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-rw-r--r--arch/i386/Kconfig56
1 files changed, 47 insertions, 9 deletions
diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index cbde675bc95c..0afec8566e7b 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -47,15 +47,6 @@ config DMI
source "init/Kconfig"
-config DOUBLEFAULT
- default y
- bool "Enable doublefault exception handler" if EMBEDDED
- help
- This option allows trapping of rare doublefault exceptions that
- would otherwise cause a system to silently reboot. Disabling this
- option saves about 4k and might cause you much additional grey
- hair.
-
menu "Processor type and features"
choice
@@ -451,12 +442,50 @@ config HIGHMEM4G
config HIGHMEM64G
bool "64GB"
+ depends on X86_CMPXCHG64
help
Select this if you have a 32-bit processor and more than 4
gigabytes of physical RAM.
endchoice
+choice
+ depends on EXPERIMENTAL && !X86_PAE
+ prompt "Memory split"
+ default VMSPLIT_3G
+ help
+ Select the desired split between kernel and user memory.
+
+ If the address range available to the kernel is less than the
+ physical memory installed, the remaining memory will be available
+ as "high memory". Accessing high memory is a little more costly
+ than low memory, as it needs to be mapped into the kernel first.
+ Note that increasing the kernel address space limits the range
+ available to user programs, making the address space there
+ tighter. Selecting anything other than the default 3G/1G split
+ will also likely make your kernel incompatible with binary-only
+ kernel modules.
+
+ If you are not absolutely sure what you are doing, leave this
+ option alone!
+
+ config VMSPLIT_3G
+ bool "3G/1G user/kernel split"
+ config VMSPLIT_3G_OPT
+ bool "3G/1G user/kernel split (for full 1G low memory)"
+ config VMSPLIT_2G
+ bool "2G/2G user/kernel split"
+ config VMSPLIT_1G
+ bool "1G/3G user/kernel split"
+endchoice
+
+config PAGE_OFFSET
+ hex
+ default 0xB0000000 if VMSPLIT_3G_OPT
+ default 0x78000000 if VMSPLIT_2G
+ default 0x40000000 if VMSPLIT_1G
+ default 0xC0000000
+
config HIGHMEM
bool
depends on HIGHMEM64G || HIGHMEM4G
@@ -711,6 +740,15 @@ config HOTPLUG_CPU
Say N.
+config DOUBLEFAULT
+ default y
+ bool "Enable doublefault exception handler" if EMBEDDED
+ help
+ This option allows trapping of rare doublefault exceptions that
+ would otherwise cause a system to silently reboot. Disabling this
+ option saves about 4k and might cause you much additional grey
+ hair.
+
endmenu