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
17 select GENERIC_IRQ_SHOW
18 select GENERIC_CPU_DEVICES
19 select GENERIC_CLOCKEVENTS
20 select HAVE_GCC_PLUGINS
21 select TTY # Needed for line.c
42 config TRACE_IRQFLAGS_SUPPORT
46 config LOCKDEP_SUPPORT
50 config STACKTRACE_SUPPORT
55 config GENERIC_CALIBRATE_DELAY
68 source "arch/$(HEADER_ARCH)/um/Kconfig"
71 bool "Force a static link"
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 config LD_SCRIPT_STATIC
84 depends on STATIC_LINK
89 depends on !LD_SCRIPT_STATIC
90 select MODULE_REL_CRCS if MODVERSIONS
93 tristate "Host filesystem"
95 While the User-Mode Linux port uses its own root file system for
96 booting and normal file access, this module lets the UML user
97 access files stored on the host. It does not require any
98 network connection between the Host and UML. An example use of
101 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
103 where /tmp/fromhost is an empty directory inside UML and
104 /tmp/umlshare is a directory on the host with files the UML user
107 For more information, see
108 <http://user-mode-linux.sourceforge.net/hostfs.html>.
110 If you'd like to be able to work with files stored on the host,
111 say Y or M here; otherwise say N.
114 bool "Management console"
118 The user mode linux management console is a low-level interface to
119 the kernel, somewhat like the i386 SysRq interface. Since there is
120 a full-blown operating system running under every user mode linux
121 instance, there is much greater flexibility possible than with the
124 If you answer 'Y' to this option, to use this feature, you need the
125 mconsole client (called uml_mconsole) which is present in CVS in
126 2.4.5-9um and later (path /tools/mconsole), and is also in the
127 distribution RPM package in 2.4.6 and later.
129 It is safe to say 'Y' here.
132 bool "Magic SysRq key"
135 If you say Y here, you will have some control over the system even
136 if the system crashes for example during kernel debugging (e.g., you
137 will be able to flush the buffer cache to disk, reboot the system
138 immediately or dump some status information). A key for each of the
139 possible requests is provided.
141 This is the feature normally accomplished by pressing a key
142 while holding SysRq (Alt+PrintScreen).
144 On UML, this is accomplished by sending a "sysrq" command with
145 mconsole, followed by the letter for the requested command.
147 The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
148 unless you really know what this hack does.
150 config KERNEL_STACK_ORDER
151 int "Kernel stack size order"
156 This option determines the size of UML kernel stacks. They will
157 be 1 << order pages. The default is OK unless you're running Valgrind
158 on UML, in which case, set this to 3.
161 tristate "iomem emulation driver"
163 This driver allows a host file to be used as emulated IO memory inside
169 config PGTABLE_LEVELS
171 default 3 if 3_LEVEL_PGTABLES
176 prompt "Enable seccomp to safely compute untrusted bytecode"
178 This kernel feature is useful for number crunching applications
179 that may need to compute untrusted bytecode during their
180 execution. By using pipes or other transports made available to
181 the process as file descriptors supporting the read/write
182 syscalls, it's possible to isolate those applications in
183 their own address space using seccomp. Once seccomp is
184 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
185 and the task is only allowed to execute a few safe syscalls
186 defined by each seccomp mode.
192 source "arch/um/drivers/Kconfig"