_BENCHMARK
198 Enable this option to support time travel inside the UML instance.
200 After enabling this option, two modes are accessible at runtime
201 (selected by the kernel command line), see the kernel's command-
202 line help for more details.
204 It is safe to say Y, but you probably don't need this.
208 source "arch/um/drivers/Kconfig"
210 config ARCH_SUSPEND_POSSIBLE
213 source "kernel/power/Kconfig"