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 GENERIC_CALIBRATE_DELAY
  31         bool
  32         default y
  33
  34 # Used in kernel/irq/manage.c and include/linux/irq.h
  35 config IRQ_RELEASE_METHOD
  36         bool
  37         default y
  38
  39 menu "Host processor type and features"
  40
  41 source "arch/i386/Kconfig.cpu"
  42
  43 endmenu
  44
  45 menu "UML-specific options"
  46
  47 config MODE_TT
  48         bool "Tracing thread support"
  49         default y
  50         help
  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.
  55
  56 config STATIC_LINK
  57         bool "Force a static link"
  58         default n
  59         depends on !MODE_TT
  60         help
  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
  66         here.
  67
  68 config MODE_SKAS
  69         bool "Separate Kernel Address Space support"
  70         default y
  71         help
  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.
  77
  78 source "arch/um/Kconfig.arch"
  79 source "mm/Kconfig"
  80
  81 config LD_SCRIPT_STATIC
  82         bool
  83         default y
  84         depends on MODE_TT || STATIC_LINK
  85
  86 config LD_SCRIPT_DYN
  87         bool
  88         default y
  89         depends on !LD_SCRIPT_STATIC
  90
  91 config NET
  92         bool "Networking support"
  93         help
  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>.
 102
 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>.
 106
 107
 108 source "fs/Kconfig.binfmt"
 109
 110 config HOSTFS
 111         tristate "Host filesystem"
 112         help
 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
 117         this might be:
 118
 119         mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
 120
 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
 123         wishes to access.
 124
 125         For more information, see
 126         <http://user-mode-linux.sourceforge.net/hostfs.html>.
 127
 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.
 130
 131 config HPPFS
 132         tristate "HoneyPot ProcFS (EXPERIMENTAL)"
 133         help
 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
 138         identity of a UML.
 139
 140         See <http://user-mode-linux.sf.net/hppfs.html> for more information.
 141
 142         You only need this if you are setting up a UML honeypot.  Otherwise,
 143         it is safe to say 'N' here.
 144
 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
 147         2.4).
 148
 149 config MCONSOLE
 150         bool "Management console"
 151         default y
 152         help
 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
 157         SysRq mechanism.
 158
 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.
 163
 164         It is safe to say 'Y' here.
 165
 166 config MAGIC_SYSRQ
 167         bool "Magic SysRq key"
 168         depends on MCONSOLE
 169         ---help---
 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.
 175
 176         This is the feature normally accomplished by pressing a key
 177         while holding SysRq (Alt+PrintScreen).
 178
 179         On UML, this is accomplished by sending a "sysrq" command with
 180         mconsole, followed by the letter for the requested command.
 181
 182         The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 183         unless you really know what this hack does.
 184
 185 config HOST_2G_2G
 186         bool "2G/2G host address space split"
 187         default n
 188         help
 189         This is needed when the host on which you run has a 2G/2G memory
 190         split, instead of the customary 3G/1G.
 191
 192         Note that to enable such a host
 193         configuration, which makes sense only in some cases, you need special
 194         host patches.
 195
 196         So, if you do not know what to do here, say 'N'.
 197
 198 config SMP
 199         bool "Symmetric multi-processing support (EXPERIMENTAL)"
 200         default n
 201         depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
 202         help
 203         This option enables UML SMP support.
 204         It is NOT related to having a real SMP box. Not directly, at least.
 205
 206         UML implements virtual SMP by allowing as many processes to run
 207         simultaneously on the host as there are virtual processors configured.
 208
 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.
 213
 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.
 219
 220         If you don't know what to do, say N.
 221
 222 config NR_CPUS
 223         int "Maximum number of CPUs (2-32)"
 224         range 2 32
 225         depends on SMP
 226         default "32"
 227
 228 config NEST_LEVEL
 229         int "Nesting level"
 230         default "0"
 231         help
 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
 237         UML.
 238
 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.
 243
 244 config KERNEL_HALF_GIGS
 245         int "Kernel address space size (in .5G units)"
 246         default "1"
 247         help
 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
 251         of physical memory.
 252
 253 config HIGHMEM
 254         bool "Highmem support"
 255         depends on !64BIT
 256
 257 config KERNEL_STACK_ORDER
 258         int "Kernel stack size order"
 259         default 2
 260         help
 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.
 264
 265 config UML_REAL_TIME_CLOCK
 266         bool "Real-time Clock"
 267         default y
 268         help
 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.
 275
 276 endmenu
 277
 278 source "init/Kconfig"
 279
 280 source "net/Kconfig"
 281
 282 source "drivers/base/Kconfig"
 283
 284 source "arch/um/Kconfig.char"
 285
 286 source "drivers/block/Kconfig"
 287
 288 config NETDEVICES
 289         bool
 290         default NET
 291
 292 source "arch/um/Kconfig.net"
 293
 294 source "drivers/net/Kconfig"
 295
 296 source "fs/Kconfig"
 297
 298 source "security/Kconfig"
 299
 300 source "crypto/Kconfig"
 301
 302 source "lib/Kconfig"
 303
 304 menu "SCSI support"
 305 depends on BROKEN
 306
 307 config SCSI
 308         tristate "SCSI support"
 309
 310 # This gives us free_dma, which scsi.c wants.
 311 config GENERIC_ISA_DMA
 312         bool
 313         depends on SCSI
 314         default y
 315
 316 source "arch/um/Kconfig.scsi"
 317
 318 endmenu
 319
 320 source "drivers/md/Kconfig"
 321
 322 if BROKEN
 323         source "drivers/mtd/Kconfig"
 324 endif
 325
 326 #This is just to shut up some Kconfig warnings, so no prompt.
 327 config INPUT
 328         bool
 329         default n
 330
 331 source "arch/um/Kconfig.debug"