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 "Separate Kernel Address Space support"
72 This option controls whether skas (separate kernel address space)
73 support is compiled in. If you have applied the skas patch to the
74 host, then you certainly want to say Y here (and consider saying N
75 to CONFIG_MODE_TT). Otherwise, it is safe to say Y. Disabling this
76 option will shrink the UML binary slightly.
78 source "arch/um/Kconfig.arch"
81 config LD_SCRIPT_STATIC
84 depends on MODE_TT || STATIC_LINK
89 depends on !LD_SCRIPT_STATIC
92 bool "Networking support"
94 Unless you really know what you are doing, you should say Y here.
95 The reason is that some programs need kernel networking support even
96 when running on a stand-alone machine that isn't connected to any
97 other computer. If you are upgrading from an older kernel, you
98 should consider updating your networking tools too because changes
99 in the kernel and the tools often go hand in hand. The tools are
100 contained in the package net-tools, the location and version number
101 of which are given in <file:Documentation/Changes>.
103 For a general introduction to Linux networking, it is highly
104 recommended to read the NET-HOWTO, available from
105 <http://www.tldp.org/docs.html#howto>.
108 source "fs/Kconfig.binfmt"
111 tristate "Host filesystem"
113 While the User-Mode Linux port uses its own root file system for
114 booting and normal file access, this module lets the UML user
115 access files stored on the host. It does not require any
116 network connection between the Host and UML. An example use of
119 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
121 where /tmp/fromhost is an empty directory inside UML and
122 /tmp/umlshare is a directory on the host with files the UML user
125 For more information, see
126 <http://user-mode-linux.sourceforge.net/hostfs.html>.
128 If you'd like to be able to work with files stored on the host,
129 say Y or M here; otherwise say N.
132 tristate "HoneyPot ProcFS (EXPERIMENTAL)"
134 hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
135 entries to be overridden, removed, or fabricated from the host.
136 Its purpose is to allow a UML to appear to be a physical machine
137 by removing or changing anything in /proc which gives away the
140 See <http://user-mode-linux.sf.net/hppfs.html> for more information.
142 You only need this if you are setting up a UML honeypot. Otherwise,
143 it is safe to say 'N' here.
145 If you are actively using it, please report any problems, since it's
146 getting fixed. In this moment, it is experimental on 2.6 (it works on
150 bool "Management console"
153 The user mode linux management console is a low-level interface to
154 the kernel, somewhat like the i386 SysRq interface. Since there is
155 a full-blown operating system running under every user mode linux
156 instance, there is much greater flexibility possible than with the
159 If you answer 'Y' to this option, to use this feature, you need the
160 mconsole client (called uml_mconsole) which is present in CVS in
161 2.4.5-9um and later (path /tools/mconsole), and is also in the
162 distribution RPM package in 2.4.6 and later.
164 It is safe to say 'Y' here.
167 bool "Magic SysRq key"
170 If you say Y here, you will have some control over the system even
171 if the system crashes for example during kernel debugging (e.g., you
172 will be able to flush the buffer cache to disk, reboot the system
173 immediately or dump some status information). A key for each of the
174 possible requests is provided.
176 This is the feature normally accomplished by pressing a key
177 while holding SysRq (Alt+PrintScreen).
179 On UML, this is accomplished by sending a "sysrq" command with
180 mconsole, followed by the letter for the requested command.
182 The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
183 unless you really know what this hack does.
186 bool "2G/2G host address space split"
189 This is needed when the host on which you run has a 2G/2G memory
190 split, instead of the customary 3G/1G.
192 Note that to enable such a host
193 configuration, which makes sense only in some cases, you need special
196 So, if you do not know what to do here, say 'N'.
199 bool "Symmetric multi-processing support (EXPERIMENTAL)"
201 depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
203 This option enables UML SMP support.
204 It is NOT related to having a real SMP box. Not directly, at least.
206 UML implements virtual SMP by allowing as many processes to run
207 simultaneously on the host as there are virtual processors configured.
209 Obviously, if the host is a uniprocessor, those processes will
210 timeshare, but, inside UML, will appear to be running simultaneously.
211 If the host is a multiprocessor, then UML processes may run
212 simultaneously, depending on the host scheduler.
214 This, however, is supported only in TT mode. So, if you use the SKAS
215 patch on your host, switching to TT mode and enabling SMP usually gives
216 you worse performances.
217 Also, since the support for SMP has been under-developed, there could
218 be some bugs being exposed by enabling SMP.
220 If you don't know what to do, say N.
223 int "Maximum number of CPUs (2-32)"
232 This is set to the number of layers of UMLs that this UML will be run
233 in. Normally, this is zero, meaning that it will run directly on the
234 host. Setting it to one will build a UML that can run inside a UML
235 that is running on the host. Generally, if you intend this UML to run
236 inside another UML, set CONFIG_NEST_LEVEL to one more than the host
239 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
240 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
241 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
242 Only change this if you are running nested UMLs.
244 config KERNEL_HALF_GIGS
245 int "Kernel address space size (in .5G units)"
248 This determines the amount of address space that UML will allocate for
249 its own, measured in half Gigabyte units. The default is 1.
250 Change this only if you need to boot UML with an unusually large amount
254 bool "Highmem support"
257 config KERNEL_STACK_ORDER
258 int "Kernel stack size order"
261 This option determines the size of UML kernel stacks. They will
262 be 1 << order pages. The default is OK unless you're running Valgrind
263 on UML, in which case, set this to 3.
265 config UML_REAL_TIME_CLOCK
266 bool "Real-time Clock"
269 This option makes UML time deltas match wall clock deltas. This should
270 normally be enabled. The exception would be if you are debugging with
271 UML and spend long times with UML stopped at a breakpoint. In this
272 case, when UML is restarted, it will call the timer enough times to make
273 up for the time spent at the breakpoint. This could result in a
274 noticable lag. If this is a problem, then disable this option.
278 source "init/Kconfig"
282 source "drivers/base/Kconfig"
284 source "arch/um/Kconfig.char"
286 source "drivers/block/Kconfig"
292 source "arch/um/Kconfig.net"
294 source "drivers/net/Kconfig"
298 source "security/Kconfig"
300 source "crypto/Kconfig"
308 tristate "SCSI support"
310 # This gives us free_dma, which scsi.c wants.
311 config GENERIC_ISA_DMA
316 source "arch/um/Kconfig.scsi"
320 source "drivers/md/Kconfig"
323 source "drivers/mtd/Kconfig"
326 #This is just to shut up some Kconfig warnings, so no prompt.
331 source "arch/um/Kconfig.debug"