arch/um/Kconfig

   1 # UML uses the generic IRQ sugsystem
   2 config GENERIC_HARDIRQS
   3         bool
   4         default y
   5
   6 config UML
   7         bool
   8         default y
   9
  10 # XXX: does UM have a mmu/swap?
  11 config MMU
  12         bool
  13         default y
  14
  15 mainmenu "Linux/Usermode Kernel Configuration"
  16
  17 config ISA
  18         bool
  19
  20 config SBUS
  21         bool
  22
  23 config PCI
  24         bool
  25
  26 config UID16
  27         bool
  28         default y
  29
  30 config RWSEM_GENERIC_SPINLOCK
  31         bool
  32         default y
  33
  34 config GENERIC_CALIBRATE_DELAY
  35         bool
  36         default y
  37
  38 # Used in kernel/irq/manage.c and include/linux/irq.h
  39 config IRQ_RELEASE_METHOD
  40         bool
  41         default y
  42
  43 menu "UML-specific options"
  44
  45 config 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
  54 config 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
  66 config 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
  76 source "arch/um/Kconfig_arch"
  77 source "mm/Kconfig"
  78
  79 config LD_SCRIPT_STATIC
  80         bool
  81         default y
  82         depends on MODE_TT || STATIC_LINK
  83
  84 config LD_SCRIPT_DYN
  85         bool
  86         default y
  87         depends on !LD_SCRIPT_STATIC
  88
  89 config 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
 106 source "fs/Kconfig.binfmt"
 107
 108 config 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
 129 config 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
 147 config 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
 164 config 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
 183 config 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
 196 config 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
 220 config NR_CPUS
 221         int "Maximum number of CPUs (2-32)"
 222         range 2 32
 223         depends on SMP
 224         default "32"
 225
 226 config 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
 242 config 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
 251 config HIGHMEM
 252         bool "Highmem support"
 253         depends on !64BIT
 254
 255 config 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
 263 config 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
 274 endmenu
 275
 276 source "init/Kconfig"
 277
 278 source "net/Kconfig"
 279
 280 source "drivers/base/Kconfig"
 281
 282 source "arch/um/Kconfig_char"
 283
 284 source "drivers/block/Kconfig"
 285
 286 config NETDEVICES
 287         bool
 288         default NET
 289
 290 source "arch/um/Kconfig_net"
 291
 292 source "drivers/net/Kconfig"
 293
 294 source "fs/Kconfig"
 295
 296 source "security/Kconfig"
 297
 298 source "crypto/Kconfig"
 299
 300 source "lib/Kconfig"
 301
 302 menu "SCSI support"
 303 depends on BROKEN
 304
 305 config SCSI
 306         tristate "SCSI support"
 307
 308 # This gives us free_dma, which scsi.c wants.
 309 config GENERIC_ISA_DMA
 310         bool
 311         depends on SCSI
 312         default y
 313
 314 source "arch/um/Kconfig_scsi"
 315
 316 endmenu
 317
 318 source "drivers/md/Kconfig"
 319
 320 if BROKEN
 321         source "drivers/mtd/Kconfig"
 322 endif
 323
 324 #This is just to shut up some Kconfig warnings, so no prompt.
 325 config INPUT
 326         bool
 327         default n
 328
 329 source "arch/um/Kconfig.debug"