LXR linux/arch/um/Kconfig.i386

   1menu "Host processor type and features"
   2
   3source "arch/i386/Kconfig.cpu"
   4
   5endmenu
   6
   7config UML_X86
   8        bool
   9        default y
  10
  11config 64BIT
  12        bool
  13        default n
  14
  15config SEMAPHORE_SLEEPERS
  16        bool
  17        default y
  18
  19choice
  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
  39config HOST_VMSPLIT_3G
  40        bool "Default split (3G/1G user/kernel host split)"
  41config HOST_VMSPLIT_3G_OPT
  42        bool "3G/1G user/kernel host split (for full 1G low memory)"
  43config HOST_VMSPLIT_2G
  44        bool "2G/2G user/kernel host split"
  45config HOST_VMSPLIT_1G
  46        bool "1G/3G user/kernel host split"
  47endchoice
  48
  49config 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
  56config 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
  68config STUB_CODE
  69        hex
  70        default 0xbfffe000 if !HOST_VMSPLIT_2G
  71        default 0x7fffe000 if HOST_VMSPLIT_2G
  72
  73config STUB_DATA
  74        hex
  75        default 0xbffff000 if !HOST_VMSPLIT_2G
  76        default 0x7ffff000 if HOST_VMSPLIT_2G
  77
  78config STUB_START
  79        hex
  80        default STUB_CODE
  81
  82config ARCH_HAS_SC_SIGNALS
  83        bool
  84        default y
  85
  86config ARCH_REUSE_HOST_VSYSCALL_AREA
  87        bool
  88        default y
  89
  90config GENERIC_HWEIGHT
  91        bool
  92        default y
  93
  94