#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.txt.
#
# Note: ISA is disabled and will hopefully never be enabled.
# If you managed to buy an ISA x86-64 box you'll have to fix all the
# ISA drivers you need yourself.
#
mainmenu "Linux Kernel Configuration"
config X86_64
bool
default y
help
Port to the x86-64 architecture. x86-64 is a 64-bit extension to the
classical 32-bit x86 architecture. For details see
<http://www.x86-64.org/>.
config 64BIT
def_bool y
config X86
bool
default y
config GENERIC_TIME
bool
default y
config GENERIC_TIME_VSYSCALL
bool
default y
config GENERIC_CMOS_UPDATE
bool
default y
config CLOCKSOURCE_WATCHDOG
bool
default y
config GENERIC_CLOCKEVENTS
bool
default y
config GENERIC_CLOCKEVENTS_BROADCAST
bool
default y
config ZONE_DMA32
bool
default y
config LOCKDEP_SUPPORT
bool
default y
config STACKTRACE_SUPPORT
bool
default y
config SEMAPHORE_SLEEPERS
bool
default y
config MMU
bool
default y
config ZONE_DMA
bool
default y
config ISA
bool
config SBUS
bool
config RWSEM_GENERIC_SPINLOCK
bool
default y
config RWSEM_XCHGADD_ALGORITHM
bool
config GENERIC_HWEIGHT
bool
default y
config GENERIC_CALIBRATE_DELAY
bool
default y
config X86_CMPXCHG
bool
default y
config EARLY_PRINTK
bool
default y
config GENERIC_ISA_DMA
bool
default y
config GENERIC_IOMAP
bool
default y
config ARCH_MAY_HAVE_PC_FDC
bool
default y
config ARCH_POPULATES_NODE_MAP
def_bool y
config DMI
bool
default y
config AUDIT_ARCH
bool
default y
config GENERIC_BUG
bool
default y
depends on BUG
config ARCH_HAS_ILOG2_U32
bool
default n
config ARCH_HAS_ILOG2_U64
bool
default n
source "init/Kconfig"
menu "Processor type and features"
source "kernel/time/Kconfig"
choice
prompt "Subarchitecture Type"
default X86_PC
config X86_PC
bool "PC-compatible"
help
Choose this option if your computer is a standard PC or compatible.
config X86_VSMP
bool "Support for ScaleMP vSMP"
depends on PCI
help
Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
supposed to run on these EM64T-based machines. Only choose this option
if you have one of these machines.
endchoice
choice
prompt "Processor family"
default GENERIC_CPU
config MK8
bool "AMD-Opteron/Athlon64"
help
Optimize for AMD Opteron/Athlon64/Hammer/K8 CPUs.
config MPSC
bool "Intel P4 / older Netburst based Xeon"
help
Optimize for Intel Pentium 4 and older Nocona/Dempsey Xeon CPUs
with Intel Extended Memory 64 Technology(EM64T). For details see
<http://www.intel.com/technology/64bitextensions/>.
Note that the latest Xeons (Xeon 51xx and 53xx) are not based on the
Netburst core and shouldn't use this option. You can distinguish them
using the cpu family field
in /proc/cpuinfo. Family 15 is an older Xeon, Family 6 a newer one
(this rule only applies to systems that support EM64T)
config MCORE2
bool "Intel Core2 / newer Xeon"
help
Optimize for Intel Core2 and newer Xeons (51xx)
You can distinguish the newer Xeons from the older ones using
the cpu family field in /proc/cpuinfo. 15 is an older Xeon
(use CONFIG_MPSC then), 6 is a newer one. This rule only
applies to CPUs that support EM64T.
config GENERIC_CPU
bool "Generic-x86-64"
help
Generic x86-64 CPU.
Run equally well on all x86-64 CPUs.
endchoice
#
# Define implied options from the CPU selection here
#
config X86_L1_CACHE_BYTES
int
default "128" if GENERIC_CPU || MPSC
default "64" if MK8 || MCORE2
config X86_L1_CACHE_SHIFT
int
default "7" if GENERIC_CPU || MPSC
default "6" if MK8 || MCORE2
config X86_INTERNODE_CACHE_BYTES
int
default "4096" if X86_VSMP
default X86_L1_CACHE_BYTES if !X86_VSMP
config X86_TSC
bool
default y
config X86_GOOD_APIC
bool
default y
config MICROCODE
tristate "/dev/cpu/microcode - Intel CPU microcode support"
select FW_LOADER
---help---
If you say Y here the 'File systems' section, you will be
able to update the microcode on Intel processors. You will
obviously need the actual microcode binary data itself which is
not shipped with the Linux kernel.
For latest news and information on obtaining all the required
ingredients for this driver, check:
<http://www.urbanmyth.org/microcode/>.
To compile this driver as a module, choose M here: the
module will be called microcode.
If you use modprobe or kmod you may also want to add the line
'alias char-major-10-184 microcode' to your /etc/modules.conf file.
config MICROCODE_OLD_INTERFACE
bool
depends on MICROCODE
default y
config X86_MSR
tristate "/dev/cpu/*/msr - Model-specific register support"
help
This device gives privileged processes access to the x86
Model-Specific Registers (MSRs). It is a character device with
major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
MSR accesses are directed to a specific CPU on multi-processor
systems.
config X86_CPUID
tristate "/dev/cpu/*/cpuid - CPU information support"
help
This device gives processes access to the x86 CPUID instruction to
be executed on a specific processor. It is a character device
with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
/dev/cpu/31/cpuid.
config X86_HT
bool
depends on SMP && !MK8
default y
config MATH_EMULATION
bool
config MCA
bool
config EISA
bool
config X86_IO_APIC
bool
default y
config X86_LOCAL_APIC
bool
default y
config MTRR
bool "MTRR (Memory Type Range Register) support"
---help---
On Intel P6 family processors (Pentium Pro, Pentium II and later)
the Memory Type Range Registers (MTRRs) may be used to control
processor access to memory ranges. This is most useful if you have
a video (VGA) card on a PCI or AGP bus. Enabling write-combining
allows bus write transfers to be combined into a larger transfer
before bursting over the PCI/AGP bus. This can increase performance
of image write operations 2.5 times or more. Saying Y here creates a
/proc/mtrr file which may be used to manipulate your processor's
MTRRs. Typically the X server should use this.
This code has a reasonably generic interface so that similar
control registers on other processors can be easily supported
as well.
Saying Y here also fixes a problem with buggy SMP BIOSes which only
set the MTRRs for the boot CPU and not for the secondary CPUs. This
can lead to all sorts of problems, so it's good to say Y here.
Just say Y here, all x86-64 machines support MTRRs.
See <file:Documentation/mtrr.txt> for more information.
config SMP
bool "Symmetric multi-processing support"
---help---
This enables support for systems with more than one CPU. If you have
a system with only one CPU, like most personal computers, say N. If
you have a system with more than one CPU, say Y.
If you say N here, the kernel will run on single and multiprocessor
machines, but will use only one CPU of a multiprocessor machine. If
you say Y here, the kernel will run on many, but not all,
singleprocessor machines. On a singleprocessor machine, the kernel
will run faster if you say N here.
If you don't know what to do here, say N.
config SCHED_SMT
bool "SMT (Hyperthreading) scheduler support"
depends on SMP
default n
help
SMT scheduler support improves the CPU scheduler's decision making
when dealing with Intel Pentium 4 chips with HyperThreading at a
cost of slightly increased overhead in some places. If unsure say
N here.
config SCHED_MC
bool "Multi-core scheduler support"
depends on SMP
default y
help
Multi-core scheduler support improves the CPU scheduler's decision
making when dealing with multi-core CPU chips at a cost of slightly
increased overhead in some places. If unsure say N here.
source "kernel/Kconfig.preempt"
config NUMA
bool "Non Uniform Memory Access (NUMA) Support"
depends on SMP
help
Enable NUMA (Non Uniform Memory Access) support. The kernel
will try to allocate memory used by a CPU on the local memory
controller of the CPU and add some more NUMA awareness to the kernel.
This code is recommended on all multiprocessor Opteron systems.
If the system is EM64T, you should say N unless your system is EM64T
NUMA.
config K8_NUMA
bool "Old style AMD Opteron NUMA detection"
depends on NUMA && PCI
default y
help
Enable K8 NUMA node topology detection. You should say Y here if
you have a multi processor AMD K8 system. This uses an old
method to read the NUMA configuration directly from the builtin
Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
instead, which also takes priority if both are compiled in.
config NODES_SHIFT
int
default "6"
depends on NEED_MULTIPLE_NODES
# Dummy CONFIG option to select ACPI_NUMA from drivers/acpi/Kconfig.
config X86_64_ACPI_NUMA
bool "ACPI NUMA detection"
depends on NUMA
select ACPI
select PCI
select ACPI_NUMA
default y
help
Enable ACPI SRAT based node topology detection.
config NUMA_EMU
bool "NUMA emulation"
depends on NUMA
help
Enable NUMA emulation. A flat machine will be split
into virtual nodes when booted with "numa=fake=N", where N is the
number of nodes. This is only useful for debugging.
config ARCH_DISCONTIGMEM_ENABLE
bool
depends on NUMA
default y
config ARCH_DISCONTIGMEM_DEFAULT
def_bool y
depends on NUMA
config ARCH_SPARSEMEM_ENABLE
def_bool y
depends on (NUMA || EXPERIMENTAL)
select SPARSEMEM_VMEMMAP_ENABLE
config ARCH_MEMORY_PROBE
def_bool y
depends on MEMORY_HOTPLUG
config ARCH_FLATMEM_ENABLE
def_bool y
depends on !NUMA
source "mm/Kconfig"
config MEMORY_HOTPLUG_RESERVE
def_bool y
depends on (MEMORY_HOTPLUG && DISCONTIGMEM)
config HAVE_ARCH_EARLY_PFN_TO_NID
def_bool y
depends on NUMA
config OUT_OF_LINE_PFN_TO_PAGE
def_bool y
depends on DISCONTIGMEM
config NR_CPUS
int "Maximum number of CPUs (2-255)"
range 2 255
depends on SMP
default "8"
help
This allows you to specify the maximum number of CPUs which this
kernel will support. Current maximum is 255 CPUs due to
APIC addressing limits. Less depending on the hardware.
This is purely to save memory - each supported CPU requires
memory in the static kernel configuration.
config PHYSICAL_ALIGN
hex
default "0x200000"
config HOTPLUG_CPU
bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
depends on SMP && HOTPLUG && EXPERIMENTAL
help
Say Y here to experiment with turning CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu/cpu#.
This is also required for suspend/hibernation on SMP systems.
Say N if you want to disable CPU hotplug and don't need to
suspend.
config ARCH_ENABLE_MEMORY_HOTPLUG
def_bool y
config HPET_TIMER
bool
default y
help
Use the IA-PC HPET (High Precision Event Timer) to manage
time in preference to the PIT and RTC, if a HPET is
present. The HPET provides a stable time base on SMP
systems, unlike the TSC, but it is more expensive to access,
as it is off-chip. You can find the HPET spec at
<http://www.intel.com/hardwaredesign/hpetspec.htm>.
config HPET_EMULATE_RTC
bool "Provide RTC interrupt"
depends on HPET_TIMER && RTC=y
# Mark as embedded because too many people got it wrong.
# The code disables itself when not needed.
config IOMMU
bool "IOMMU support" if EMBEDDED
default y
select SWIOTLB
select AGP
depends on PCI
help
Support for full DMA access of devices with 32bit memory access only
on systems with more than 3GB. This is usually needed for USB,
sound, many IDE/SATA chipsets and some other devices.
Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
based hardware IOMMU and a software bounce buffer based IOMMU used
on Intel systems and as fallback.
The code is only active when needed (enough memory and limited
device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
too.
config CALGARY_IOMMU
bool "IBM Calgary IOMMU support"
select SWIOTLB
depends on PCI && EXPERIMENTAL
help
Support for hardware IOMMUs in IBM's xSeries x366 and x460
systems. Needed to run systems with more than 3GB of memory
properly with 32-bit PCI devices that do not support DAC
(Double Address Cycle). Calgary also supports bus level
isolation, where all DMAs pass through the IOMMU. This
prevents them from going anywhere except their intended
destination. This catches hard-to-find kernel bugs and
mis-behaving drivers and devices that do not use the DMA-API
properly to set up their DMA buffers. The IOMMU can be
turned off at boot time with the iommu=off parameter.
Normally the kernel will make the right choice by itself.
If unsure, say Y.
config CALGARY_IOMMU_ENABLED_BY_DEFAULT
bool "Should Calgary be enabled by default?"
default y
depends on CALGARY_IOMMU
help
Should Calgary be enabled by default? if you choose 'y', Calgary
will be used (if it exists). If you choose 'n', Calgary will not be
used even if it exists. If you choose 'n' and would like to use
Calgary anyway, pass 'iommu=calgary' on the kernel command line.
If unsure, say Y.
# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
bool
help
Support for software bounce buffers used on x86-64 systems
which don't have a hardware IOMMU (e.g. the current generation
of Intel's x86-64 CPUs). Using this PCI devices which can only
access 32-bits of memory can be used on systems with more than
3 GB of memory. If unsure, say Y.
config X86_MCE
bool "Machine check support" if EMBEDDED
default y
help
Include a machine check error handler to report hardware errors.
This version will require the mcelog utility to decode some
machine check error logs. See
ftp://ftp.x86-64.org/pub/linux/tools/mcelog
config X86_MCE_INTEL
bool "Intel MCE features"
depends on X86_MCE && X86_LOCAL_APIC
default y
help
Additional support for intel specific MCE features such as
the thermal monitor.
config X86_MCE_AMD
bool "AMD MCE features"
depends on X86_MCE && X86_LOCAL_APIC
default y
help
Additional support for AMD specific MCE features such as
the DRAM Error Threshold.
config KEXEC
bool "kexec system call"
help
kexec is a system call that implements the ability to shutdown your
current kernel, and to start another kernel. It is like a reboot
but it is independent of the system firmware. And like a reboot
you can start any kernel with it, not just Linux.
The name comes from the similarity to the exec system call.
It is an ongoing process to be certain the hardware in a machine
is properly shutdown, so do not be surprised if this code does not
initially work for you. It may help to enable device hotplugging
support. As of this writing the exact hardware interface is
strongly in flux, so no good recommendation can be made.
config CRASH_DUMP
bool "kernel crash dumps (EXPERIMENTAL)"
depends on EXPERIMENTAL
help
Generate crash dump after being started by kexec.
This should be normally only set in special crash dump kernels
which are loaded in the main kernel with kexec-tools into
a specially reserved region and then later executed after
a crash by kdump/kexec. The crash dump kernel must be compiled
to a memory address not used by the main kernel or BIOS using
PHYSICAL_START, or it must be built as a relocatable image
(CONFIG_RELOCATABLE=y).
For more details see Documentation/kdump/kdump.txt
config RELOCATABLE
bool "Build a relocatable kernel (EXPERIMENTAL)"
depends on EXPERIMENTAL
help
Builds a relocatable kernel. This enables loading and running
a kernel binary from a different physical address than it has
been compiled for.
One use is for the kexec on panic case where the recovery kernel
must live at a different physical address than the primary
kernel.
Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
it has been loaded at and the compile time physical address
(CONFIG_PHYSICAL_START) is ignored.
config PHYSICAL_START
hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
default "0x200000"
help
This gives the physical address where the kernel is loaded. It
should be aligned to 2MB boundary.
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.
So if you are using bzImage for capturing the crash dump, leave
the value here unchanged to 0x200000 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 advantageous as
one does not have to build two kernels. Same kernel can be used
as production kernel and capture kernel.
Don't change this unless you know what you are doing.
config SECCOMP
bool "Enable seccomp to safely compute untrusted bytecode"
depends on PROC_FS
default y
help
This kernel feature is useful for number crunching applications
that may need to compute untrusted bytecode during their
execution. By using pipes or other transports made available to
the process as file descriptors supporting the read/write
syscalls, it's possible to isolate those applications in
their own address space using seccomp. Once seccomp is
enabled via /proc/<pid>/seccomp, it cannot be disabled
and the task is only allowed to execute a few safe syscalls
defined by each seccomp mode.
If unsure, say Y. Only embedded should say N here.
config CC_STACKPROTECTOR
bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
depends on EXPERIMENTAL
help
This option turns on the -fstack-protector GCC feature. This
feature puts, at the beginning of critical functions, a canary
value on the stack just before the return address, and validates
the value just before actually returning. Stack based buffer
overflows (that need to overwrite this return address) now also
overwrite the canary, which gets detected and the attack is then
neutralized via a kernel panic.
This feature requires gcc version 4.2 or above, or a distribution
gcc with the feature backported. Older versions are automatically
detected and for those versions, this configuration option is ignored.
config CC_STACKPROTECTOR_ALL
bool "Use stack-protector for all functions"
depends on CC_STACKPROTECTOR
help
Normally, GCC only inserts the canary value protection for
functions that use large-ish on-stack buffers. By enabling
this option, GCC will be asked to do this for ALL functions.
source kernel/Kconfig.hz
config K8_NB
def_bool y
depends on AGP_AMD64 || IOMMU || (PCI && NUMA)
endmenu
#
# Use the generic interrupt handling code in kernel/irq/:
#
config GENERIC_HARDIRQS
bool
default y
config GENERIC_IRQ_PROBE
bool
default y
# we have no ISA slots, but we do have ISA-style DMA.
config ISA_DMA_API
bool
default y
config GENERIC_PENDING_IRQ
bool
depends on GENERIC_HARDIRQS && SMP
default y
menu "Power management options"
source kernel/power/Kconfig
source "drivers/acpi/Kconfig"
source "arch/x86/kernel/cpufreq/Kconfig"
endmenu
menu "Bus options (PCI etc.)"
config PCI
bool "PCI support"
select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
bool
depends on PCI
default y
config PCI_MMCONFIG
bool "Support mmconfig PCI config space access"
depends on PCI && ACPI
config PCI_DOMAINS
bool
depends on PCI
default y
source "drivers/pci/pcie/Kconfig"
source "drivers/pci/Kconfig"
source "drivers/pcmcia/Kconfig"
source "drivers/pci/hotplug/Kconfig"
endmenu
menu "Executable file formats / Emulations"
source "fs/Kconfig.binfmt"
config IA32_EMULATION
bool "IA32 Emulation"
help
Include code to run 32-bit programs under a 64-bit kernel. You should likely
turn this on, unless you're 100% sure that you don't have any 32-bit programs
left.
config IA32_AOUT
tristate "IA32 a.out support"
depends on IA32_EMULATION
help
Support old a.out binaries in the 32bit emulation.
config COMPAT
bool
depends on IA32_EMULATION
default y
config COMPAT_FOR_U64_ALIGNMENT
def_bool COMPAT
config SYSVIPC_COMPAT
bool
depends on COMPAT && SYSVIPC
default y
endmenu
source "net/Kconfig"
source drivers/Kconfig
source "drivers/firmware/Kconfig"
source fs/Kconfig
menu "Instrumentation Support"
source "arch/x86/oprofile/Kconfig"
config KPROBES
bool "Kprobes"
depends on KALLSYMS && MODULES
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
a probepoint and specifies the callback. Kprobes is useful
for kernel debugging, non-intrusive instrumentation and testing.
If in doubt, say "N".
endmenu
source "arch/x86_64/Kconfig.debug"
source "security/Kconfig"
source "crypto/Kconfig"
source "lib/Kconfig"
