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 config MMU
  11         bool
  12         default y
  13
  14 mainmenu "Linux/Usermode Kernel Configuration"
  15
  16 config ISA
  17         bool
  18
  19 config SBUS
  20         bool
  21
  22 config PCI
  23         bool
  24
  25 config UID16
  26         bool
  27         default y
  28
  29 config GENERIC_CALIBRATE_DELAY
  30         bool
  31         default y
  32
  33 # Used in kernel/irq/manage.c and include/linux/irq.h
  34 config IRQ_RELEASE_METHOD
  35         bool
  36         default y
  37
  38 menu "Host processor type and features"
  39
  40 source "arch/i386/Kconfig.cpu"
  41
  42 endmenu
  43
  44 menu "UML-specific options"
  45
  46 config MODE_TT
  47         bool "Tracing thread support"
  48         default y
  49         help
  50         This option controls whether tracing thread support is compiled
  51         into UML.  Normally, this should be set to Y.  If you intend to
  52         use only skas mode (and the host has the skas patch applied to it),
  53         then it is OK to say N here.
  54
  55 config STATIC_LINK
  56         bool "Force a static link"
  57         default n
  58         depends on !MODE_TT
  59         help
  60         If CONFIG_MODE_TT is disabled, then this option gives you the ability
  61         to force a static link of UML.  Normally, if only skas mode is built
  62         in to UML, it will be linked as a shared binary.  This is inconvenient
  63         for use in a chroot jail.  So, if you intend to run UML inside a
  64         chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
  65         here.
  66
  67 config HOST_2G_2G
  68         bool "2G/2G host address space split"
  69         default n
  70         depends on MODE_TT
  71         help
  72         This is needed when the host on which you run has a 2G/2G memory
  73         split, instead of the customary 3G/1G.
  74
  75         Note that to enable such a host
  76         configuration, which makes sense only in some cases, you need special
  77         host patches.
  78
  79         So, if you do not know what to do here, say 'N'.
  80
  81 config KERNEL_HALF_GIGS
  82         int "Kernel address space size (in .5G units)"
  83         default "1"
  84         depends on MODE_TT
  85         help
  86         This determines the amount of address space that UML will allocate for
  87         its own, measured in half Gigabyte units.  The default is 1.
  88         Change this only if you need to boot UML with an unusually large amount
  89         of physical memory.
  90
  91 config MODE_SKAS
  92         bool "Separate Kernel Address Space support"
  93         default y
  94         help
  95         This option controls whether skas (separate kernel address space)
  96         support is compiled in.  If you have applied the skas patch to the
  97         host, then you certainly want to say Y here (and consider saying N
  98         to CONFIG_MODE_TT).  Otherwise, it is safe to say Y.  Disabling this
  99         option will shrink the UML binary slightly.
 100
 101 source "arch/um/Kconfig.arch"
 102 source "mm/Kconfig"
 103
 104 config LD_SCRIPT_STATIC
 105         bool
 106         default y
 107         depends on MODE_TT || STATIC_LINK
 108
 109 config LD_SCRIPT_DYN
 110         bool
 111         default y
 112         depends on !LD_SCRIPT_STATIC
 113
 114 config NET
 115         bool "Networking support"
 116         help
 117         Unless you really know what you are doing, you should say Y here.
 118         The reason is that some programs need kernel networking support even
 119         when running on a stand-alone machine that isn't connected to any
 120         other computer. If you are upgrading from an older kernel, you
 121         should consider updating your networking tools too because changes
 122         in the kernel and the tools often go hand in hand. The tools are
 123         contained in the package net-tools, the location and version number
 124         of which are given in <file:Documentation/Changes>.
 125
 126         For a general introduction to Linux networking, it is highly
 127         recommended to read the NET-HOWTO, available from
 128         <http://www.tldp.org/docs.html#howto>.
 129
 130
 131 source "fs/Kconfig.binfmt"
 132
 133 config HOSTFS
 134         tristate "Host filesystem"
 135         help
 136         While the User-Mode Linux port uses its own root file system for
 137         booting and normal file access, this module lets the UML user
 138         access files stored on the host.  It does not require any
 139         network connection between the Host and UML.  An example use of
 140         this might be:
 141
 142         mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
 143
 144         where /tmp/fromhost is an empty directory inside UML and
 145         /tmp/umlshare is a directory on the host with files the UML user
 146         wishes to access.
 147
 148         For more information, see
 149         <http://user-mode-linux.sourceforge.net/hostfs.html>.
 150
 151         If you'd like to be able to work with files stored on the host,
 152         say Y or M here; otherwise say N.
 153
 154 config HPPFS
 155         tristate "HoneyPot ProcFS (EXPERIMENTAL)"
 156         help
 157         hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
 158         entries to be overridden, removed, or fabricated from the host.
 159         Its purpose is to allow a UML to appear to be a physical machine
 160         by removing or changing anything in /proc which gives away the
 161         identity of a UML.
 162
 163         See <http://user-mode-linux.sf.net/hppfs.html> for more information.
 164
 165         You only need this if you are setting up a UML honeypot.  Otherwise,
 166         it is safe to say 'N' here.
 167
 168         If you are actively using it, please report any problems, since it's
 169         getting fixed. In this moment, it is experimental on 2.6 (it works on
 170         2.4).
 171
 172 config MCONSOLE
 173         bool "Management console"
 174         default y
 175         help
 176         The user mode linux management console is a low-level interface to
 177         the kernel, somewhat like the i386 SysRq interface.  Since there is
 178         a full-blown operating system running under every user mode linux
 179         instance, there is much greater flexibility possible than with the
 180         SysRq mechanism.
 181
 182         If you answer 'Y' to this option, to use this feature, you need the
 183         mconsole client (called uml_mconsole) which is present in CVS in
 184         2.4.5-9um and later (path /tools/mconsole), and is also in the
 185         distribution RPM package in 2.4.6 and later.
 186
 187         It is safe to say 'Y' here.
 188
 189 config MAGIC_SYSRQ
 190         bool "Magic SysRq key"
 191         depends on MCONSOLE
 192         ---help---
 193         If you say Y here, you will have some control over the system even
 194         if the system crashes for example during kernel debugging (e.g., you
 195         will be able to flush the buffer cache to disk, reboot the system
 196         immediately or dump some status information). A key for each of the
 197         possible requests is provided.
 198
 199         This is the feature normally accomplished by pressing a key
 200         while holding SysRq (Alt+PrintScreen).
 201
 202         On UML, this is accomplished by sending a "sysrq" command with
 203         mconsole, followed by the letter for the requested command.
 204
 205         The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 206         unless you really know what this hack does.
 207
 208 config SMP
 209         bool "Symmetric multi-processing support (EXPERIMENTAL)"
 210         default n
 211         #SMP_BROKEN is for x86_64.
 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"