xref: /linux/arch/um/Kconfig (revision e0d21d9cca25f424f3129649be48a63c128ed42d)
1# UML uses the generic IRQ sugsystem
2config GENERIC_HARDIRQS
3	bool
4	default y
5
6config UML
7	bool
8	default y
9
10# XXX: does UM have a mmu/swap?
11config MMU
12	bool
13	default y
14
15mainmenu "Linux/Usermode Kernel Configuration"
16
17config ISA
18	bool
19
20config SBUS
21	bool
22
23config PCI
24	bool
25
26config UID16
27	bool
28	default y
29
30config RWSEM_GENERIC_SPINLOCK
31	bool
32	default y
33
34config GENERIC_CALIBRATE_DELAY
35	bool
36	default y
37
38# Used in kernel/irq/manage.c and include/linux/irq.h
39config IRQ_RELEASE_METHOD
40	bool
41	default y
42
43menu "UML-specific options"
44
45config MODE_TT
46	bool "Tracing thread support"
47	default y
48	help
49	This option controls whether tracing thread support is compiled
50	into UML.  Normally, this should be set to Y.  If you intend to
51	use only skas mode (and the host has the skas patch applied to it),
52	then it is OK to say N here.
53
54config STATIC_LINK
55	bool "Force a static link"
56	default n
57	depends on !MODE_TT
58	help
59	If CONFIG_MODE_TT is disabled, then this option gives you the ability
60	to force a static link of UML.  Normally, if only skas mode is built
61	in to UML, it will be linked as a shared binary.  This is inconvenient
62	for use in a chroot jail.  So, if you intend to run UML inside a
63	chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
64	here.
65
66config MODE_SKAS
67	bool "Separate Kernel Address Space support"
68	default y
69	help
70	This option controls whether skas (separate kernel address space)
71	support is compiled in.  If you have applied the skas patch to the
72	host, then you certainly want to say Y here (and consider saying N
73	to CONFIG_MODE_TT).  Otherwise, it is safe to say Y.  Disabling this
74	option will shrink the UML binary slightly.
75
76source "arch/um/Kconfig_arch"
77source "mm/Kconfig"
78
79config LD_SCRIPT_STATIC
80	bool
81	default y
82	depends on MODE_TT || STATIC_LINK
83
84config LD_SCRIPT_DYN
85	bool
86	default y
87	depends on !LD_SCRIPT_STATIC
88
89config NET
90	bool "Networking support"
91	help
92	Unless you really know what you are doing, you should say Y here.
93	The reason is that some programs need kernel networking support even
94	when running on a stand-alone machine that isn't connected to any
95	other computer. If you are upgrading from an older kernel, you
96	should consider updating your networking tools too because changes
97	in the kernel and the tools often go hand in hand. The tools are
98	contained in the package net-tools, the location and version number
99	of which are given in <file:Documentation/Changes>.
100
101	For a general introduction to Linux networking, it is highly
102	recommended to read the NET-HOWTO, available from
103	<http://www.tldp.org/docs.html#howto>.
104
105
106source "fs/Kconfig.binfmt"
107
108config HOSTFS
109	tristate "Host filesystem"
110	help
111        While the User-Mode Linux port uses its own root file system for
112        booting and normal file access, this module lets the UML user
113        access files stored on the host.  It does not require any
114        network connection between the Host and UML.  An example use of
115        this might be:
116
117        mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
118
119        where /tmp/fromhost is an empty directory inside UML and
120        /tmp/umlshare is a directory on the host with files the UML user
121        wishes to access.
122
123        For more information, see
124        <http://user-mode-linux.sourceforge.net/hostfs.html>.
125
126        If you'd like to be able to work with files stored on the host,
127        say Y or M here; otherwise say N.
128
129config HPPFS
130	tristate "HoneyPot ProcFS (EXPERIMENTAL)"
131	help
132	hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
133	entries to be overridden, removed, or fabricated from the host.
134	Its purpose is to allow a UML to appear to be a physical machine
135	by removing or changing anything in /proc which gives away the
136	identity of a UML.
137
138	See <http://user-mode-linux.sf.net/hppfs.html> for more information.
139
140	You only need this if you are setting up a UML honeypot.  Otherwise,
141	it is safe to say 'N' here.
142
143	If you are actively using it, please report any problems, since it's
144	getting fixed. In this moment, it is experimental on 2.6 (it works on
145	2.4).
146
147config MCONSOLE
148	bool "Management console"
149	default y
150	help
151        The user mode linux management console is a low-level interface to
152        the kernel, somewhat like the i386 SysRq interface.  Since there is
153        a full-blown operating system running under every user mode linux
154        instance, there is much greater flexibility possible than with the
155        SysRq mechanism.
156
157        If you answer 'Y' to this option, to use this feature, you need the
158        mconsole client (called uml_mconsole) which is present in CVS in
159        2.4.5-9um and later (path /tools/mconsole), and is also in the
160        distribution RPM package in 2.4.6 and later.
161
162        It is safe to say 'Y' here.
163
164config MAGIC_SYSRQ
165	bool "Magic SysRq key"
166	depends on MCONSOLE
167	---help---
168	If you say Y here, you will have some control over the system even
169	if the system crashes for example during kernel debugging (e.g., you
170	will be able to flush the buffer cache to disk, reboot the system
171	immediately or dump some status information). A key for each of the
172	possible requests is provided.
173
174	This is the feature normally accomplished by pressing a key
175	while holding SysRq (Alt+PrintScreen).
176
177	On UML, this is accomplished by sending a "sysrq" command with
178	mconsole, followed by the letter for the requested command.
179
180	The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
181	unless you really know what this hack does.
182
183config HOST_2G_2G
184	bool "2G/2G host address space split"
185	default n
186	help
187	This is needed when the host on which you run has a 2G/2G memory
188	split, instead of the customary 3G/1G.
189
190	Note that to enable such a host
191	configuration, which makes sense only in some cases, you need special
192	host patches.
193
194	So, if you do not know what to do here, say 'N'.
195
196config SMP
197	bool "Symmetric multi-processing support (EXPERIMENTAL)"
198	default n
199	depends on MODE_TT && EXPERIMENTAL
200	help
201	This option enables UML SMP support.
202	It is NOT related to having a real SMP box. Not directly, at least.
203
204	UML implements virtual SMP by allowing as many processes to run
205	simultaneously on the host as there are virtual processors configured.
206
207	Obviously, if the host is a uniprocessor, those processes will
208	timeshare, but, inside UML, will appear to be running simultaneously.
209	If the host is a multiprocessor, then UML processes may run
210	simultaneously, depending on the host scheduler.
211
212	This, however, is supported only in TT mode. So, if you use the SKAS
213	patch on your host, switching to TT mode and enabling SMP usually gives
214	you worse performances.
215	Also, since the support for SMP has been under-developed, there could
216	be some bugs being exposed by enabling SMP.
217
218	If you don't know what to do, say N.
219
220config NR_CPUS
221	int "Maximum number of CPUs (2-32)"
222	range 2 32
223	depends on SMP
224	default "32"
225
226config NEST_LEVEL
227	int "Nesting level"
228	default "0"
229	help
230        This is set to the number of layers of UMLs that this UML will be run
231        in.  Normally, this is zero, meaning that it will run directly on the
232        host.  Setting it to one will build a UML that can run inside a UML
233        that is running on the host.  Generally, if you intend this UML to run
234        inside another UML, set CONFIG_NEST_LEVEL to one more than the host
235        UML.
236
237        Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
238        greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
239        set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
240        Only change this if you are running nested UMLs.
241
242config KERNEL_HALF_GIGS
243	int "Kernel address space size (in .5G units)"
244	default "1"
245	help
246        This determines the amount of address space that UML will allocate for
247        its own, measured in half Gigabyte units.  The default is 1.
248        Change this only if you need to boot UML with an unusually large amount
249        of physical memory.
250
251config HIGHMEM
252	bool "Highmem support"
253	depends on !64BIT
254
255config KERNEL_STACK_ORDER
256	int "Kernel stack size order"
257	default 2
258	help
259	This option determines the size of UML kernel stacks.  They will
260	be 1 << order pages.  The default is OK unless you're running Valgrind
261	on UML, in which case, set this to 3.
262
263config UML_REAL_TIME_CLOCK
264	bool "Real-time Clock"
265	default y
266	help
267	This option makes UML time deltas match wall clock deltas.  This should
268	normally be enabled.  The exception would be if you are debugging with
269	UML and spend long times with UML stopped at a breakpoint.  In this
270	case, when UML is restarted, it will call the timer enough times to make
271	up for the time spent at the breakpoint.  This could result in a
272	noticable lag.  If this is a problem, then disable this option.
273
274endmenu
275
276source "init/Kconfig"
277
278source "drivers/base/Kconfig"
279
280source "arch/um/Kconfig_char"
281
282source "drivers/block/Kconfig"
283
284config NETDEVICES
285	bool
286	default NET
287
288source "arch/um/Kconfig_net"
289
290source "net/Kconfig"
291
292source "fs/Kconfig"
293
294source "security/Kconfig"
295
296source "crypto/Kconfig"
297
298source "lib/Kconfig"
299
300menu "SCSI support"
301depends on BROKEN
302
303config SCSI
304	tristate "SCSI support"
305
306# This gives us free_dma, which scsi.c wants.
307config GENERIC_ISA_DMA
308	bool
309	depends on SCSI
310	default y
311
312source "arch/um/Kconfig_scsi"
313
314endmenu
315
316source "drivers/md/Kconfig"
317
318if BROKEN
319	source "drivers/mtd/Kconfig"
320endif
321
322#This is just to shut up some Kconfig warnings, so no prompt.
323config INPUT
324	bool
325	default n
326
327source "arch/um/Kconfig.debug"
328