arch/um/Kconfig.um

   1 config STATIC_LINK
   2         bool "Force a static link"
   3         default n
   4         help
   5           This option gives you the ability to force a static link of UML.
   6           Normally, UML is linked as a shared binary.  This is inconvenient for
   7           use in a chroot jail.  So, if you intend to run UML inside a chroot,
   8           you probably want to say Y here.
   9           Additionally, this option enables using higher memory spaces (up to
  10           2.75G) for UML.
  11
  12 source "mm/Kconfig"
  13
  14 config LD_SCRIPT_STATIC
  15         bool
  16         default y
  17         depends on STATIC_LINK
  18
  19 config LD_SCRIPT_DYN
  20         bool
  21         default y
  22         depends on !LD_SCRIPT_STATIC
  23
  24 source "fs/Kconfig.binfmt"
  25
  26 config HOSTFS
  27         tristate "Host filesystem"
  28         help
  29           While the User-Mode Linux port uses its own root file system for
  30           booting and normal file access, this module lets the UML user
  31           access files stored on the host.  It does not require any
  32           network connection between the Host and UML.  An example use of
  33           this might be:
  34
  35           mount none /tmp/fromhost -t hostfs -o /tmp/umlshare
  36
  37           where /tmp/fromhost is an empty directory inside UML and
  38           /tmp/umlshare is a directory on the host with files the UML user
  39           wishes to access.
  40
  41           For more information, see
  42           <http://user-mode-linux.sourceforge.net/hostfs.html>.
  43
  44           If you'd like to be able to work with files stored on the host,
  45           say Y or M here; otherwise say N.
  46
  47 config HPPFS
  48         tristate "HoneyPot ProcFS"
  49         depends on PROC_FS
  50         help
  51           hppfs (HoneyPot ProcFS) is a filesystem which allows UML /proc
  52           entries to be overridden, removed, or fabricated from the host.
  53           Its purpose is to allow a UML to appear to be a physical machine
  54           by removing or changing anything in /proc which gives away the
  55           identity of a UML.
  56
  57           See <http://user-mode-linux.sf.net/old/hppfs.html> for more information.
  58
  59           You only need this if you are setting up a UML honeypot.  Otherwise,
  60           it is safe to say 'N' here.
  61
  62 config MCONSOLE
  63         bool "Management console"
  64         default y
  65         help
  66           The user mode linux management console is a low-level interface to
  67           the kernel, somewhat like the i386 SysRq interface.  Since there is
  68           a full-blown operating system running under every user mode linux
  69           instance, there is much greater flexibility possible than with the
  70           SysRq mechanism.
  71
  72           If you answer 'Y' to this option, to use this feature, you need the
  73           mconsole client (called uml_mconsole) which is present in CVS in
  74           2.4.5-9um and later (path /tools/mconsole), and is also in the
  75           distribution RPM package in 2.4.6 and later.
  76
  77           It is safe to say 'Y' here.
  78
  79 config MAGIC_SYSRQ
  80         bool "Magic SysRq key"
  81         depends on MCONSOLE
  82         help
  83           If you say Y here, you will have some control over the system even
  84           if the system crashes for example during kernel debugging (e.g., you
  85           will be able to flush the buffer cache to disk, reboot the system
  86           immediately or dump some status information). A key for each of the
  87           possible requests is provided.
  88
  89           This is the feature normally accomplished by pressing a key
  90           while holding SysRq (Alt+PrintScreen).
  91
  92           On UML, this is accomplished by sending a "sysrq" command with
  93           mconsole, followed by the letter for the requested command.
  94
  95           The keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
  96           unless you really know what this hack does.
  97
  98 config SMP
  99         bool "Symmetric multi-processing support"
 100         default n
 101         depends on BROKEN
 102         help
 103           This option enables UML SMP support.
 104           It is NOT related to having a real SMP box. Not directly, at least.
 105
 106           UML implements virtual SMP by allowing as many processes to run
 107           simultaneously on the host as there are virtual processors configured.
 108
 109           Obviously, if the host is a uniprocessor, those processes will
 110           timeshare, but, inside UML, will appear to be running simultaneously.
 111           If the host is a multiprocessor, then UML processes may run
 112           simultaneously, depending on the host scheduler.
 113
 114           This, however, is supported only in TT mode. So, if you use the SKAS
 115           patch on your host, switching to TT mode and enabling SMP usually
 116           gives you worse performances.
 117           Also, since the support for SMP has been under-developed, there could
 118           be some bugs being exposed by enabling SMP.
 119
 120           If you don't know what to do, say N.
 121
 122 config NR_CPUS
 123         int "Maximum number of CPUs (2-32)"
 124         range 2 32
 125         depends on SMP
 126         default "32"
 127
 128 config HIGHMEM
 129         bool "Highmem support"
 130         depends on !64BIT && BROKEN
 131         default n
 132         help
 133           This was used to allow UML to run with big amounts of memory.
 134           Currently it is unstable, so if unsure say N.
 135
 136           To use big amounts of memory, it is recommended enable static
 137           linking (i.e. CONFIG_STATIC_LINK) - this should allow the
 138           guest to use up to 2.75G of memory.
 139
 140 config KERNEL_STACK_ORDER
 141         int "Kernel stack size order"
 142         default 1 if 64BIT
 143         range 1 10 if 64BIT
 144         default 0 if !64BIT
 145         help
 146           This option determines the size of UML kernel stacks.  They will
 147           be 1 << order pages.  The default is OK unless you're running Valgrind
 148           on UML, in which case, set this to 3.
 149
 150 config MMAPPER
 151         tristate "iomem emulation driver"
 152         help
 153           This driver allows a host file to be used as emulated IO memory inside
 154           UML.
 155
 156 config NO_DMA
 157         def_bool y