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 GENERIC_CALIBRATE_DELAY
34 # Used in kernel/irq/manage.c and include/linux/irq.h
35 config IRQ_RELEASE_METHOD
39 menu "Host processor type and features"
41 source "arch/i386/Kconfig.cpu"
45 menu "UML-specific options"
48 bool "Tracing thread support"
51 This option controls whether tracing thread support is compiled
52 into UML. Normally, this should be set to Y. If you intend to
53 use only skas mode (and the host has the skas patch applied to it),
54 then it is OK to say N here.
57 bool "Force a static link"
61 If CONFIG_MODE_TT is disabled, then this option gives you the ability
62 to force a static link of UML. Normally, if only skas mode is built
63 in to UML, it will be linked as a shared binary. This is inconvenient
64 for use in a chroot jail. So, if you intend to run UML inside a
65 chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
69 bool "2G/2G host address space split"
73 This is needed when the host on which you run has a 2G/2G memory
74 split, instead of the customary 3G/1G.
76 Note that to enable such a host
77 configuration, which makes sense only in some cases, you need special
80 So, if you do not know what to do here, say 'N'.
82 config KERNEL_HALF_GIGS
83 int "Kernel address space size (in .5G units)"
87 This determines the amount of address space that UML will allocate for
88 its own, measured in half Gigabyte units. The default is 1.
89 Change this only if you need to boot UML with an unusually large amount
93 bool "Separate Kernel Address Space support"
96 This option controls whether skas (separate kernel address space)
97 support is compiled in. If you have applied the skas patch to the
98 host, then you certainly want to say Y here (and consider saying N
99 to CONFIG_MODE_TT). Otherwise, it is safe to say Y. Disabling this
100 option will shrink the UML binary slightly.
102 source "arch/um/Kconfig.arch"
105 config LD_SCRIPT_STATIC
108 depends on MODE_TT || STATIC_LINK
113 depends on !LD_SCRIPT_STATIC
116 bool "Networking support"
118 Unless you really know what you are doing, you should say Y here.
119 The reason is that some programs need kernel networking support even
120 when running on a stand-alone machine that isn't connected to any
121 other computer. If you are upgrading from an older kernel, you
122 should consider updating your networking tools too because changes
123 in the kernel and the tools often go hand in hand. The tools are
124 contained in the package net-tools, the location and version number
125 of which are given in <file:Documentation/Changes>.
127 For a general introduction to Linux networking, it is highly
128 recommended to read the NET-HOWTO, available from
129 <http://www.tldp.org/docs.html#howto>.
132 source "fs/Kconfig.binfmt"
135 tristate "Host filesystem"
137 While the User-Mode Linux port uses its own root file system for
138 booting and normal file access, this module lets the UML user
139 access files stored on the host. It does not require any
140 network connection between the Host and UML. An example use of
143 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
145 where /tmp/fromhost is an empty directory inside UML and
146 /tmp/umlshare is a directory on the host with files the UML user
149 For more information, see
150 <http://user-mode-linux.sourceforge.net/hostfs.html>.
152 If you'd like to be able to work with files stored on the host,
153 say Y or M here; otherwise say N.
156 tristate "HoneyPot ProcFS (EXPERIMENTAL)"
158 hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
159 entries to be overridden, removed, or fabricated from the host.
160 Its purpose is to allow a UML to appear to be a physical machine
161 by removing or changing anything in /proc which gives away the
164 See <http://user-mode-linux.sf.net/hppfs.html> for more information.
166 You only need this if you are setting up a UML honeypot. Otherwise,
167 it is safe to say 'N' here.
169 If you are actively using it, please report any problems, since it's
170 getting fixed. In this moment, it is experimental on 2.6 (it works on
174 bool "Management console"
177 The user mode linux management console is a low-level interface to
178 the kernel, somewhat like the i386 SysRq interface. Since there is
179 a full-blown operating system running under every user mode linux
180 instance, there is much greater flexibility possible than with the
183 If you answer 'Y' to this option, to use this feature, you need the
184 mconsole client (called uml_mconsole) which is present in CVS in
185 2.4.5-9um and later (path /tools/mconsole), and is also in the
186 distribution RPM package in 2.4.6 and later.
188 It is safe to say 'Y' here.
191 bool "Magic SysRq key"
194 If you say Y here, you will have some control over the system even
195 if the system crashes for example during kernel debugging (e.g., you
196 will be able to flush the buffer cache to disk, reboot the system
197 immediately or dump some status information). A key for each of the
198 possible requests is provided.
200 This is the feature normally accomplished by pressing a key
201 while holding SysRq (Alt+PrintScreen).
203 On UML, this is accomplished by sending a "sysrq" command with
204 mconsole, followed by the letter for the requested command.
206 The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
207 unless you really know what this hack does.
210 bool "Symmetric multi-processing support (EXPERIMENTAL)"
212 depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
214 This option enables UML SMP support.
215 It is NOT related to having a real SMP box. Not directly, at least.
217 UML implements virtual SMP by allowing as many processes to run
218 simultaneously on the host as there are virtual processors configured.
220 Obviously, if the host is a uniprocessor, those processes will
221 timeshare, but, inside UML, will appear to be running simultaneously.
222 If the host is a multiprocessor, then UML processes may run
223 simultaneously, depending on the host scheduler.
225 This, however, is supported only in TT mode. So, if you use the SKAS
226 patch on your host, switching to TT mode and enabling SMP usually gives
227 you worse performances.
228 Also, since the support for SMP has been under-developed, there could
229 be some bugs being exposed by enabling SMP.
231 If you don't know what to do, say N.
234 int "Maximum number of CPUs (2-32)"
243 This is set to the number of layers of UMLs that this UML will be run
244 in. Normally, this is zero, meaning that it will run directly on the
245 host. Setting it to one will build a UML that can run inside a UML
246 that is running on the host. Generally, if you intend this UML to run
247 inside another UML, set CONFIG_NEST_LEVEL to one more than the host
250 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
251 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
252 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
253 Only change this if you are running nested UMLs.
256 bool "Highmem support"
259 config KERNEL_STACK_ORDER
260 int "Kernel stack size order"
263 This option determines the size of UML kernel stacks. They will
264 be 1 << order pages. The default is OK unless you're running Valgrind
265 on UML, in which case, set this to 3.
267 config UML_REAL_TIME_CLOCK
268 bool "Real-time Clock"
271 This option makes UML time deltas match wall clock deltas. This should
272 normally be enabled. The exception would be if you are debugging with
273 UML and spend long times with UML stopped at a breakpoint. In this
274 case, when UML is restarted, it will call the timer enough times to make
275 up for the time spent at the breakpoint. This could result in a
276 noticable lag. If this is a problem, then disable this option.
280 source "init/Kconfig"
284 source "drivers/base/Kconfig"
286 source "arch/um/Kconfig.char"
288 source "drivers/block/Kconfig"
294 source "arch/um/Kconfig.net"
296 source "drivers/net/Kconfig"
300 source "security/Kconfig"
302 source "crypto/Kconfig"
310 tristate "SCSI support"
312 # This gives us free_dma, which scsi.c wants.
313 config GENERIC_ISA_DMA
318 source "arch/um/Kconfig.scsi"
322 source "drivers/md/Kconfig"
325 source "drivers/mtd/Kconfig"
328 #This is just to shut up some Kconfig warnings, so no prompt.
333 source "arch/um/Kconfig.debug"