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