arch/um/Kconfig

   1 config DEFCONFIG_LIST
   2         string
   3         option defconfig_list
   4         default "arch/$ARCH/defconfig"
   5
   6 # UML uses the generic IRQ sugsystem
   7 config GENERIC_HARDIRQS
   8         bool
   9         default y
  10
  11 config UML
  12         bool
  13         default y
  14
  15 config MMU
  16         bool
  17         default y
  18
  19 config NO_IOMEM
  20         def_bool y
  21
  22 mainmenu "Linux/Usermode Kernel Configuration"
  23
  24 config ISA
  25         bool
  26
  27 config SBUS
  28         bool
  29
  30 config PCI
  31         bool
  32
  33 config PCMCIA
  34         bool
  35
  36 # Yet to do!
  37 config TRACE_IRQFLAGS_SUPPORT
  38         bool
  39         default n
  40
  41 config LOCKDEP_SUPPORT
  42         bool
  43         default y
  44
  45 config STACKTRACE_SUPPORT
  46         bool
  47         default y
  48
  49 config GENERIC_CALIBRATE_DELAY
  50         bool
  51         default y
  52
  53 config GENERIC_BUG
  54         bool
  55         default y
  56         depends on BUG
  57
  58 # Used in kernel/irq/manage.c and include/linux/irq.h
  59 config IRQ_RELEASE_METHOD
  60         bool
  61         default y
  62
  63 menu "UML-specific options"
  64
  65 config MODE_TT
  66         bool "Tracing thread support (DEPRECATED)"
  67         default n
  68         depends on BROKEN
  69         help
  70         This option controls whether tracing thread support is compiled
  71         into UML. This option is largely obsolete, given that skas0 provides
  72         skas security and performance without needing to patch the host.
  73         It is safe to say 'N' here; saying 'Y' may cause additional problems
  74         with the resulting binary even if you run UML in SKAS mode, and running
  75         in TT mode is strongly *NOT RECOMMENDED*.
  76
  77 config STATIC_LINK
  78         bool "Force a static link"
  79         default n
  80         depends on !MODE_TT
  81         help
  82         If CONFIG_MODE_TT is disabled, then this option gives you the ability
  83         to force a static link of UML.  Normally, if only skas mode is built
  84         in to UML, it will be linked as a shared binary.  This is inconvenient
  85         for use in a chroot jail.  So, if you intend to run UML inside a
  86         chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
  87         here.
  88         Additionally, this option enables using higher memory spaces (up to
  89         2.75G) for UML - disabling CONFIG_MODE_TT and enabling this option leads
  90         to best results for this.
  91
  92 config KERNEL_HALF_GIGS
  93         int "Kernel address space size (in .5G units)"
  94         default "1"
  95         depends on MODE_TT
  96         help
  97         This determines the amount of address space that UML will allocate for
  98         its own, measured in half Gigabyte units.  The default is 1.
  99         Change this only if you need to boot UML with an unusually large amount
 100         of physical memory.
 101
 102 config MODE_SKAS
 103         bool "Separate Kernel Address Space support" if MODE_TT
 104         default y
 105         help
 106         This option controls whether skas (separate kernel address space)
 107         support is compiled in.
 108         Unless you have specific needs to use TT mode (which applies almost only
 109         to developers), you should say Y here.
 110         SKAS mode will make use of the SKAS3 patch if it is applied on the host
 111         (and your UML will run in SKAS3 mode), but if no SKAS patch is applied
 112         on the host it will run in SKAS0 mode, which is anyway faster than TT
 113         mode.
 114
 115 source "arch/um/Kconfig.arch"
 116 source "mm/Kconfig"
 117
 118 config LD_SCRIPT_STATIC
 119         bool
 120         default y
 121         depends on MODE_TT || STATIC_LINK
 122
 123 config LD_SCRIPT_DYN
 124         bool
 125         default y
 126         depends on !LD_SCRIPT_STATIC
 127
 128 config NET
 129         bool "Networking support"
 130         help
 131         Unless you really know what you are doing, you should say Y here.
 132         The reason is that some programs need kernel networking support even
 133         when running on a stand-alone machine that isn't connected to any
 134         other computer. If you are upgrading from an older kernel, you
 135         should consider updating your networking tools too because changes
 136         in the kernel and the tools often go hand in hand. The tools are
 137         contained in the package net-tools, the location and version number
 138         of which are given in <file:Documentation/Changes>.
 139
 140         For a general introduction to Linux networking, it is highly
 141         recommended to read the NET-HOWTO, available from
 142         <http://www.tldp.org/docs.html#howto>.
 143
 144
 145 source "fs/Kconfig.binfmt"
 146
 147 config HOSTFS
 148         tristate "Host filesystem"
 149         help
 150         While the User-Mode Linux port uses its own root file system for
 151         booting and normal file access, this module lets the UML user
 152         access files stored on the host.  It does not require any
 153         network connection between the Host and UML.  An example use of
 154         this might be:
 155
 156         mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
 157
 158         where /tmp/fromhost is an empty directory inside UML and
 159         /tmp/umlshare is a directory on the host with files the UML user
 160         wishes to access.
 161
 162         For more information, see
 163         <http://user-mode-linux.sourceforge.net/hostfs.html>.
 164
 165         If you'd like to be able to work with files stored on the host,
 166         say Y or M here; otherwise say N.
 167
 168 config HPPFS
 169         tristate "HoneyPot ProcFS (EXPERIMENTAL)"
 170         depends on EXPERIMENTAL
 171         help
 172         hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
 173         entries to be overridden, removed, or fabricated from the host.
 174         Its purpose is to allow a UML to appear to be a physical machine
 175         by removing or changing anything in /proc which gives away the
 176         identity of a UML.
 177
 178         See <http://user-mode-linux.sf.net/hppfs.html> for more information.
 179
 180         You only need this if you are setting up a UML honeypot.  Otherwise,
 181         it is safe to say 'N' here.
 182
 183 config MCONSOLE
 184         bool "Management console"
 185         default y
 186         help
 187         The user mode linux management console is a low-level interface to
 188         the kernel, somewhat like the i386 SysRq interface.  Since there is
 189         a full-blown operating system running under every user mode linux
 190         instance, there is much greater flexibility possible than with the
 191         SysRq mechanism.
 192
 193         If you answer 'Y' to this option, to use this feature, you need the
 194         mconsole client (called uml_mconsole) which is present in CVS in
 195         2.4.5-9um and later (path /tools/mconsole), and is also in the
 196         distribution RPM package in 2.4.6 and later.
 197
 198         It is safe to say 'Y' here.
 199
 200 config MAGIC_SYSRQ
 201         bool "Magic SysRq key"
 202         depends on MCONSOLE
 203         ---help---
 204         If you say Y here, you will have some control over the system even
 205         if the system crashes for example during kernel debugging (e.g., you
 206         will be able to flush the buffer cache to disk, reboot the system
 207         immediately or dump some status information). A key for each of the
 208         possible requests is provided.
 209
 210         This is the feature normally accomplished by pressing a key
 211         while holding SysRq (Alt+PrintScreen).
 212
 213         On UML, this is accomplished by sending a "sysrq" command with
 214         mconsole, followed by the letter for the requested command.
 215
 216         The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 217         unless you really know what this hack does.
 218
 219 config SMP
 220         bool "Symmetric multi-processing support (EXPERIMENTAL)"
 221         default n
 222         #SMP_BROKEN is for x86_64.
 223         depends on MODE_TT && EXPERIMENTAL && (!SMP_BROKEN || (BROKEN && SMP_BROKEN))
 224         help
 225         This option enables UML SMP support.
 226         It is NOT related to having a real SMP box. Not directly, at least.
 227
 228         UML implements virtual SMP by allowing as many processes to run
 229         simultaneously on the host as there are virtual processors configured.
 230
 231         Obviously, if the host is a uniprocessor, those processes will
 232         timeshare, but, inside UML, will appear to be running simultaneously.
 233         If the host is a multiprocessor, then UML processes may run
 234         simultaneously, depending on the host scheduler.
 235
 236         This, however, is supported only in TT mode. So, if you use the SKAS
 237         patch on your host, switching to TT mode and enabling SMP usually gives
 238         you worse performances.
 239         Also, since the support for SMP has been under-developed, there could
 240         be some bugs being exposed by enabling SMP.
 241
 242         If you don't know what to do, say N.
 243
 244 config NR_CPUS
 245         int "Maximum number of CPUs (2-32)"
 246         range 2 32
 247         depends on SMP
 248         default "32"
 249
 250 config NEST_LEVEL
 251         int "Nesting level"
 252         default "0"
 253         help
 254         This is set to the number of layers of UMLs that this UML will be run
 255         in.  Normally, this is zero, meaning that it will run directly on the
 256         host.  Setting it to one will build a UML that can run inside a UML
 257         that is running on the host.  Generally, if you intend this UML to run
 258         inside another UML, set CONFIG_NEST_LEVEL to one more than the host
 259         UML.
 260
 261         Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
 262         greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
 263         set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
 264         Only change this if you are running nested UMLs.
 265
 266 config HIGHMEM
 267         bool "Highmem support (EXPERIMENTAL)"
 268         depends on !64BIT && EXPERIMENTAL
 269         default n
 270         help
 271         This was used to allow UML to run with big amounts of memory.
 272         Currently it is unstable, so if unsure say N.
 273
 274         To use big amounts of memory, it is recommended to disable TT mode (i.e.
 275         CONFIG_MODE_TT) and enable static linking (i.e. CONFIG_STATIC_LINK) -
 276         this should allow the guest to use up to 2.75G of memory.
 277
 278 config KERNEL_STACK_ORDER
 279         int "Kernel stack size order"
 280         default 2
 281         help
 282         This option determines the size of UML kernel stacks.  They will
 283         be 1 << order pages.  The default is OK unless you're running Valgrind
 284         on UML, in which case, set this to 3.
 285
 286 config UML_REAL_TIME_CLOCK
 287         bool "Real-time Clock"
 288         default y
 289         help
 290         This option makes UML time deltas match wall clock deltas.  This should
 291         normally be enabled.  The exception would be if you are debugging with
 292         UML and spend long times with UML stopped at a breakpoint.  In this
 293         case, when UML is restarted, it will call the timer enough times to make
 294         up for the time spent at the breakpoint.  This could result in a
 295         noticeable lag.  If this is a problem, then disable this option.
 296
 297 endmenu
 298
 299 source "init/Kconfig"
 300
 301 source "drivers/block/Kconfig"
 302
 303 source "arch/um/Kconfig.char"
 304
 305 source "drivers/base/Kconfig"
 306
 307 source "net/Kconfig"
 308
 309 source "arch/um/Kconfig.net"
 310
 311 source "drivers/net/Kconfig"
 312
 313 source "drivers/connector/Kconfig"
 314
 315 source "fs/Kconfig"
 316
 317 source "security/Kconfig"
 318
 319 source "crypto/Kconfig"
 320
 321 source "lib/Kconfig"
 322
 323 menu "SCSI support"
 324 depends on BROKEN
 325
 326 config SCSI
 327         tristate "SCSI support"
 328
 329 # This gives us free_dma, which scsi.c wants.
 330 config GENERIC_ISA_DMA
 331         bool
 332         depends on SCSI
 333         default y
 334
 335 source "arch/um/Kconfig.scsi"
 336
 337 endmenu
 338
 339 source "drivers/md/Kconfig"
 340
 341 if BROKEN
 342         source "drivers/mtd/Kconfig"
 343 endif
 344
 345 #This is just to shut up some Kconfig warnings, so no prompt.
 346 config INPUT
 347         bool
 348         default n
 349
 350 source "arch/um/Kconfig.debug"