5 # XXX: does UM have a mmu/swap?
10 mainmenu "Linux/Usermode Kernel Configuration"
25 config RWSEM_GENERIC_SPINLOCK
29 menu "UML-specific options"
32 bool "Tracing thread support"
35 This option controls whether tracing thread support is compiled
36 into UML. Normally, this should be set to Y. If you intend to
37 use only skas mode (and the host has the skas patch applied to it),
38 then it is OK to say N here.
41 bool "Force a static link"
45 If CONFIG_MODE_TT is disabled, then this option gives you the ability
46 to force a static link of UML. Normally, if only skas mode is built
47 in to UML, it will be linked as a shared binary. This is inconvenient
48 for use in a chroot jail. So, if you intend to run UML inside a
49 chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
53 bool "Separate Kernel Address Space support"
56 This option controls whether skas (separate kernel address space)
57 support is compiled in. If you have applied the skas patch to the
58 host, then you certainly want to say Y here (and consider saying N
59 to CONFIG_MODE_TT). Otherwise, it is safe to say Y. Disabling this
60 option will shrink the UML binary slightly.
63 bool "Networking support"
65 source "fs/Kconfig.binfmt"
68 tristate "Host filesystem"
70 While the User-Mode Linux port uses its own root file system for
71 booting and normal file access, this module lets the UML user
72 access files stored on the host. It does not require any
73 network connection between the Host and UML. An example use of
76 mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
78 where /tmp/fromhost is an empty directory inside UML and
79 /tmp/umlshare is a directory on the host with files the UML user
82 For more information, see
83 <http://user-mode-linux.sourceforge.net/hostfs.html>.
85 If you'd like to be able to work with files stored on the host,
86 say Y or M here; otherwise say N.
90 bool "Management console"
92 The user mode linux management console is a low-level interface to
93 the kernel, somewhat like the i386 SysRq interface. Since there is
94 a full-blown operating system running under every user mode linux
95 instance, there is much greater flexibility possible than with the
98 If you answer 'Y' to this option, to use this feature, you need the
99 mconsole client (called uml_mconsole) which is present in CVS in
100 2.4.5-9um and later (path /tools/mconsole), and is also in the
101 distribution RPM package in 2.4.6 and later.
103 It is safe to say 'Y' here.
106 bool "Magic SysRq key"
110 bool "2G/2G host address space split"
113 bool "Symmetric multi-processing support"
115 This option enables UML SMP support. UML implements virtual SMP by
116 allowing as many processes to run simultaneously on the host as
117 there are virtual processors configured. Obviously, if the host is
118 a uniprocessor, those processes will timeshare, but, inside UML,
119 will appear to be running simultaneously. If the host is a
120 multiprocessor, then UML processes may run simultaneously, depending
121 on the host scheduler.
122 CONFIG_SMP will be set to whatever this option is set to.
123 It is safe to leave this unchanged.
130 int "Maximum number of CPUs (2-32)"
139 This is set to the number of layers of UMLs that this UML will be run
140 in. Normally, this is zero, meaning that it will run directly on the
141 host. Setting it to one will build a UML that can run inside a UML
142 that is running on the host. Generally, if you intend this UML to run
143 inside another UML, set CONFIG_NEST_LEVEL to one more than the host
146 Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
147 greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
148 set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
149 Only change this if you are running nested UMLs.
151 config KERNEL_HALF_GIGS
152 int "Kernel address space size (in .5G units)"
155 This determines the amount of address space that UML will allocate for
156 its own, measured in half Gigabyte units. The default is 1.
157 Change this only if you need to boot UML with an unusually large amount
161 bool "Highmem support"
163 config KERNEL_STACK_ORDER
164 int "Kernel stack size order"
167 This option determines the size of UML kernel stacks. They will
168 be 1 << order pages. The default is OK unless you're running Valgrind
169 on UML, in which case, set this to 3.
173 source "init/Kconfig"
175 source "drivers/base/Kconfig"
177 source "arch/um/Kconfig_char"
179 source "arch/um/Kconfig_block"
185 source "arch/um/Kconfig_net"
191 source "kernel/vserver/Kconfig"
193 source "security/Kconfig"
195 source "crypto/Kconfig"
202 tristate "SCSI support"
204 # This gives us free_dma, which scsi.c wants.
205 config GENERIC_ISA_DMA
210 source "arch/um/Kconfig_scsi"
214 source "drivers/md/Kconfig"
216 source "drivers/mtd/Kconfig"
219 menu "Kernel hacking"
222 bool "Debug memory allocations"
224 config DEBUG_SPINLOCK
225 bool "Debug spinlocks usage"
228 bool "Enable kernel debugging symbols"
230 When this is enabled, the User-Mode Linux binary will include
231 debugging symbols. This enlarges the binary by a few megabytes,
232 but aids in tracking down kernel problems in UML. It is required
233 if you intend to do any kernel development.
235 If you're truly short on disk space or don't expect to report any
236 bugs back to the UML developers, say N, otherwise say Y.
240 default y if DEBUG_INFO
243 bool "Enable ptrace proxy"
244 depends on XTERM_CHAN && DEBUG_INFO
247 bool "Enable gprof support"
248 depends on DEBUG_INFO
250 This allows profiling of a User-Mode Linux kernel with the gprof
253 See <http://user-mode-linux.sourceforge.net/gprof.html> for more
256 If you're involved in UML kernel development and want to use gprof,
257 say Y. If you're unsure, say N.
260 bool "Enable gcov support"
261 depends on DEBUG_INFO
263 This option allows developers to retrieve coverage data from a UML
266 See <http://user-mode-linux.sourceforge.net/gprof.html> for more
269 If you're involved in UML kernel development and want to use gcov,
270 say Y. If you're unsure, say N.