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 "Host processor type and features"
  44
  45 source "arch/i386/Kconfig.cpu"
  46
  47 endmenu
  48
  49 menu "UML-specific options"
  50
  51 config MODE_TT
  52         bool "Tracing thread support"
  53         default y
  54         help
  55         This option controls whether tracing thread support is compiled
  56         into UML.  Normally, this should be set to Y.  If you intend to
  57         use only skas mode (and the host has the skas patch applied to it),
  58         then it is OK to say N here.
  59
  60 config STATIC_LINK
  61         bool "Force a static link"
  62         default n
  63         depends on !MODE_TT
  64         help
  65         If CONFIG_MODE_TT is disabled, then this option gives you the ability
  66         to force a static link of UML.  Normally, if only skas mode is built
  67         in to UML, it will be linked as a shared binary.  This is inconvenient
  68         for use in a chroot jail.  So, if you intend to run UML inside a
  69         chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
  70         here.
  71
  72 config MODE_SKAS
  73         bool "Separate Kernel Address Space support"
  74         default y
  75         help
  76         This option controls whether skas (separate kernel address space)
  77         support is compiled in.  If you have applied the skas patch to the
  78         host, then you certainly want to say Y here (and consider saying N
  79         to CONFIG_MODE_TT).  Otherwise, it is safe to say Y.  Disabling this
  80         option will shrink the UML binary slightly.
  81
  82 source "arch/um/Kconfig.arch"
  83 source "mm/Kconfig"
  84
  85 config LD_SCRIPT_STATIC
  86         bool
  87         default y
  88         depends on MODE_TT || STATIC_LINK
  89
  90 config LD_SCRIPT_DYN
  91         bool
  92         default y
  93         depends on !LD_SCRIPT_STATIC
  94
  95 config NET
  96         bool "Networking support"
  97         help
  98         Unless you really know what you are doing, you should say Y here.
  99         The reason is that some programs need kernel networking support even
 100         when running on a stand-alone machine that isn't connected to any
 101         other computer. If you are upgrading from an older kernel, you
 102         should consider updating your networking tools too because changes
 103         in the kernel and the tools often go hand in hand. The tools are
 104         contained in the package net-tools, the location and version number
 105         of which are given in <file:Documentation/Changes>.
 106
 107         For a general introduction to Linux networking, it is highly
 108         recommended to read the NET-HOWTO, available from
 109         <http://www.tldp.org/docs.html#howto>.
 110
 111
 112 source "fs/Kconfig.binfmt"
 113
 114 config HOSTFS
 115         tristate "Host filesystem"
 116         help
 117         While the User-Mode Linux port uses its own root file system for
 118         booting and normal file access, this module lets the UML user
 119         access files stored on the host.  It does not require any
 120         network connection between the Host and UML.  An example use of
 121         this might be:
 122
 123         mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
 124
 125         where /tmp/fromhost is an empty directory inside UML and
 126         /tmp/umlshare is a directory on the host with files the UML user
 127         wishes to access.
 128
 129         For more information, see
 130         <http://user-mode-linux.sourceforge.net/hostfs.html>.
 131
 132         If you'd like to be able to work with files stored on the host,
 133         say Y or M here; otherwise say N.
 134
 135 config HPPFS
 136         tristate "HoneyPot ProcFS (EXPERIMENTAL)"
 137         help
 138         hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
 139         entries to be overridden, removed, or fabricated from the host.
 140         Its purpose is to allow a UML to appear to be a physical machine
 141         by removing or changing anything in /proc which gives away the
 142         identity of a UML.
 143
 144         See <http://user-mode-linux.sf.net/hppfs.html> for more information.
 145
 146         You only need this if you are setting up a UML honeypot.  Otherwise,
 147         it is safe to say 'N' here.
 148
 149         If you are actively using it, please report any problems, since it's
 150         getting fixed. In this moment, it is experimental on 2.6 (it works on
 151         2.4).
 152
 153 config MCONSOLE
 154         bool "Management console"
 155         default y
 156         help
 157         The user mode linux management console is a low-level interface to
 158         the kernel, somewhat like the i386 SysRq interface.  Since there is
 159         a full-blown operating system running under every user mode linux
 160         instance, there is much greater flexibility possible than with the
 161         SysRq mechanism.
 162
 163         If you answer 'Y' to this option, to use this feature, you need the
 164         mconsole client (called uml_mconsole) which is present in CVS in
 165         2.4.5-9um and later (path /tools/mconsole), and is also in the
 166         distribution RPM package in 2.4.6 and later.
 167
 168         It is safe to say 'Y' here.
 169
 170 config MAGIC_SYSRQ
 171         bool "Magic SysRq key"
 172         depends on MCONSOLE
 173         ---help---
 174         If you say Y here, you will have some control over the system even
 175         if the system crashes for example during kernel debugging (e.g., you
 176         will be able to flush the buffer cache to disk, reboot the system
 177         immediately or dump some status information). A key for each of the
 178         possible requests is provided.
 179
 180         This is the feature normally accomplished by pressing a key
 181         while holding SysRq (Alt+PrintScreen).
 182
 183         On UML, this is accomplished by sending a "sysrq" command with
 184         mconsole, followed by the letter for the requested command.
 185
 186         The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 187         unless you really know what this hack does.
 188
 189 config HOST_2G_2G
 190         bool "2G/2G host address space split"
 191         default n
 192         help
 193         This is needed when the host on which you run has a 2G/2G memory
 194         split, instead of the customary 3G/1G.
 195
 196         Note that to enable such a host
 197         configuration, which makes sense only in some cases, you need special
 198         host patches.
 199
 200         So, if you do not know what to do here, say 'N'.
 201
 202 config SMP
 203         bool "Symmetric multi-processing support (EXPERIMENTAL)"
 204         default n
 205         depends on (MODE_TT && EXPERIMENTAL && !SMP_BROKEN) || (BROKEN && SMP_BROKEN)
 206         help
 207         This option enables UML SMP support.
 208         It is NOT related to having a real SMP box. Not directly, at least.
 209
 210         UML implements virtual SMP by allowing as many processes to run
 211         simultaneously on the host as there are virtual processors configured.
 212
 213         Obviously, if the host is a uniprocessor, those processes will
 214         timeshare, but, inside UML, will appear to be running simultaneously.
 215         If the host is a multiprocessor, then UML processes may run
 216         simultaneously, depending on the host scheduler.
 217
 218         This, however, is supported only in TT mode. So, if you use the SKAS
 219         patch on your host, switching to TT mode and enabling SMP usually gives
 220         you worse performances.
 221         Also, since the support for SMP has been under-developed, there could
 222         be some bugs being exposed by enabling SMP.
 223
 224         If you don't know what to do, say N.
 225
 226 config NR_CPUS
 227         int "Maximum number of CPUs (2-32)"
 228         range 2 32
 229         depends on SMP
 230         default "32"
 231
 232 config NEST_LEVEL
 233         int "Nesting level"
 234         default "0"
 235         help
 236         This is set to the number of layers of UMLs that this UML will be run
 237         in.  Normally, this is zero, meaning that it will run directly on the
 238         host.  Setting it to one will build a UML that can run inside a UML
 239         that is running on the host.  Generally, if you intend this UML to run
 240         inside another UML, set CONFIG_NEST_LEVEL to one more than the host
 241         UML.
 242
 243         Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
 244         greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
 245         set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
 246         Only change this if you are running nested UMLs.
 247
 248 config KERNEL_HALF_GIGS
 249         int "Kernel address space size (in .5G units)"
 250         default "1"
 251         help
 252         This determines the amount of address space that UML will allocate for
 253         its own, measured in half Gigabyte units.  The default is 1.
 254         Change this only if you need to boot UML with an unusually large amount
 255         of physical memory.
 256
 257 config HIGHMEM
 258         bool "Highmem support"
 259         depends on !64BIT
 260
 261 config KERNEL_STACK_ORDER
 262         int "Kernel stack size order"
 263         default 2
 264         help
 265         This option determines the size of UML kernel stacks.  They will
 266         be 1 << order pages.  The default is OK unless you're running Valgrind
 267         on UML, in which case, set this to 3.
 268
 269 config UML_REAL_TIME_CLOCK
 270         bool "Real-time Clock"
 271         default y
 272         help
 273         This option makes UML time deltas match wall clock deltas.  This should
 274         normally be enabled.  The exception would be if you are debugging with
 275         UML and spend long times with UML stopped at a breakpoint.  In this
 276         case, when UML is restarted, it will call the timer enough times to make
 277         up for the time spent at the breakpoint.  This could result in a
 278         noticable lag.  If this is a problem, then disable this option.
 279
 280 endmenu
 281
 282 source "init/Kconfig"
 283
 284 source "net/Kconfig"
 285
 286 source "drivers/base/Kconfig"
 287
 288 source "arch/um/Kconfig.char"
 289
 290 source "drivers/block/Kconfig"
 291
 292 config NETDEVICES
 293         bool
 294         default NET
 295
 296 source "arch/um/Kconfig.net"
 297
 298 source "drivers/net/Kconfig"
 299
 300 source "fs/Kconfig"
 301
 302 source "security/Kconfig"
 303
 304 source "crypto/Kconfig"
 305
 306 source "lib/Kconfig"
 307
 308 menu "SCSI support"
 309 depends on BROKEN
 310
 311 config SCSI
 312         tristate "SCSI support"
 313
 314 # This gives us free_dma, which scsi.c wants.
 315 config GENERIC_ISA_DMA
 316         bool
 317         depends on SCSI
 318         default y
 319
 320 source "arch/um/Kconfig.scsi"
 321
 322 endmenu
 323
 324 source "drivers/md/Kconfig"
 325
 326 if BROKEN
 327         source "drivers/mtd/Kconfig"
 328 endif
 329
 330 #This is just to shut up some Kconfig warnings, so no prompt.
 331 config INPUT
 332         bool
 333         default n
 334
 335 source "arch/um/Kconfig.debug"