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
41 config TRACE_IRQFLAGS_SUPPORT
45 config LOCKDEP_SUPPORT
49 config STACKTRACE_SUPPORT
54 config GENERIC_CALIBRATE_DELAY
67 source "arch/$(HEADER_ARCH)/um/Kconfig"
70 bool "Force a static link"
73 This option gives you the ability to force a static link of UML.
74 Normally, UML is linked as a shared binary. This is inconvenient for
75 use in a chroot jail. So, if you intend to run UML inside a chroot,
76 you probably want to say Y here.
77 Additionally, this option enables using higher memory spaces (up to
80 config LD_SCRIPT_STATIC
83 depends on STATIC_LINK
88 depends on !LD_SCRIPT_STATIC
89 select MODULE_REL_CRCS if MODVERSIONS
92 tristate "Host filesystem"
94 While the User-Mode Linux port uses its own root file system for
95 booting and normal file access, this module lets the UML user
96 access files stored on the host. It does not require any
97 network connection between the Host and UML. An example use of
100 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
102 where /tmp/fromhost is an empty directory inside UML and
103 /tmp/umlshare is a directory on the host with files the UML user
106 For more information, see
107 <http://user-mode-linux.sourceforge.net/hostfs.html>.
109 If you'd like to be able to work with files stored on the host,
110 say Y or M here; otherwise say N.
113 bool "Management console"
117 The user mode linux management console is a low-level interface to
118 the kernel, somewhat like the i386 SysRq interface. Since there is
119 a full-blown operating system running under every user mode linux
120 instance, there is much greater flexibility possible than with the
123 If you answer 'Y' to this option, to use this feature, you need the
124 mconsole client (called uml_mconsole) which is present in CVS in
125 2.4.5-9um and later (path /tools/mconsole), and is also in the
126 distribution RPM package in 2.4.6 and later.
128 It is safe to say 'Y' here.
131 bool "Magic SysRq key"
134 If you say Y here, you will have some control over the system even
135 if the system crashes for example during kernel debugging (e.g., you
136 will be able to flush the buffer cache to disk, reboot the system
137 immediately or dump some status information). A key for each of the
138 possible requests is provided.
140 This is the feature normally accomplished by pressing a key
141 while holding SysRq (Alt+PrintScreen).
143 On UML, this is accomplished by sending a "sysrq" command with
144 mconsole, followed by the letter for the requested command.
146 The keys are documented in <file:Documentation/admin-guide/sysrq.rst>. Don't say Y
147 unless you really know what this hack does.
149 config KERNEL_STACK_ORDER
150 int "Kernel stack size order"
155 This option determines the size of UML kernel stacks. They will
156 be 1 << order pages. The default is OK unless you're running Valgrind
157 on UML, in which case, set this to 3.
160 tristate "iomem emulation driver"
162 This driver allows a host file to be used as emulated IO memory inside
168 config PGTABLE_LEVELS
170 default 3 if 3_LEVEL_PGTABLES
175 prompt "Enable seccomp to safely compute untrusted bytecode"
177 This kernel feature is useful for number crunching applications
178 that may need to compute untrusted bytecode during their
179 execution. By using pipes or other transports made available to
180 the process as file descriptors supporting the read/write
181 syscalls, it's possible to isolate those applications in
182 their own address space using seccomp. Once seccomp is
183 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
184 and the task is only allowed to execute a few safe syscalls
185 defined by each seccomp mode.
191 source "arch/um/drivers/Kconfig"