arch/um/Kconfig.i386

   1 menu "Host processor type and features"
   2
   3 source "arch/i386/Kconfig.cpu"
   4
   5 endmenu
   6
   7 config UML_X86
   8         bool
   9         default y
  10
  11 config 64BIT
  12         bool
  13         default n
  14
  15 config SEMAPHORE_SLEEPERS
  16         bool
  17         default y
  18
  19 choice
  20         prompt "Host memory split"
  21         default HOST_VMSPLIT_3G
  22         help
  23         This is needed when the host kernel on which you run has a non-default
  24         (like 2G/2G) memory split, instead of the customary 3G/1G. If you did
  25         not recompile your own kernel but use the default distro's one, you can
  26         safely accept the "Default split" option.
  27
  28         It can be enabled on recent (>=2.6.16-rc2) vanilla kernels via
  29         CONFIG_VM_SPLIT_*, or on previous kernels with special patches (-ck
  30         patchset by Con Kolivas, or other ones) - option names match closely the
  31         host CONFIG_VM_SPLIT_* ones.
  32
  33         A lower setting (where 1G/3G is lowest and 3G/1G is higher) will
  34         tolerate even more "normal" host kernels, but an higher setting will be
  35         stricter.
  36
  37         So, if you do not know what to do here, say 'Default split'.
  38
  39 config HOST_VMSPLIT_3G
  40         bool "Default split (3G/1G user/kernel host split)"
  41 config HOST_VMSPLIT_3G_OPT
  42         bool "3G/1G user/kernel host split (for full 1G low memory)"
  43 config HOST_VMSPLIT_2G
  44         bool "2G/2G user/kernel host split"
  45 config HOST_VMSPLIT_1G
  46         bool "1G/3G user/kernel host split"
  47 endchoice
  48
  49 config TOP_ADDR
  50         hex
  51         default 0xB0000000 if HOST_VMSPLIT_3G_OPT
  52         default 0x78000000 if HOST_VMSPLIT_2G
  53         default 0x40000000 if HOST_VMSPLIT_1G
  54         default 0xC0000000
  55
  56 config 3_LEVEL_PGTABLES
  57         bool "Three-level pagetables (EXPERIMENTAL)"
  58         default n
  59         depends on EXPERIMENTAL
  60         help
  61         Three-level pagetables will let UML have more than 4G of physical
  62         memory.  All the memory that can't be mapped directly will be treated
  63         as high memory.
  64
  65         However, this it experimental on 32-bit architectures, so if unsure say
  66         N (on x86-64 it's automatically enabled, instead, as it's safe there).
  67
  68 config STUB_CODE
  69         hex
  70         default 0xbfffe000 if !HOST_VMSPLIT_2G
  71         default 0x7fffe000 if HOST_VMSPLIT_2G
  72
  73 config STUB_DATA
  74         hex
  75         default 0xbffff000 if !HOST_VMSPLIT_2G
  76         default 0x7ffff000 if HOST_VMSPLIT_2G
  77
  78 config STUB_START
  79         hex
  80         default STUB_CODE
  81
  82 config ARCH_HAS_SC_SIGNALS
  83         bool
  84         default y
  85
  86 config ARCH_REUSE_HOST_VSYSCALL_AREA
  87         bool
  88         default y
  89
  90 config GENERIC_HWEIGHT
  91         bool
  92         default y
  93