bool
default y
+config ZONE_DMA
+ bool
+ default y
+
config SBUS
bool
bool
default y
+config GENERIC_BUG
+ bool
+ default y
+ depends on BUG
+
config GENERIC_HWEIGHT
bool
default y
endchoice
+config PARAVIRT
+ bool "Paravirtualization support (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ depends on !(X86_VISWS || X86_VOYAGER)
+ help
+ Paravirtualization is a way of running multiple instances of
+ Linux on the same machine, under a hypervisor. This option
+ changes the kernel so it can modify itself when it is run
+ under a hypervisor, improving performance significantly.
+ However, when run without a hypervisor the kernel is
+ theoretically slower. If in doubt, say N.
+
config ACPI_SRAT
bool
default y
choice
prompt "High Memory Support"
- default NOHIGHMEM
+ default HIGHMEM4G if !X86_NUMAQ
+ default HIGHMEM64G if X86_NUMAQ
config NOHIGHMEM
bool "off"
depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
default y
-config REGPARM
- bool "Use register arguments"
- default y
- help
- Compile the kernel with -mregparm=3. This instructs gcc to use
- a more efficient function call ABI which passes the first three
- arguments of a function call via registers, which results in denser
- and faster code.
-
- If this option is disabled, then the default ABI of passing
- arguments via the stack is used.
-
- If unsure, say Y.
-
config SECCOMP
bool "Enable seccomp to safely compute untrusted bytecode"
depends on PROC_FS
config PHYSICAL_START
hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
-
- default "0x1000000" if CRASH_DUMP
default "0x100000"
help
- This gives the physical address where the kernel is loaded. Normally
- for regular kernels this value is 0x100000 (1MB). But in the case
- of kexec on panic the fail safe kernel needs to run at a different
- address than the panic-ed kernel. This option is used to set the load
- address for kernels used to capture crash dump on being kexec'ed
- after panic. The default value for crash dump kernels is
- 0x1000000 (16MB). This can also be set based on the "X" value as
+ This gives the physical address where the kernel is loaded.
+
+ If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
+ bzImage will decompress itself to above physical address and
+ run from there. Otherwise, bzImage will run from the address where
+ it has been loaded by the boot loader and will ignore above physical
+ address.
+
+ In normal kdump cases one does not have to set/change this option
+ as now bzImage can be compiled as a completely relocatable image
+ (CONFIG_RELOCATABLE=y) and be used to load and run from a different
+ address. This option is mainly useful for the folks who don't want
+ to use a bzImage for capturing the crash dump and want to use a
+ vmlinux instead. vmlinux is not relocatable hence a kernel needs
+ to be specifically compiled to run from a specific memory area
+ (normally a reserved region) and this option comes handy.
+
+ So if you are using bzImage for capturing the crash dump, leave
+ the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
+ Otherwise if you plan to use vmlinux for capturing the crash dump
+ change this value to start of the reserved region (Typically 16MB
+ 0x1000000). In other words, it can be set based on the "X" value as
specified in the "crashkernel=YM@XM" command line boot parameter
passed to the panic-ed kernel. Typically this parameter is set as
crashkernel=64M@16M. Please take a look at
Documentation/kdump/kdump.txt for more details about crash dumps.
+ Usage of bzImage for capturing the crash dump is recommended as
+ one does not have to build two kernels. Same kernel can be used
+ as production kernel and capture kernel. Above option should have
+ gone away after relocatable bzImage support is introduced. But it
+ is present because there are users out there who continue to use
+ vmlinux for dump capture. This option should go away down the
+ line.
+
+ Don't change this unless you know what you are doing.
+
+config RELOCATABLE
+ bool "Build a relocatable kernel(EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ This build a kernel image that retains relocation information
+ so it can be loaded someplace besides the default 1MB.
+ The relocations tend to the kernel binary about 10% larger,
+ but are discarded at runtime.
+
+ One use is for the kexec on panic case where the recovery kernel
+ must live at a different physical address than the primary
+ kernel.
+
+config PHYSICAL_ALIGN
+ hex "Alignment value to which kernel should be aligned"
+ default "0x100000"
+ range 0x2000 0x400000
+ help
+ This value puts the alignment restrictions on physical address
+ where kernel is loaded and run from. Kernel is compiled for an
+ address which meets above alignment restriction.
+
+ If bootloader loads the kernel at a non-aligned address and
+ CONFIG_RELOCATABLE is set, kernel will move itself to nearest
+ address aligned to above value and run from there.
+
+ If bootloader loads the kernel at a non-aligned address and
+ CONFIG_RELOCATABLE is not set, kernel will ignore the run time
+ load address and decompress itself to the address it has been
+ compiled for and run from there. The address for which kernel is
+ compiled already meets above alignment restrictions. Hence the
+ end result is that kernel runs from a physical address meeting
+ above alignment restrictions.
+
Don't change this unless you know what you are doing.
config HOTPLUG_CPU
git.samba.org / sfrench / cifs-2.6.git / blobdiff