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 PCMCIA
  26         bool
  27
  28 # Yet to do!
  29 config TRACE_IRQFLAGS_SUPPORT
  30         bool
  31         default n
  32
  33 config LOCKDEP_SUPPORT
  34         bool
  35         default y
  36
  37 config STACKTRACE_SUPPORT
  38         bool
  39         default y
  40
  41 config GENERIC_CALIBRATE_DELAY
  42         bool
  43         default y
  44
  45 # Used in kernel/irq/manage.c and include/linux/irq.h
  46 config IRQ_RELEASE_METHOD
  47         bool
  48         default y
  49
  50 menu "UML-specific options"
  51
  52 config MODE_TT
  53         bool "Tracing thread support (DEPRECATED)"
  54         default n
  55         help
  56         This option controls whether tracing thread support is compiled
  57         into UML. This option is largely obsolete, given that skas0 provides
  58         skas security and performance without needing to patch the host.
  59         It is safe to say 'N' here; saying 'Y' may cause additional problems
  60         with the resulting binary even if you run UML in SKAS mode, and running
  61         in TT mode is strongly *NOT RECOMMENDED*.
  62
  63 config STATIC_LINK
  64         bool "Force a static link"
  65         default n
  66         depends on !MODE_TT
  67         help
  68         If CONFIG_MODE_TT is disabled, then this option gives you the ability
  69         to force a static link of UML.  Normally, if only skas mode is built
  70         in to UML, it will be linked as a shared binary.  This is inconvenient
  71         for use in a chroot jail.  So, if you intend to run UML inside a
  72         chroot, and you disable CONFIG_MODE_TT, you probably want to say Y
  73         here.
  74         Additionally, this option enables using higher memory spaces (up to
  75         2.75G) for UML - disabling CONFIG_MODE_TT and enabling this option leads
  76         to best results for this.
  77
  78 config KERNEL_HALF_GIGS
  79         int "Kernel address space size (in .5G units)"
  80         default "1"
  81         depends on MODE_TT
  82         help
  83         This determines the amount of address space that UML will allocate for
  84         its own, measured in half Gigabyte units.  The default is 1.
  85         Change this only if you need to boot UML with an unusually large amount
  86         of physical memory.
  87
  88 config MODE_SKAS
  89         bool "Separate Kernel Address Space support" if MODE_TT
  90         default y
  91         help
  92         This option controls whether skas (separate kernel address space)
  93         support is compiled in.
  94         Unless you have specific needs to use TT mode (which applies almost only
  95         to developers), you should say Y here.
  96         SKAS mode will make use of the SKAS3 patch if it is applied on the host
  97         (and your UML will run in SKAS3 mode), but if no SKAS patch is applied
  98         on the host it will run in SKAS0 mode, which is anyway faster than TT
  99         mode.
 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         depends on 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 config MCONSOLE
 170         bool "Management console"
 171         default y
 172         help
 173         The user mode linux management console is a low-level interface to
 174         the kernel, somewhat like the i386 SysRq interface.  Since there is
 175         a full-blown operating system running under every user mode linux
 176         instance, there is much greater flexibility possible than with the
 177         SysRq mechanism.
 178
 179         If you answer 'Y' to this option, to use this feature, you need the
 180         mconsole client (called uml_mconsole) which is present in CVS in
 181         2.4.5-9um and later (path /tools/mconsole), and is also in the
 182         distribution RPM package in 2.4.6 and later.
 183
 184         It is safe to say 'Y' here.
 185
 186 config MAGIC_SYSRQ
 187         bool "Magic SysRq key"
 188         depends on MCONSOLE
 189         ---help---
 190         If you say Y here, you will have some control over the system even
 191         if the system crashes for example during kernel debugging (e.g., you
 192         will be able to flush the buffer cache to disk, reboot the system
 193         immediately or dump some status information). A key for each of the
 194         possible requests is provided.
 195
 196         This is the feature normally accomplished by pressing a key
 197         while holding SysRq (Alt+PrintScreen).
 198
 199         On UML, this is accomplished by sending a "sysrq" command with
 200         mconsole, followed by the letter for the requested command.
 201
 202         The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
 203         unless you really know what this hack does.
 204
 205 config SMP
 206         bool "Symmetric multi-processing support (EXPERIMENTAL)"
 207         default n
 208         #SMP_BROKEN is for x86_64.
 209         depends on MODE_TT && EXPERIMENTAL && (!SMP_BROKEN || (BROKEN && SMP_BROKEN))
 210         help
 211         This option enables UML SMP support.
 212         It is NOT related to having a real SMP box. Not directly, at least.
 213
 214         UML implements virtual SMP by allowing as many processes to run
 215         simultaneously on the host as there are virtual processors configured.
 216
 217         Obviously, if the host is a uniprocessor, those processes will
 218         timeshare, but, inside UML, will appear to be running simultaneously.
 219         If the host is a multiprocessor, then UML processes may run
 220         simultaneously, depending on the host scheduler.
 221
 222         This, however, is supported only in TT mode. So, if you use the SKAS
 223         patch on your host, switching to TT mode and enabling SMP usually gives
 224         you worse performances.
 225         Also, since the support for SMP has been under-developed, there could
 226         be some bugs being exposed by enabling SMP.
 227
 228         If you don't know what to do, say N.
 229
 230 config NR_CPUS
 231         int "Maximum number of CPUs (2-32)"
 232         range 2 32
 233         depends on SMP
 234         default "32"
 235
 236 config NEST_LEVEL
 237         int "Nesting level"
 238         default "0"
 239         help
 240         This is set to the number of layers of UMLs that this UML will be run
 241         in.  Normally, this is zero, meaning that it will run directly on the
 242         host.  Setting it to one will build a UML that can run inside a UML
 243         that is running on the host.  Generally, if you intend this UML to run
 244         inside another UML, set CONFIG_NEST_LEVEL to one more than the host
 245         UML.
 246
 247         Note that if the hosting UML has its CONFIG_KERNEL_HALF_GIGS set to
 248         greater than one, then the guest UML should have its CONFIG_NEST_LEVEL
 249         set to the host's CONFIG_NEST_LEVEL + CONFIG_KERNEL_HALF_GIGS.
 250         Only change this if you are running nested UMLs.
 251
 252 config HIGHMEM
 253         bool "Highmem support (EXPERIMENTAL)"
 254         depends on !64BIT && EXPERIMENTAL
 255         default n
 256         help
 257         This was used to allow UML to run with big amounts of memory.
 258         Currently it is unstable, so if unsure say N.
 259
 260         To use big amounts of memory, it is recommended to disable TT mode (i.e.
 261         CONFIG_MODE_TT) and enable static linking (i.e. CONFIG_STATIC_LINK) -
 262         this should allow the guest to use up to 2.75G of memory.
 263
 264 config KERNEL_STACK_ORDER
 265         int "Kernel stack size order"
 266         default 2
 267         help
 268         This option determines the size of UML kernel stacks.  They will
 269         be 1 << order pages.  The default is OK unless you're running Valgrind
 270         on UML, in which case, set this to 3.
 271
 272 config UML_REAL_TIME_CLOCK
 273         bool "Real-time Clock"
 274         default y
 275         help
 276         This option makes UML time deltas match wall clock deltas.  This should
 277         normally be enabled.  The exception would be if you are debugging with
 278         UML and spend long times with UML stopped at a breakpoint.  In this
 279         case, when UML is restarted, it will call the timer enough times to make
 280         up for the time spent at the breakpoint.  This could result in a
 281         noticeable lag.  If this is a problem, then disable this option.
 282
 283 endmenu
 284
 285 source "init/Kconfig"
 286
 287 source "drivers/block/Kconfig"
 288
 289 source "arch/um/Kconfig.char"
 290
 291 source "drivers/base/Kconfig"
 292
 293 source "net/Kconfig"
 294
 295 source "arch/um/Kconfig.net"
 296
 297 source "drivers/net/Kconfig"
 298
 299 source "drivers/connector/Kconfig"
 300
 301 source "fs/Kconfig"
 302
 303 source "security/Kconfig"
 304
 305 source "crypto/Kconfig"
 306
 307 source "lib/Kconfig"
 308
 309 menu "SCSI support"
 310 depends on BROKEN
 311
 312 config SCSI
 313         tristate "SCSI support"
 314
 315 # This gives us free_dma, which scsi.c wants.
 316 config GENERIC_ISA_DMA
 317         bool
 318         depends on SCSI
 319         default y
 320
 321 source "arch/um/Kconfig.scsi"
 322
 323 endmenu
 324
 325 source "drivers/md/Kconfig"
 326
 327 if BROKEN
 328         source "drivers/mtd/Kconfig"
 329 endif
 330
 331 #This is just to shut up some Kconfig warnings, so no prompt.
 332 config INPUT
 333         bool
 334         default n
 335
 336 source "arch/um/Kconfig.debug"