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 "Host filesystem"
89 While the User-Mode Linux port uses its own root file system for
90 booting and normal file access, this module lets the UML user
91 access files stored on the host. It does not require any
92 network connection between the Host and UML. An example use of
95 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
97 where /tmp/fromhost is an empty directory inside UML and
98 /tmp/umlshare is a directory on the host with files the UML user
101 For more information, see
102 <http://user-mode-linux.sourceforge.net/hostfs.html>.
104 If you'd like to be able to work with files stored on the host,
105 say Y or M here; otherwise say N.
108 tristate "HoneyPot ProcFS (EXPERIMENTAL)"
111 hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
112 entries to be overridden, removed, or fabricated from the host.
113 Its purpose is to allow a UML to appear to be a physical machine
114 by removing or changing anything in /proc which gives away the
117 See http://user-mode-linux.sf.net/hppfs.html for more information.
119 You only need this if you are setting up a UML honeypot. Otherwise,
120 it is safe to say 'N' here.
122 If you are actively using it, please ask for it to be fixed. In this
123 moment, it does not work on 2.6 (it works somehow on 2.4).
126 bool "Management console"
129 The user mode linux management console is a low-level interface to
130 the kernel, somewhat like the i386 SysRq interface. Since there is
131 a full-blown operating system running under every user mode linux
132 instance, there is much greater flexibility possible than with the
135 If you answer 'Y' to this option, to use this feature, you need the
136 mconsole client (called uml_mconsole) which is present in CVS in
137 2.4.5-9um and later (path /tools/mconsole), and is also in the
138 distribution RPM package in 2.4.6 and later.
140 It is safe to say 'Y' here.
143 bool "2G/2G host address space split"
146 This is needed when the host on which you run has a 2G/2G memory
147 split, instead of the customary 3G/1G.
149 Note that to enable such a host
150 configuration, which makes sense only in some cases, you need special
153 So, if you do not know what to do here, say 'N'.
156 bool "Symmetric multi-processing support (EXPERIMENTAL)"
158 depends on MODE_TT && EXPERIMENTAL
160 This option enables UML SMP support.
161 It is NOT related to having a real SMP box. Not directly, at least.
163 UML implements virtual SMP by allowing as many processes to run
164 simultaneously on the host as there are virtual processors configured.
166 Obviously, if the host is a uniprocessor, those processes will
167 timeshare, but, inside UML, will appear to be running simultaneously.
168 If the host is a multiprocessor, then UML processes may run
169 simultaneously, depending on the host scheduler.
171 This, however, is supported only in TT mode. So, if you use the SKAS
172 patch on your host, switching to TT mode and enabling SMP usually gives
173 you worse performances.
174 Also, since the support for SMP has been under-developed, there could
175 be some bugs being exposed by enabling SMP.
177 If you don't know what to do, say N.
180 int "Maximum number of CPUs (2-32)"
189 This is set to the number of layers of UMLs that this UML will be run
190 in. Normally, this is zero, meaning that it will run directly on the
191 host. Setting it to one will build a UML that can run inside a UML
192 that is running on the host. Generally, if you intend this UML to run
193 inside another UML, set CONFIG_NEST_LEVEL to one more than the host
196 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
197 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
198 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
199 Only change this if you are running nested UMLs.
201 config KERNEL_HALF_GIGS
202 int "Kernel address space size (in .5G units)"
205 This determines the amount of address space that UML will allocate for
206 its own, measured in half Gigabyte units. The default is 1.
207 Change this only if you need to boot UML with an unusually large amount
211 bool "Highmem support"
214 config KERNEL_STACK_ORDER
215 int "Kernel stack size order"
218 This option determines the size of UML kernel stacks. They will
219 be 1 << order pages. The default is OK unless you're running Valgrind
220 on UML, in which case, set this to 3.
222 config UML_REAL_TIME_CLOCK
223 bool "Real-time Clock"
226 This option makes UML time deltas match wall clock deltas. This should
227 normally be enabled. The exception would be if you are debugging with
228 UML and spend long times with UML stopped at a breakpoint. In this
229 case, when UML is restarted, it will call the timer enough times to make
230 up for the time spent at the breakpoint. This could result in a
231 noticable lag. If this is a problem, then disable this option.
235 source "init/Kconfig"
237 source "drivers/base/Kconfig"
239 source "arch/um/Kconfig_char"
241 source "arch/um/Kconfig_block"
247 source "arch/um/Kconfig_net"
253 source "kernel/vserver/Kconfig"
255 source "security/Kconfig"
257 source "crypto/Kconfig"
265 tristate "SCSI support"
267 # This gives us free_dma, which scsi.c wants.
268 config GENERIC_ISA_DMA
273 source "arch/um/Kconfig_scsi"
277 source "drivers/md/Kconfig"
280 source "drivers/mtd/Kconfig"
287 source "arch/um/Kconfig.debug"