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 HOST_2G_2G
  69         bool "2G/2G host address space split"
  70         default n
  71         depends on MODE_TT
  72         help
  73         This is needed when the host on which you run has a 2G/2G memory
  74         split, instead of the customary 3G/1G.
  75
  76         Note that to enable such a host
  77         configuration, which makes sense only in some cases, you need special
  78         host patches.
  79
  80         So, if you do not know what to do here, say 'N'.
  81
  82 config KERNEL_HALF_GIGS
  83         int "Kernel address space size (in .5G units)"
  84         default "1"
  85         depends on MODE_TT
  86         help
  87         This determines the amount of address space that UML will allocate for
  88         its own, measured in half Gigabyte units.  The default is 1.
  89         Change this only if you need to boot UML with an unusually large amount
  90         of physical memory.
  91
  92 config MODE_SKAS
  93         bool "Separate Kernel Address Space support"
  94         default y
  95         help
  96         This option controls whether skas (separate kernel address space)
  97         support is compiled in.  If you have applied the skas patch to the
  98         host, then you certainly want to say Y here (and consider saying N
  99         to CONFIG_MODE_TT).  Otherwise, it is safe to say Y.  Disabling this
 100         option will shrink the UML binary slightly.
 101
 102 source "arch/um/Kconfig.arch"
 103 source "mm/Kconfig"
 104
 105 config LD_SCRIPT_STATIC
 106         bool
 107         default y
 108         depends on MODE_TT || STATIC_LINK
 109
 110 config LD_SCRIPT_DYN
 111         bool
 112         default y
 113         depends on !LD_SCRIPT_STATIC
 114
 115 config NET
 116         bool "Networking support"
 117         help
 118         Unless you really know what you are doing, you should say Y here.
 119         The reason is that some programs need kernel networking support even
 120         when running on a stand-alone machine that isn't connected to any
 121         other computer. If you are upgrading from an older kernel, you
 122         should consider updating your networking tools too because changes
 123         in the kernel and the tools often go hand in hand. The tools are
 124         contained in the package net-tools, the location and version number
 125         of which are given in <file:Documentation/Changes>.
 126
 127         For a general introduction to Linux networking, it is highly
 128         recommended to read the NET-HOWTO, available from
 129         <http://www.tldp.org/docs.html#howto>.
 130
 131
 132 source "fs/Kconfig.binfmt"
 133
 134 config HOSTFS
 135         tristate "Host filesystem"
 136         help
 137         While the User-Mode Linux port uses its own root file system for
 138         booting and normal file access, this module lets the UML user
 139         access files stored on the host.  It does not require any
 140         network connection between the Host and UML.  An example use of
 141         this might be:
 142
 143         mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
 144
 145         where /tmp/fromhost is an empty directory inside UML and
 146         /tmp/umlshare is a directory on the host with files the UML user
 147         wishes to access.
 148
 149         For more information, see
 150         <http://user-mode-linux.sourceforge.net/hostfs.html>.
 151
 152         If you'd like to be able to work with files stored on the host,
 153         say Y or M here; otherwise say N.
 154
 155 config HPPFS
 156         tristate "HoneyPot ProcFS (EXPERIMENTAL)"
 157         help
 158         hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
 159         entries to be overridden, removed, or fabricated from the host.
 160         Its purpose is to allow a UML to appear to be a physical machine
 161         by removing or changing anything in /proc which gives away the
 162         identity of a UML.
 163
 164         See <http://user-mode-linux.sf.net/hppfs.html> for more information.
 165
 166         You only need this if you are setting up a UML honeypot.  Otherwise,
 167         it is safe to say 'N' here.
 168
 169         If you are actively using it, please report any problems, since it's
 170         getting fixed. In this moment, it is experimental on 2.6 (it works on
 171         2.4).
 172
 173 config MCONSOLE
 174         bool "Management console"
 175         default y
 176         help
 177         The user mode linux management console is a low-level interface to
 178         the kernel, somewhat like the i386 SysRq interface.  Since there is
 179         a full-blown operating system running under every user mode linux
 180         instance, there is much greater flexibility possible than with the
 181         SysRq mechanism.
 182
 183         If you answer 'Y' to this option, to use this feature, you need the
 184         mconsole client (called uml_mconsole) which is present in CVS in
 185         2.4.5-9um and later (path /tools/mconsole), and is also in the
 186         distribution RPM package in 2.4.6 and later.
 187
 188         It is safe to say 'Y' here.
 189
 190 config MAGIC_SYSRQ
 191         bool "Magic SysRq key"
 192         depends on MCONSOLE
 193         ---help---
 194         If you say Y here, you will have some control over the system even
 195         if the system crashes for example during kernel debugging (e.g., you
 196         will be able to flush the buffer cache to disk, reboot the system
 197         immediately or dump some status information). A key for each of the
 198         possible requests is provided.
 199
 200         This is the feature normally accomplished by pressing a key
 201         while holding SysRq (Alt+PrintScreen).
 202
 203         On UML, this is accomplished by sending a "sysrq" command with
 204         mconsole, followed by the letter for the requested command.
 205
 206         The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 207         unless you really know what this hack does.
 208
 209 config SMP
 210         bool "Symmetric multi-processing support (EXPERIMENTAL)"
 211         default n
 212         depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
 213         help
 214         This option enables UML SMP support.
 215         It is NOT related to having a real SMP box. Not directly, at least.
 216
 217         UML implements virtual SMP by allowing as many processes to run
 218         simultaneously on the host as there are virtual processors configured.
 219
 220         Obviously, if the host is a uniprocessor, those processes will
 221         timeshare, but, inside UML, will appear to be running simultaneously.
 222         If the host is a multiprocessor, then UML processes may run
 223         simultaneously, depending on the host scheduler.
 224
 225         This, however, is supported only in TT mode. So, if you use the SKAS
 226         patch on your host, switching to TT mode and enabling SMP usually gives
 227         you worse performances.
 228         Also, since the support for SMP has been under-developed, there could
 229         be some bugs being exposed by enabling SMP.
 230
 231         If you don't know what to do, say N.
 232
 233 config NR_CPUS
 234         int "Maximum number of CPUs (2-32)"
 235         range 2 32
 236         depends on SMP
 237         default "32"
 238
 239 config NEST_LEVEL
 240         int "Nesting level"
 241         default "0"
 242         help
 243         This is set to the number of layers of UMLs that this UML will be run
 244         in.  Normally, this is zero, meaning that it will run directly on the
 245         host.  Setting it to one will build a UML that can run inside a UML
 246         that is running on the host.  Generally, if you intend this UML to run
 247         inside another UML, set CONFIG_NEST_LEVEL to one more than the host
 248         UML.
 249
 250         Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
 251         greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
 252         set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
 253         Only change this if you are running nested UMLs.
 254
 255 config HIGHMEM
 256         bool "Highmem support"
 257         depends on !64BIT
 258
 259 config KERNEL_STACK_ORDER
 260         int "Kernel stack size order"
 261         default 2
 262         help
 263         This option determines the size of UML kernel stacks.  They will
 264         be 1 << order pages.  The default is OK unless you're running Valgrind
 265         on UML, in which case, set this to 3.
 266
 267 config UML_REAL_TIME_CLOCK
 268         bool "Real-time Clock"
 269         default y
 270         help
 271         This option makes UML time deltas match wall clock deltas.  This should
 272         normally be enabled.  The exception would be if you are debugging with
 273         UML and spend long times with UML stopped at a breakpoint.  In this
 274         case, when UML is restarted, it will call the timer enough times to make
 275         up for the time spent at the breakpoint.  This could result in a
 276         noticable lag.  If this is a problem, then disable this option.
 277
 278 endmenu
 279
 280 source "init/Kconfig"
 281
 282 source "net/Kconfig"
 283
 284 source "drivers/base/Kconfig"
 285
 286 source "arch/um/Kconfig.char"
 287
 288 source "drivers/block/Kconfig"
 289
 290 config NETDEVICES
 291         bool
 292         default NET
 293
 294 source "arch/um/Kconfig.net"
 295
 296 source "drivers/net/Kconfig"
 297
 298 source "fs/Kconfig"
 299
 300 source "security/Kconfig"
 301
 302 source "crypto/Kconfig"
 303
 304 source "lib/Kconfig"
 305
 306 menu "SCSI support"
 307 depends on BROKEN
 308
 309 config SCSI
 310         tristate "SCSI support"
 311
 312 # This gives us free_dma, which scsi.c wants.
 313 config GENERIC_ISA_DMA
 314         bool
 315         depends on SCSI
 316         default y
 317
 318 source "arch/um/Kconfig.scsi"
 319
 320 endmenu
 321
 322 source "drivers/md/Kconfig"
 323
 324 if BROKEN
 325         source "drivers/mtd/Kconfig"
 326 endif
 327
 328 #This is just to shut up some Kconfig warnings, so no prompt.
 329 config INPUT
 330         bool
 331         default n
 332
 333 source "arch/um/Kconfig.debug"