1 # UML uses the generic IRQ sugsystem
2 config GENERIC_HARDIRQS
10 # XXX: does UM have a mmu/swap?
15 mainmenu "Linux/Usermode Kernel Configuration"
30 config RWSEM_GENERIC_SPINLOCK
34 menu "UML-specific options"
37 bool "Tracing thread support"
40 This option controls whether tracing thread support is compiled
41 into UML. Normally, this should be set to Y. If you intend to
42 use only skas mode (and the host has the skas patch applied to it),
43 then it is OK to say N here.
46 bool "Force a static link"
50 If CONFIG_MODE_TT is disabled, then this option gives you the ability
51 to force a static link of UML. Normally, if only skas mode is built
52 in to UML, it will be linked as a shared binary. This is inconvenient
53 for use in a chroot jail. So, if you intend to run UML inside a
54 chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
58 bool "Separate Kernel Address Space support"
61 This option controls whether skas (separate kernel address space)
62 support is compiled in. If you have applied the skas patch to the
63 host, then you certainly want to say Y here (and consider saying N
64 to CONFIG_MODE_TT). Otherwise, it is safe to say Y. Disabling this
65 option will shrink the UML binary slightly.
68 bool "Networking support"
70 Unless you really know what you are doing, you should say Y here.
71 The reason is that some programs need kernel networking support even
72 when running on a stand-alone machine that isn't connected to any
73 other computer. If you are upgrading from an older kernel, you
74 should consider updating your networking tools too because changes
75 in the kernel and the tools often go hand in hand. The tools are
76 contained in the package net-tools, the location and version number
77 of which are given in Documentation/Changes.
79 For a general introduction to Linux networking, it is highly
80 recommended to read the NET-HOWTO, available from
81 <http://www.tldp.org/docs.html#howto>.
84 source "fs/Kconfig.binfmt"
87 tristate "Support for host-based filesystems"
90 tristate "Host filesystem"
92 While the User-Mode Linux port uses its own root file system for
93 booting and normal file access, this module lets the UML user
94 access files stored on the host. It does not require any
95 network connection between the Host and UML. An example use of
98 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
100 where /tmp/fromhost is an empty directory inside UML and
101 /tmp/umlshare is a directory on the host with files the UML user
104 For more information, see
105 <http://user-mode-linux.sourceforge.net/hostfs.html>.
107 If you'd like to be able to work with files stored on the host,
108 say Y or M here; otherwise say N.
111 tristate 'Usable host filesystem'
115 tristate "HoneyPot ProcFS (EXPERIMENTAL)"
118 hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
119 entries to be overridden, removed, or fabricated from the host.
120 Its purpose is to allow a UML to appear to be a physical machine
121 by removing or changing anything in /proc which gives away the
124 See http://user-mode-linux.sf.net/hppfs.html for more information.
126 You only need this if you are setting up a UML honeypot. Otherwise,
127 it is safe to say 'N' here.
129 If you are actively using it, please ask for it to be fixed. In this
130 moment, it does not work on 2.6 (it works somehow on 2.4).
133 bool "Management console"
136 The user mode linux management console is a low-level interface to
137 the kernel, somewhat like the i386 SysRq interface. Since there is
138 a full-blown operating system running under every user mode linux
139 instance, there is much greater flexibility possible than with the
142 If you answer 'Y' to this option, to use this feature, you need the
143 mconsole client (called uml_mconsole) which is present in CVS in
144 2.4.5-9um and later (path /tools/mconsole), and is also in the
145 distribution RPM package in 2.4.6 and later.
147 It is safe to say 'Y' here.
150 bool "2G/2G host address space split"
153 This is needed when the host on which you run has a 2G/2G memory
154 split, instead of the customary 3G/1G.
156 Note that to enable such a host
157 configuration, which makes sense only in some cases, you need special
160 So, if you do not know what to do here, say 'N'.
163 bool "Symmetric multi-processing support (EXPERIMENTAL)"
165 depends on MODE_TT && EXPERIMENTAL
167 This option enables UML SMP support.
168 It is NOT related to having a real SMP box. Not directly, at least.
170 UML implements virtual SMP by allowing as many processes to run
171 simultaneously on the host as there are virtual processors configured.
173 Obviously, if the host is a uniprocessor, those processes will
174 timeshare, but, inside UML, will appear to be running simultaneously.
175 If the host is a multiprocessor, then UML processes may run
176 simultaneously, depending on the host scheduler.
178 This, however, is supported only in TT mode. So, if you use the SKAS
179 patch on your host, switching to TT mode and enabling SMP usually gives
180 you worse performances.
181 Also, since the support for SMP has been under-developed, there could
182 be some bugs being exposed by enabling SMP.
184 If you don't know what to do, say N.
187 int "Maximum number of CPUs (2-32)"
196 This is set to the number of layers of UMLs that this UML will be run
197 in. Normally, this is zero, meaning that it will run directly on the
198 host. Setting it to one will build a UML that can run inside a UML
199 that is running on the host. Generally, if you intend this UML to run
200 inside another UML, set CONFIG_NEST_LEVEL to one more than the host
203 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
204 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
205 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
206 Only change this if you are running nested UMLs.
208 config KERNEL_HALF_GIGS
209 int "Kernel address space size (in .5G units)"
212 This determines the amount of address space that UML will allocate for
213 its own, measured in half Gigabyte units. The default is 1.
214 Change this only if you need to boot UML with an unusually large amount
218 bool "Highmem support"
222 bool "/proc/mm support"
224 config KERNEL_STACK_ORDER
225 int "Kernel stack size order"
228 This option determines the size of UML kernel stacks. They will
229 be 1 << order pages. The default is OK unless you're running Valgrind
230 on UML, in which case, set this to 3.
232 config UML_REAL_TIME_CLOCK
233 bool "Real-time Clock"
236 This option makes UML time deltas match wall clock deltas. This should
237 normally be enabled. The exception would be if you are debugging with
238 UML and spend long times with UML stopped at a breakpoint. In this
239 case, when UML is restarted, it will call the timer enough times to make
240 up for the time spent at the breakpoint. This could result in a
241 noticable lag. If this is a problem, then disable this option.
245 source "init/Kconfig"
247 source "drivers/base/Kconfig"
249 source "arch/um/Kconfig_char"
251 source "arch/um/Kconfig_block"
257 source "arch/um/Kconfig_net"
263 source "kernel/vserver/Kconfig"
265 source "security/Kconfig"
267 source "crypto/Kconfig"
275 tristate "SCSI support"
277 # This gives us free_dma, which scsi.c wants.
278 config GENERIC_ISA_DMA
283 source "arch/um/Kconfig_scsi"
287 source "drivers/md/Kconfig"
290 source "drivers/mtd/Kconfig"
297 source "arch/um/Kconfig.debug"