bridge: allow changing hardware address to any valid address

[safe/jmp/linux-2.6] / Documentation / kernel-parameters.txt

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 06e362b..12533a9 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1,4 +1,4 @@
-February 2003             Kernel Parameters                     v2.5.59
+                          Kernel Parameters

                           ~~~~~~~~~~~~~~~~~
 
 The following is a consolidated list of the kernel parameters as implemented
                           ~~~~~~~~~~~~~~~~~
 
 The following is a consolidated list of the kernel parameters as implemented


@@ -17,9 +17,17 @@ are specified on the kernel command line with the module name plus
 
        usbcore.blinkenlights=1
 
 
        usbcore.blinkenlights=1
 

-The text in square brackets at the beginning of the description states the
-restrictions on the kernel for the said kernel parameter to be valid. The
-restrictions referred to are that the relevant option is valid if:
+This document may not be entirely up to date and comprehensive. The command
+"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
+module. Loadable modules, after being loaded into the running kernel, also
+reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
+parameters may be changed at runtime by the command
+"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
+
+The parameters listed below are only valid if certain kernel build options were
+enabled and if respective hardware is present. The text in square brackets at
+the beginning of each description states the restrictions within which a
+parameter is applicable:

 
        ACPI    ACPI support is enabled.
        ALSA    ALSA sound support is enabled.
 
        ACPI    ACPI support is enabled.
        ALSA    ALSA sound support is enabled.


@@ -27,7 +35,6 @@ restrictions referred to are that the relevant option is valid if:
        APM     Advanced Power Management support is enabled.
        AX25    Appropriate AX.25 support is enabled.
        CD      Appropriate CD support is enabled.
        APM     Advanced Power Management support is enabled.
        AX25    Appropriate AX.25 support is enabled.
        CD      Appropriate CD support is enabled.

-       DEVFS   devfs support is enabled.

        DRM     Direct Rendering Management support is enabled.
        EDD     BIOS Enhanced Disk Drive Services (EDD) is enabled
        EFI     EFI Partitioning (GPT) is enabled
        DRM     Direct Rendering Management support is enabled.
        EDD     BIOS Enhanced Disk Drive Services (EDD) is enabled
        EFI     EFI Partitioning (GPT) is enabled


@@ -41,6 +48,7 @@ restrictions referred to are that the relevant option is valid if:
        ISAPNP  ISA PnP code is enabled.
        ISDN    Appropriate ISDN support is enabled.
        JOY     Appropriate joystick support is enabled.
        ISAPNP  ISA PnP code is enabled.
        ISDN    Appropriate ISDN support is enabled.
        JOY     Appropriate joystick support is enabled.

+       LIBATA  Libata driver is enabled

        LP      Printer support is enabled.
        LOOP    Loopback device support is enabled.
        M68k    M68k architecture is enabled.
        LP      Printer support is enabled.
        LOOP    Loopback device support is enabled.
        M68k    M68k architecture is enabled.


@@ -49,9 +57,11 @@ restrictions referred to are that the relevant option is valid if:
        MCA     MCA bus support is enabled.
        MDA     MDA console support is enabled.
        MOUSE   Appropriate mouse support is enabled.
        MCA     MCA bus support is enabled.
        MDA     MDA console support is enabled.
        MOUSE   Appropriate mouse support is enabled.

+       MSI     Message Signaled Interrupts (PCI).

        MTD     MTD support is enabled.
        NET     Appropriate network support is enabled.
        NUMA    NUMA support is enabled.
        MTD     MTD support is enabled.
        NET     Appropriate network support is enabled.
        NUMA    NUMA support is enabled.

+       GENERIC_TIME The generic timeofday code is enabled.

        NFS     Appropriate NFS support is enabled.
        OSS     OSS sound support is enabled.
        PARIDE  The ParIDE subsystem is enabled.
        NFS     Appropriate NFS support is enabled.
        OSS     OSS sound support is enabled.
        PARIDE  The ParIDE subsystem is enabled.


@@ -69,6 +79,7 @@ restrictions referred to are that the relevant option is valid if:
                        Documentation/scsi/.
        SELINUX SELinux support is enabled.
        SERIAL  Serial support is enabled.
                        Documentation/scsi/.
        SELINUX SELinux support is enabled.
        SERIAL  Serial support is enabled.

+       SH      SuperH architecture is enabled.

        SMP     The kernel is an SMP kernel.
        SPARC   Sparc architecture is enabled.
        SWSUSP  Software suspend is enabled.
        SMP     The kernel is an SMP kernel.
        SPARC   Sparc architecture is enabled.
        SWSUSP  Software suspend is enabled.


@@ -95,17 +106,28 @@ loader, and have no meaning to the kernel directly.
 Do not modify the syntax of boot loader parameters without extreme
 need or coordination with <Documentation/i386/boot.txt>.
 
 Do not modify the syntax of boot loader parameters without extreme
 need or coordination with <Documentation/i386/boot.txt>.
 

+There are also arch-specific kernel-parameters not documented here.
+See for example <Documentation/x86_64/boot-options.txt>.
+

 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
 a trailing = on the name of any parameter states that that parameter will
 be entered as an environment variable, whereas its absence indicates that
 it will appear as a kernel argument readable via /proc/cmdline by programs
 running once the system is up.
 
 Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
 a trailing = on the name of any parameter states that that parameter will
 be entered as an environment variable, whereas its absence indicates that
 it will appear as a kernel argument readable via /proc/cmdline by programs
 running once the system is up.
 

+The number of kernel parameters is not limited, but the length of the
+complete command line (parameters including spaces etc.) is limited to
+a fixed number of characters. This limit depends on the architecture
+and is between 256 and 4096 characters. It is defined in the file
+./include/asm/setup.h as COMMAND_LINE_SIZE.
+
+

        53c7xx=         [HW,SCSI] Amiga SCSI controllers
                        See header of drivers/scsi/53c7xx.c.
                        See also Documentation/scsi/ncr53c7xx.txt.
 
        53c7xx=         [HW,SCSI] Amiga SCSI controllers
                        See header of drivers/scsi/53c7xx.c.
                        See also Documentation/scsi/ncr53c7xx.txt.
 

-       acpi=           [HW,ACPI] Advanced Configuration and Power Interface
+       acpi=           [HW,ACPI,X86-64,i386]
+                       Advanced Configuration and Power Interface

                        Format: { force | off | ht | strict | noirq }
                        force -- enable ACPI if default was off
                        off -- disable ACPI if default was on
                        Format: { force | off | ht | strict | noirq }
                        force -- enable ACPI if default was off
                        off -- disable ACPI if default was on


@@ -116,6 +138,12 @@ running once the system is up.
 
                        See also Documentation/pm.txt, pci=noacpi
 
 
                        See also Documentation/pm.txt, pci=noacpi
 

+       acpi_apic_instance=     [ACPI, IOAPIC]
+                       Format: <int>
+                       2: use 2nd APIC table, if available
+                       1,0: use 1st APIC table
+                       default: 0
+

        acpi_sleep=     [HW,ACPI] Sleep options
                        Format: { s3_bios, s3_mode }
                        See Documentation/power/video.txt
        acpi_sleep=     [HW,ACPI] Sleep options
                        Format: { s3_bios, s3_mode }
                        See Documentation/power/video.txt


@@ -138,6 +166,9 @@ running once the system is up.
        acpi_irq_isa=   [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
                        Format: <irq>,<irq>...
 
        acpi_irq_isa=   [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
                        Format: <irq>,<irq>...
 

+       acpi_os_name=   [HW,ACPI] Tell ACPI BIOS the name of the OS
+                       Format: To spoof as Windows 98: ="Microsoft Windows"
+

        acpi_osi=       [HW,ACPI] empty param disables _OSI
 
        acpi_serialize  [HW,ACPI] force serialization of AML methods
        acpi_osi=       [HW,ACPI] empty param disables _OSI
 
        acpi_serialize  [HW,ACPI] force serialization of AML methods


@@ -145,6 +176,10 @@ running once the system is up.
        acpi_skip_timer_override [HW,ACPI]
                        Recognize and ignore IRQ0/pin2 Interrupt Override.
                        For broken nForce2 BIOS resulting in XT-PIC timer.
        acpi_skip_timer_override [HW,ACPI]
                        Recognize and ignore IRQ0/pin2 Interrupt Override.
                        For broken nForce2 BIOS resulting in XT-PIC timer.

+       acpi_use_timer_override [HW,ACPI}
+                       Use timer override. For some broken Nvidia NF5 boards
+                       that require a timer override, but don't have
+                       HPET

 
        acpi_dbg_layer= [HW,ACPI]
                        Format: <int>
 
        acpi_dbg_layer= [HW,ACPI]
                        Format: <int>


@@ -167,6 +202,11 @@ running once the system is up.
                        override platform specific driver.
                        See also Documentation/acpi-hotkey.txt.
 
                        override platform specific driver.
                        See also Documentation/acpi-hotkey.txt.
 

+       acpi_pm_good    [IA-32,X86-64]
+                       Override the pmtimer bug detection: force the kernel
+                       to assume that this machine's pmtimer latches its value
+                       and always returns good values.
+

        enable_timer_pin_1 [i386,x86-64]
                        Enable PIN 1 of APIC timer
                        Can be useful to work around chipset bugs
        enable_timer_pin_1 [i386,x86-64]
                        Enable PIN 1 of APIC timer
                        Can be useful to work around chipset bugs


@@ -265,9 +305,6 @@ running once the system is up.
 
        autotest        [IA64]
 
 
        autotest        [IA64]
 

-       awe=            [HW,OSS] AWE32/SB32/AWE64 wave table synth
-                       Format: <io>,<memsize>,<isapnp>
-

        aztcd=          [HW,CD] Aztech CD268 CDROM driver
                        Format: <io>,0x79 (?)
 
        aztcd=          [HW,CD] Aztech CD268 CDROM driver
                        Format: <io>,0x79 (?)
 


@@ -329,12 +366,24 @@ running once the system is up.
                        Value can be changed at runtime via
                                /selinux/checkreqprot.
 
                        Value can be changed at runtime via
                                /selinux/checkreqprot.
 

-       clock=          [BUGS=IA-32,HW] gettimeofday timesource override.
-                       Forces specified timesource (if avaliable) to be used
-                       when calculating gettimeofday(). If specicified
-                       timesource is not avalible, it defaults to PIT.
+       clock=          [BUGS=IA-32, HW] gettimeofday clocksource override.
+                       [Deprecated]
+                       Forces specified clocksource (if available) to be used
+                       when calculating gettimeofday(). If specified
+                       clocksource is not available, it defaults to PIT.

                        Format: { pit | tsc | cyclone | pmtmr }
 
                        Format: { pit | tsc | cyclone | pmtmr }
 

+       code_bytes      [IA32] How many bytes of object code to print in an
+                       oops report.
+                       Range: 0 - 8192
+                       Default: 64
+
+       disable_8254_timer
+       enable_8254_timer
+                       [IA32/X86_64] Disable/Enable interrupt 0 timer routing
+                       over the 8254 in addition to over the IO-APIC. The
+                       kernel tries to set a sensible default.
+

        hpet=           [IA-32,HPET] option to disable HPET and use PIT.
                        Format: disable
 
        hpet=           [IA-32,HPET] option to disable HPET and use PIT.
                        Format: disable
 


@@ -360,12 +409,17 @@ running once the system is up.
                tty<n>  Use the virtual console device <n>.
 
                ttyS<n>[,options]
                tty<n>  Use the virtual console device <n>.
 
                ttyS<n>[,options]

+               ttyUSB0[,options]

                        Use the specified serial port.  The options are of
                        Use the specified serial port.  The options are of

-                       the form "bbbbpn", where "bbbb" is the baud rate,
-                       "p" is parity ("n", "o", or "e"), and "n" is bits.
-                       Default is "9600n8".
+                       the form "bbbbpnf", where "bbbb" is the baud rate,
+                       "p" is parity ("n", "o", or "e"), "n" is number of
+                       bits, and "f" is flow control ("r" for RTS or
+                       omit it).  Default is "9600n8".

 
 

-                       See also Documentation/serial-console.txt.
+                       See Documentation/serial-console.txt for more
+                       information.  See
+                       Documentation/networking/netconsole.txt for an
+                       alternative.

 
                uart,io,<addr>[,options]
                uart,mmio,<addr>[,options]
 
                uart,io,<addr>[,options]
                uart,mmio,<addr>[,options]


@@ -406,13 +460,19 @@ running once the system is up.
 
        debug           [KNL] Enable kernel debugging (events log level).
 
 
        debug           [KNL] Enable kernel debugging (events log level).
 

+       debug_locks_verbose=
+                       [KNL] verbose self-tests
+                       Format=<0|1>
+                       Print debugging info while doing the locking API
+                       self-tests.
+                       We default to 0 (no extra messages), setting it to
+                       1 will print _a lot_ more information - normally
+                       only useful to kernel developers.
+

        decnet=         [HW,NET]
                        Format: <area>[,<node>]
                        See also Documentation/networking/decnet.txt.
 
        decnet=         [HW,NET]
                        Format: <area>[,<node>]
                        See also Documentation/networking/decnet.txt.
 

-       devfs=          [DEVFS]
-                       See Documentation/filesystems/devfs/boot-options.
-

        dhash_entries=  [KNL]
                        Set number of hash buckets for dentry cache.
 
        dhash_entries=  [KNL]
                        Set number of hash buckets for dentry cache.
 


@@ -433,7 +493,7 @@ running once the system is up.
 
        dtc3181e=       [HW,SCSI]
 
 
        dtc3181e=       [HW,SCSI]
 

-       earlyprintk=    [IA-32,X86-64]
+       earlyprintk=    [IA-32,X86-64,SH]

                        earlyprintk=vga
                        earlyprintk=serial[,ttySn[,baudrate]]
 
                        earlyprintk=vga
                        earlyprintk=serial[,ttySn[,baudrate]]
 


@@ -452,6 +512,11 @@ running once the system is up.
 
        eata=           [HW,SCSI]
 
 
        eata=           [HW,SCSI]
 

+       ec_intr=        [HW,ACPI] ACPI Embedded Controller interrupt mode
+                       Format: <int>
+                       0: polling mode
+                       non-0: interrupt mode (default)
+

        eda=            [HW,PS2]
 
        edb=            [HW,PS2]
        eda=            [HW,PS2]
 
        edb=            [HW,PS2]


@@ -471,14 +536,15 @@ running once the system is up.
                        arch/i386/kernel/cpu/cpufreq/elanfreq.c.
 
        elevator=       [IOSCHED]
                        arch/i386/kernel/cpu/cpufreq/elanfreq.c.
 
        elevator=       [IOSCHED]

-                       Format: {"as" | "cfq" | "deadline" | "noop"}
+                       Format: {"anticipatory" | "cfq" | "deadline" | "noop"}

                        See Documentation/block/as-iosched.txt and
                        Documentation/block/deadline-iosched.txt for details.
 
                        See Documentation/block/as-iosched.txt and
                        Documentation/block/deadline-iosched.txt for details.
 

-       elfcorehdr=     [IA-32]
+       elfcorehdr=     [IA-32, X86_64]

                        Specifies physical address of start of kernel core
                        Specifies physical address of start of kernel core

-                       image elf header.
-                       See Documentation/kdump.txt for details.
+                       image elf header. Generally kexec loader will
+                       pass this option to capture kernel.
+                       See Documentation/kdump/kdump.txt for details.

 
        enforcing       [SELINUX] Set initial enforcing status.
                        Format: {"0" | "1"}
 
        enforcing       [SELINUX] Set initial enforcing status.
                        Format: {"0" | "1"}


@@ -488,10 +554,6 @@ running once the system is up.
                        Default value is 0.
                        Value can be changed at runtime via /selinux/enforce.
 
                        Default value is 0.
                        Value can be changed at runtime via /selinux/enforce.
 

-       es1370=         [HW,OSS]
-                       Format: <lineout>[,<micbias>]
-                       See also header of sound/oss/es1370.c.
-

        es1371=         [HW,OSS]
                        Format: <spdif>,[<nomix>,[<amplifier>]]
                        See also header of sound/oss/es1371.c.
        es1371=         [HW,OSS]
                        Format: <spdif>,[<nomix>,[<amplifier>]]
                        See also header of sound/oss/es1371.c.


@@ -503,6 +565,13 @@ running once the system is up.
        eurwdt=         [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
                        Format: <io>[,<irq>]
 
        eurwdt=         [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
                        Format: <io>[,<irq>]
 

+       failslab=
+       fail_page_alloc=
+       fail_make_request=[KNL]
+                       General fault injection mechanism.
+                       Format: <interval>,<probability>,<space>,<times>
+                       See also /Documentation/fault-injection/.
+

        fd_mcs=         [HW,SCSI]
                        See header of drivers/scsi/fd_mcs.c.
 
        fd_mcs=         [HW,SCSI]
                        See header of drivers/scsi/fd_mcs.c.
 


@@ -512,9 +581,6 @@ running once the system is up.
        floppy=         [HW]
                        See Documentation/floppy.txt.
 
        floppy=         [HW]
                        See Documentation/floppy.txt.
 

-       ftape=          [HW] Floppy Tape subsystem debugging options.
-                       See Documentation/ftape.txt.
-

        gamecon.map[2|3]=
                        [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
                        support via parallel port (up to 5 devices per port)
        gamecon.map[2|3]=
                        [HW,JOY] Multisystem joystick and NES/SNES/PSX pad
                        support via parallel port (up to 5 devices per port)


@@ -532,11 +598,6 @@ running once the system is up.
        gscd=           [HW,CD]
                        Format: <io>
 
        gscd=           [HW,CD]
                        Format: <io>
 

-       gt96100eth=     [NET] MIPS GT96100 Advanced Communication Controller
-
-       gus=            [HW,OSS]
-                       Format: <io>,<irq>,<dma>,<dma16>
-

        gvp11=          [HW,SCSI]
 
        hashdist=       [KNL,NUMA] Large hashes allocated during boot
        gvp11=          [HW,SCSI]
 
        hashdist=       [KNL,NUMA] Large hashes allocated during boot


@@ -557,16 +618,18 @@ running once the system is up.
                        highmem otherwise. This also works to reduce highmem
                        size on bigger boxes.
 
                        highmem otherwise. This also works to reduce highmem
                        size on bigger boxes.
 

+       highres=        [KNL] Enable/disable high resolution timer mode.
+                       Valid parameters: "on", "off"
+                       Default: "on"
+

        hisax=          [HW,ISDN]
                        See Documentation/isdn/README.HiSax.
 
        hugepages=      [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
 
        hisax=          [HW,ISDN]
                        See Documentation/isdn/README.HiSax.
 
        hugepages=      [HW,IA-32,IA-64] Maximal number of HugeTLB pages.
 

-       noirqbalance    [IA-32,SMP,KNL] Disable kernel irq balancing
-

        i8042.direct    [HW] Put keyboard port into non-translated mode
        i8042.direct    [HW] Put keyboard port into non-translated mode

-       i8042.dumbkbd   [HW] Pretend that controlled can only read data from
-                            keyboard and can not control its state
+       i8042.dumbkbd   [HW] Pretend that controller can only read data from
+                            keyboard and cannot control its state

                             (Don't attempt to blink the leds)
        i8042.noaux     [HW] Don't check for auxiliary (== mouse) port
        i8042.nokbd     [HW] Don't check/create keyboard port
                             (Don't attempt to blink the leds)
        i8042.noaux     [HW] Don't check for auxiliary (== mouse) port
        i8042.nokbd     [HW] Don't check/create keyboard port


@@ -613,6 +676,10 @@ running once the system is up.
        idle=           [HW]
                        Format: idle=poll or idle=halt
 
        idle=           [HW]
                        Format: idle=poll or idle=halt
 

+       ignore_loglevel [KNL]
+                       Ignore loglevel setting - this will print /all/
+                       kernel messages to the console. Useful for debugging.
+

        ihash_entries=  [KNL]
                        Set number of hash buckets for inode cache.
 
        ihash_entries=  [KNL]
                        Set number of hash buckets for inode cache.
 


@@ -656,6 +723,12 @@ running once the system is up.
        ips=            [HW,SCSI] Adaptec / IBM ServeRAID controller
                        See header of drivers/scsi/ips.c.
 
        ips=            [HW,SCSI] Adaptec / IBM ServeRAID controller
                        See header of drivers/scsi/ips.c.
 

+       ports=          [IP_VS_FTP] IPVS ftp helper module
+                       Default is 21.
+                       Up to 8 (IP_VS_APP_MAX_PORTS) ports
+                       may be specified.
+                       Format: <port>,<port>....
+

        irqfixup        [HW]
                        When an interrupt is not handled search all handlers
                        for it. Intended to get systems with badly broken
        irqfixup        [HW]
                        When an interrupt is not handled search all handlers
                        for it. Intended to get systems with badly broken


@@ -671,7 +744,12 @@ running once the system is up.
                        Format: <RDP>,<reset>,<pci_scan>,<verbosity>
 
        isolcpus=       [KNL,SMP] Isolate CPUs from the general scheduler.
                        Format: <RDP>,<reset>,<pci_scan>,<verbosity>
 
        isolcpus=       [KNL,SMP] Isolate CPUs from the general scheduler.

-                       Format: <cpu number>,...,<cpu number>
+                       Format:
+                       <cpu number>,...,<cpu number>
+                       or
+                       <cpu number>-<cpu number>  (must be a positive range in ascending order)
+                       or a mixture
+                       <cpu number>,...,<cpu number>-<cpu number>

                        This option can be used to specify one or more CPUs
                        to isolate from the general SMP balancing and scheduling
                        algorithms. The only way to move a process onto or off
                        This option can be used to specify one or more CPUs
                        to isolate from the general SMP balancing and scheduling
                        algorithms. The only way to move a process onto or off


@@ -702,6 +780,9 @@ running once the system is up.
        lapic           [IA-32,APIC] Enable the local APIC even if BIOS
                        disabled it.
 
        lapic           [IA-32,APIC] Enable the local APIC even if BIOS
                        disabled it.
 

+       lapic_timer_c2_ok       [IA-32,x86-64,APIC] trust the local apic timer in
+                       C2 power state.
+

        lasi=           [HW,SCSI] PARISC LASI driver for the 53c700 chip
                        Format: addr:<io>,irq:<irq>
 
        lasi=           [HW,SCSI] PARISC LASI driver for the 53c700 chip
                        Format: addr:<io>,irq:<irq>
 


@@ -711,9 +792,17 @@ running once the system is up.
        load_ramdisk=   [RAM] List of ramdisks to load from floppy
                        See Documentation/ramdisk.txt.
 
        load_ramdisk=   [RAM] List of ramdisks to load from floppy
                        See Documentation/ramdisk.txt.
 

-       lockd.udpport=  [NFS]
+       lockd.nlm_grace_period=P  [NFS] Assign grace period.
+                       Format: <integer>
+
+       lockd.nlm_tcpport=N     [NFS] Assign TCP port.
+                       Format: <integer>

 
 

-       lockd.tcpport=  [NFS]
+       lockd.nlm_timeout=T     [NFS] Assign timeout value.
+                       Format: <integer>
+
+       lockd.nlm_udpport=M     [NFS] Assign UDP port.
+                       Format: <integer>

 
        logibm.irq=     [HW,MOUSE] Logitech Bus Mouse Driver
                        Format: <irq>
 
        logibm.irq=     [HW,MOUSE] Logitech Bus Mouse Driver
                        Format: <irq>


@@ -781,18 +870,19 @@ running once the system is up.
                        (machvec) in a generic kernel.
                        Example: machvec=hpzx1_swiotlb
 
                        (machvec) in a generic kernel.
                        Example: machvec=hpzx1_swiotlb
 

-       mad16=          [HW,OSS] Format:
-                       <io>,<irq>,<dma>,<dma16>,<mpu_io>,<mpu_irq>,<joystick>
-
-       maui=           [HW,OSS]
-                       Format: <io>,<irq>
-

        max_loop=       [LOOP] Maximum number of loopback devices that can
                        be mounted
                        Format: <1-256>
 
        maxcpus=        [SMP] Maximum number of processors that an SMP kernel
        max_loop=       [LOOP] Maximum number of loopback devices that can
                        be mounted
                        Format: <1-256>
 
        maxcpus=        [SMP] Maximum number of processors that an SMP kernel

-                       should make use of
+                       should make use of.
+                       Using "nosmp" or "maxcpus=0" will disable SMP
+                       entirely (the MPS table probe still happens, though).
+                       A command-line option of "maxcpus=<NUM>", where <NUM>
+                       is an integer greater than 0, limits the maximum number
+                       of CPUs activated in SMP mode to <NUM>.
+                       Using "maxcpus=1" on an SMP kernel is the trivial
+                       case of an SMP kernel with only one CPU.

 
        max_addr=[KMG]  [KNL,BOOT,ia64] All physical memory greater than or
                        equal to this physical address is ignored.
 
        max_addr=[KMG]  [KNL,BOOT,ia64] All physical memory greater than or
                        equal to this physical address is ignored.


@@ -832,7 +922,7 @@ running once the system is up.
        mem=nopentium   [BUGS=IA-32] Disable usage of 4MB pages for kernel
                        memory.
 
        mem=nopentium   [BUGS=IA-32] Disable usage of 4MB pages for kernel
                        memory.
 

-       memmap=exactmap [KNL,IA-32] Enable setting of an exact
+       memmap=exactmap [KNL,IA-32,X86_64] Enable setting of an exact

                        E820 memory map, as specified by the user.
                        Such memmap=exactmap lines can be constructed based on
                        BIOS output or other requirements. See the memmap=nn@ss
                        E820 memory map, as specified by the user.
                        Such memmap=exactmap lines can be constructed based on
                        BIOS output or other requirements. See the memmap=nn@ss


@@ -855,6 +945,49 @@ running once the system is up.
 
        mga=            [HW,DRM]
 
 
        mga=            [HW,DRM]
 

+       migration_cost=
+                       [KNL,SMP] debug: override scheduler migration costs
+                       Format: <level-1-usecs>,<level-2-usecs>,...
+                       This debugging option can be used to override the
+                       default scheduler migration cost matrix. The numbers
+                       are indexed by 'CPU domain distance'.
+                       E.g. migration_cost=1000,2000,3000 on an SMT NUMA
+                       box will set up an intra-core migration cost of
+                       1 msec, an inter-core migration cost of 2 msecs,
+                       and an inter-node migration cost of 3 msecs.
+
+                       WARNING: using the wrong values here can break
+                       scheduler performance, so it's only for scheduler
+                       development purposes, not production environments.
+
+       migration_debug=
+                       [KNL,SMP] migration cost auto-detect verbosity
+                       Format=<0|1|2>
+                       If a system's migration matrix reported at bootup
+                       seems erroneous then this option can be used to
+                       increase verbosity of the detection process.
+                       We default to 0 (no extra messages), 1 will print
+                       some more information, and 2 will be really
+                       verbose (probably only useful if you also have a
+                       serial console attached to the system).
+
+       migration_factor=
+                       [KNL,SMP] multiply/divide migration costs by a factor
+                       Format=<percent>
+                       This debug option can be used to proportionally
+                       increase or decrease the auto-detected migration
+                       costs for all entries of the migration matrix.
+                       E.g. migration_factor=150 will increase migration
+                       costs by 50%. (and thus the scheduler will be less
+                       eager migrating cache-hot tasks)
+                       migration_factor=80 will decrease migration costs
+                       by 20%. (thus the scheduler will be more eager to
+                       migrate tasks)
+
+                       WARNING: using the wrong values here can break
+                       scheduler performance, so it's only for scheduler
+                       development purposes, not production environments.
+

        mousedev.tap_time=
                        [MOUSE] Maximum time between finger touching and
                        leaving touchpad surface for touch to be considered
        mousedev.tap_time=
                        [MOUSE] Maximum time between finger touching and
                        leaving touchpad surface for touch to be considered


@@ -910,12 +1043,28 @@ running once the system is up.
        nfsroot=        [NFS] nfs root filesystem for disk-less boxes.
                        See Documentation/nfsroot.txt.
 
        nfsroot=        [NFS] nfs root filesystem for disk-less boxes.
                        See Documentation/nfsroot.txt.
 

+       nfs.callback_tcpport=
+                       [NFS] set the TCP port on which the NFSv4 callback
+                       channel should listen.
+
+       nfs.idmap_cache_timeout=
+                       [NFS] set the maximum lifetime for idmapper cache
+                       entries.
+

        nmi_watchdog=   [KNL,BUGS=IA-32] Debugging features for SMP kernels
 
        no387           [BUGS=IA-32] Tells the kernel to use the 387 maths
                        emulation library even if a 387 maths coprocessor
                        is present.
 
        nmi_watchdog=   [KNL,BUGS=IA-32] Debugging features for SMP kernels
 
        no387           [BUGS=IA-32] Tells the kernel to use the 387 maths
                        emulation library even if a 387 maths coprocessor
                        is present.
 

+       noacpi          [LIBATA] Disables use of ACPI in libata suspend/resume
+                       when set.
+                       Format: <int>
+
+       noaliencache    [MM, NUMA] Disables the allcoation of alien caches in
+                       the slab allocator.  Saves per-node memory, but will
+                       impact performance on real NUMA hardware.
+

        noalign         [KNL,ARM]
 
        noapic          [SMP,APIC] Tells the kernel to not make use of any
        noalign         [KNL,ARM]
 
        noapic          [SMP,APIC] Tells the kernel to not make use of any


@@ -929,6 +1078,8 @@ running once the system is up.
 
        nocache         [ARM]
 
 
        nocache         [ARM]
 

+       nodelayacct     [KNL] Disable per-task delay accounting
+

        nodisconnect    [HW,SCSI,M68K] Disables SCSI disconnects.
 
        noexec          [IA-64]
        nodisconnect    [HW,SCSI,M68K] Disables SCSI disconnects.
 
        noexec          [IA-64]


@@ -937,7 +1088,9 @@ running once the system is up.
                        noexec=on: enable non-executable mappings (default)
                        noexec=off: disable nn-executable mappings
 
                        noexec=on: enable non-executable mappings (default)
                        noexec=off: disable nn-executable mappings
 

-       nofxsr          [BUGS=IA-32]
+       nofxsr          [BUGS=IA-32] Disables x86 floating point extended
+                       register save and restore. The kernel will only save
+                       legacy floating-point registers on task switch.

 
        nohlt           [BUGS=ARM]
 
 
        nohlt           [BUGS=ARM]
 


@@ -952,9 +1105,18 @@ running once the system is up.
                        in certain environments such as networked servers or
                        real-time systems.
 
                        in certain environments such as networked servers or
                        real-time systems.
 

+       nohz=           [KNL] Boottime enable/disable dynamic ticks
+                       Valid arguments: on, off
+                       Default: on
+
+       noirqbalance    [IA-32,SMP,KNL] Disable kernel irq balancing
+

        noirqdebug      [IA-32] Disables the code which attempts to detect and
                        disable unhandled interrupt sources.
 
        noirqdebug      [IA-32] Disables the code which attempts to detect and
                        disable unhandled interrupt sources.
 

+       no_timer_check  [IA-32,X86_64,APIC] Disables the code which tests for
+                       broken timer IRQ sources.
+

        noisapnp        [ISAPNP] Disables ISA PnP code.
 
        noinitrd        [RAM] Tells the kernel not to load any configured
        noisapnp        [ISAPNP] Disables ISA PnP code.
 
        noinitrd        [RAM] Tells the kernel not to load any configured


@@ -964,9 +1126,13 @@ running once the system is up.
 
        nolapic         [IA-32,APIC] Do not enable or use the local APIC.
 
 
        nolapic         [IA-32,APIC] Do not enable or use the local APIC.
 

+       nolapic_timer   [IA-32,APIC] Do not use the local APIC timer.
+

        noltlbs         [PPC] Do not use large page/tlb entries for kernel
                        lowmem mapping on PPC40x.
 
        noltlbs         [PPC] Do not use large page/tlb entries for kernel
                        lowmem mapping on PPC40x.
 

+       nomca           [IA-64] Disable machine check abort handling
+

        nomce           [IA-32] Machine Check Exception
 
        noresidual      [PPC] Don't use residual data on PReP machines.
        nomce           [IA-32] Machine Check Exception
 
        noresidual      [PPC] Don't use residual data on PReP machines.


@@ -980,6 +1146,8 @@ running once the system is up.
 
        nosbagart       [IA-64]
 
 
        nosbagart       [IA-64]
 

+       nosep           [BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
+

        nosmp           [SMP] Tells an SMP kernel to act as a UP kernel.
 
        nosync          [HW,M68K] Disables sync negotiation for all devices.
        nosmp           [SMP] Tells an SMP kernel to act as a UP kernel.
 
        nosync          [HW,M68K] Disables sync negotiation for all devices.


@@ -990,12 +1158,11 @@ running once the system is up.
 
        nowb            [ARM]
 
 
        nowb            [ARM]
 

+       nr_uarts=       [SERIAL] maximum number of UARTs to be registered.
+

        opl3=           [HW,OSS]
                        Format: <io>
 
        opl3=           [HW,OSS]
                        Format: <io>
 

-       opl3sa=         [HW,OSS]
-                       Format: <io>,<irq>,<dma>,<dma2>,<mpu_io>,<mpu_irq>
-

        opl3sa2=        [HW,OSS] Format:
                        <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
 
        opl3sa2=        [HW,OSS] Format:
                        <io>,<irq>,<dma>,<dma2>,<mss_io>,<mpu_io>,<ymode>,<loopback>[,<isapnp>,<multiple]
 


@@ -1047,6 +1214,11 @@ running once the system is up.
        pas16=          [HW,SCSI]
                        See header of drivers/scsi/pas16.c.
 
        pas16=          [HW,SCSI]
                        See header of drivers/scsi/pas16.c.
 

+       pause_on_oops=
+                       Halt all CPUs after the first oops has been printed for
+                       the specified number of seconds.  This is to be used if
+                       your oopses keep scrolling off the screen.
+

        pcbit=          [HW,ISDN]
 
        pcd.            [PARIDE]
        pcbit=          [HW,ISDN]
 
        pcd.            [PARIDE]


@@ -1066,6 +1238,11 @@ running once the system is up.
                                Mechanism 1.
                conf2           [IA-32] Force use of PCI Configuration
                                Mechanism 2.
                                Mechanism 1.
                conf2           [IA-32] Force use of PCI Configuration
                                Mechanism 2.

+               nommconf        [IA-32,X86_64] Disable use of MMCONFIG for PCI
+                               Configuration
+               nomsi           [MSI] If the PCI_MSI kernel config parameter is
+                               enabled, this kernel boot option can be used to
+                               disable the use of MSI interrupts system-wide.

                nosort          [IA-32] Don't sort PCI devices according to
                                order given by the PCI BIOS. This sorting is
                                done to get a device order compatible with
                nosort          [IA-32] Don't sort PCI devices according to
                                order given by the PCI BIOS. This sorting is
                                done to get a device order compatible with


@@ -1114,6 +1291,21 @@ running once the system is up.
                                bootloader. This is currently used on
                                IXP2000 systems where the bus has to be
                                configured a certain way for adjunct CPUs.
                                bootloader. This is currently used on
                                IXP2000 systems where the bus has to be
                                configured a certain way for adjunct CPUs.

+               noearly         [X86] Don't do any early type 1 scanning.
+                               This might help on some broken boards which
+                               machine check when some devices' config space
+                               is read. But various workarounds are disabled
+                               and some IOMMU drivers will not work.
+               bfsort          Sort PCI devices into breadth-first order.
+                               This sorting is done to get a device
+                               order compatible with older (<= 2.4) kernels.
+               nobfsort        Don't sort PCI devices into breadth-first order.
+               cbiosize=nn[KMG]        The fixed amount of bus space which is
+                               reserved for the CardBus bridge's IO window.
+                               The default value is 256 bytes.
+               cbmemsize=nn[KMG]       The fixed amount of bus space which is
+                               reserved for the CardBus bridge's memory
+                               window. The default value is 64 megabytes.

 
        pcmv=           [HW,PCMCIA] BadgePAD 4
 
 
        pcmv=           [HW,PCMCIA] BadgePAD 4
 


@@ -1163,6 +1355,7 @@ running once the system is up.
                        Param: "schedule" - profile schedule points.
                        Param: <number> - step/bucket size as a power of 2 for
                                statistical time based profiling.
                        Param: "schedule" - profile schedule points.
                        Param: <number> - step/bucket size as a power of 2 for
                                statistical time based profiling.

+                       Param: "sleep" - profile D-state sleeping (millisecs)

 
        processor.max_cstate=   [HW,ACPI]
                        Limit processor to maximum C-state
 
        processor.max_cstate=   [HW,ACPI]
                        Limit processor to maximum C-state


@@ -1196,7 +1389,7 @@ running once the system is up.
        pt.             [PARIDE]
                        See Documentation/paride.txt.
 
        pt.             [PARIDE]
                        See Documentation/paride.txt.
 

-       quiet=          [KNL] Disable log messages
+       quiet           [KNL] Disable most log messages

 
        r128=           [HW,DRM]
 
 
        r128=           [HW,DRM]
 


@@ -1213,6 +1406,15 @@ running once the system is up.
                        New name for the ramdisk parameter.
                        See Documentation/ramdisk.txt.
 
                        New name for the ramdisk parameter.
                        See Documentation/ramdisk.txt.
 

+       rcu.blimit=     [KNL,BOOT] Set maximum number of finished
+                       RCU callbacks to process in one batch.
+
+       rcu.qhimark=    [KNL,BOOT] Set threshold of queued
+                       RCU callbacks over which batch limiting is disabled.
+
+       rcu.qlowmark=   [KNL,BOOT] Set threshold of queued
+                       RCU callbacks below which batch limiting is re-enabled.
+

        rdinit=         [KNL]
                        Format: <full_path>
                        Run specified binary instead of /init from the ramdisk,
        rdinit=         [KNL]
                        Format: <full_path>
                        Run specified binary instead of /init from the ramdisk,


@@ -1220,13 +1422,29 @@ running once the system is up.
 
        reboot=         [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
                        Format: <reboot_mode>[,<reboot_mode2>[,...]]
 
        reboot=         [BUGS=IA-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
                        Format: <reboot_mode>[,<reboot_mode2>[,...]]

-                       See arch/*/kernel/reboot.c.
+                       See arch/*/kernel/reboot.c or arch/*/kernel/process.c                   

 
        reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
 
 
        reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
 

+       reservetop=     [IA-32]
+                       Format: nn[KMG]
+                       Reserves a hole at the top of the kernel virtual
+                       address space.
+
+       reset_devices   [KNL] Force drivers to reset the underlying device
+                       during initialization.
+

        resume=         [SWSUSP]
                        Specify the partition device for software suspend
 
        resume=         [SWSUSP]
                        Specify the partition device for software suspend
 

+       resume_offset=  [SWSUSP]
+                       Specify the offset from the beginning of the partition
+                       given by "resume=" at which the swap header is located,
+                       in <PAGE_SIZE> units (needed only for swap files).
+                       See  Documentation/power/swsusp-and-swap-files.txt
+
+       retain_initrd   [RAM] Keep initrd memory after extraction
+

        rhash_entries=  [KNL,NET]
                        Set number of hash buckets for route cache
 
        rhash_entries=  [KNL,NET]
                        Set number of hash buckets for route cache
 


@@ -1277,6 +1495,11 @@ running once the system is up.
 
        scsi_logging=   [SCSI]
 
 
        scsi_logging=   [SCSI]
 

+       scsi_mod.scan=  [SCSI] sync (default) scans SCSI busses as they are
+                       discovered.  async scans them in kernel threads,
+                       allowing boot to proceed.  none ignores them, expecting
+                       user space to do the scan.
+

        selinux         [SELINUX] Disable or enable SELinux at boot time.
                        Format: { "0" | "1" }
                        See security/selinux/Kconfig help text.
        selinux         [SELINUX] Disable or enable SELinux at boot time.
                        Format: { "0" | "1" }
                        See security/selinux/Kconfig help text.


@@ -1286,13 +1509,19 @@ running once the system is up.
                        If enabled at boot time, /selinux/disable can be used
                        later to disable prior to initial policy load.
 
                        If enabled at boot time, /selinux/disable can be used
                        later to disable prior to initial policy load.
 

+       selinux_compat_net =
+                       [SELINUX] Set initial selinux_compat_net flag value.
+                        Format: { "0" | "1" }
+                        0 -- use new secmark-based packet controls
+                        1 -- use legacy packet controls
+                        Default value is 0 (preferred).
+                        Value can be changed at runtime via
+                        /selinux/compat_net.
+

        serialnumber    [BUGS=IA-32]
 
        sg_def_reserved_size=   [SCSI]
 
        serialnumber    [BUGS=IA-32]
 
        sg_def_reserved_size=   [SCSI]
 

-       sgalaxy=        [HW,OSS]
-                       Format: <io>,<irq>,<dma>,<dma2>,<sgbase>
-

        shapers=        [NET]
                        Maximal number of shapers.
 
        shapers=        [NET]
                        Maximal number of shapers.
 


@@ -1433,9 +1662,6 @@ running once the system is up.
 
        snd-ymfpci=     [HW,ALSA]
 
 
        snd-ymfpci=     [HW,ALSA]
 

-       sonicvibes=     [HW,OSS]
-                       Format: <reverb>
-

        sonycd535=      [HW,CD]
                        Format: <io>[,<irq>]
 
        sonycd535=      [HW,CD]
                        Format: <io>[,<irq>]
 


@@ -1472,6 +1698,22 @@ running once the system is up.
        stifb=          [HW]
                        Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
 
        stifb=          [HW]
                        Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
 

+       sunrpc.pool_mode=
+                       [NFS]
+                       Control how the NFS server code allocates CPUs to
+                       service thread pools.  Depending on how many NICs
+                       you have and where their interrupts are bound, this
+                       option will affect which CPUs will do NFS serving.
+                       Note: this parameter cannot be changed while the
+                       NFS server is running.
+
+                       auto        the server chooses an appropriate mode
+                                   automatically using heuristics
+                       global      a single global pool contains all CPUs
+                       percpu      one pool for each CPU
+                       pernode     one pool for each NUMA node (equivalent
+                                   to global on non-NUMA machines)
+

        swiotlb=        [IA-64] Number of I/O TLB slabs
 
        switches=       [HW,M68k]
        swiotlb=        [IA-64] Number of I/O TLB slabs
 
        switches=       [HW,M68k]


@@ -1479,6 +1721,12 @@ running once the system is up.
        sym53c416=      [HW,SCSI]
                        See header of drivers/scsi/sym53c416.c.
 
        sym53c416=      [HW,SCSI]
                        See header of drivers/scsi/sym53c416.c.
 

+       sysrq_always_enabled
+                       [KNL]
+                       Ignore sysrq setting - this boot parameter will
+                       neutralize any effect of /proc/sys/kernel/sysrq.
+                       Useful for debugging.
+

        t128=           [HW,SCSI]
                        See header of drivers/scsi/t128.c.
 
        t128=           [HW,SCSI]
                        See header of drivers/scsi/t128.c.
 


@@ -1489,6 +1737,10 @@ running once the system is up.
 
        time            Show timing data prefixed to each printk message line
 
 
        time            Show timing data prefixed to each printk message line
 

+       clocksource=    [GENERIC_TIME] Override the default clocksource
+                       Override the default clocksource and use the clocksource
+                       with the name specified.
+

        tipar.timeout=  [HW,PPT]
                        Set communications timeout in tenths of a second
                        (default 15).
        tipar.timeout=  [HW,PPT]
                        Set communications timeout in tenths of a second
                        (default 15).


@@ -1527,9 +1779,28 @@ running once the system is up.
        uart6850=       [HW,OSS]
                        Format: <io>,<irq>
 
        uart6850=       [HW,OSS]
                        Format: <io>,<irq>
 

+       uhci-hcd.ignore_oc=
+                       [USB] Ignore overcurrent events (default N).
+                       Some badly-designed motherboards generate lots of
+                       bogus events, for ports that aren't wired to
+                       anything.  Set this parameter to avoid log spamming.
+                       Note that genuine overcurrent events won't be
+                       reported either.
+
+       usbcore.autosuspend=
+                       [USB] The autosuspend time delay (in seconds) used
+                       for newly-detected USB devices (default 2).  This
+                       is the time required before an idle device will be
+                       autosuspended.  Devices for which the delay is set
+                       to 0 won't be autosuspended at all.
+

        usbhid.mousepoll=
                        [USBHID] The interval which mice are to be polled at.
 
        usbhid.mousepoll=
                        [USBHID] The interval which mice are to be polled at.
 

+       vdso=           [IA-32,SH]
+                       vdso=1: enable VDSO (default)
+                       vdso=0: disable VDSO mapping
+

        video=          [FB] Frame buffer configuration
                        See Documentation/fb/modedb.txt.
 
        video=          [FB] Frame buffer configuration
                        See Documentation/fb/modedb.txt.
 


@@ -1546,9 +1817,14 @@ running once the system is up.
                        decrease the size and leave more room for directly
                        mapped kernel RAM.
 
                        decrease the size and leave more room for directly
                        mapped kernel RAM.
 

-       vmhalt=         [KNL,S390]
+       vmhalt=         [KNL,S390] Perform z/VM CP command after system halt.
+                       Format: <command>
+
+       vmpanic=        [KNL,S390] Perform z/VM CP command after kernel panic.
+                       Format: <command>

 
 

-       vmpoff=         [KNL,S390]
+       vmpoff=         [KNL,S390] Perform z/VM CP command after power off.
+                       Format: <command>

 
        waveartist=     [HW,OSS]
                        Format: <io>,<irq>,<dma>,<dma2>
 
        waveartist=     [HW,OSS]
                        Format: <io>,<irq>,<dma>,<dma2>


@@ -1569,22 +1845,14 @@ running once the system is up.
                        Format:
                        <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
 
                        Format:
                        <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
 

+       norandmaps      Don't use address space randomization
+                       Equivalent to echo 0 > /proc/sys/kernel/randomize_va_space

 
 

-______________________________________________________________________
-Changelog:
-
-2000-06-??     Mr. Unknown
-       The last known update (for 2.4.0) - the changelog was not kept before.
+       unwind_debug=N  N > 0 will enable dwarf2 unwinder debugging
+                       This is useful to get more information why
+                       you got a "dwarf2 unwinder stuck"

 
 

-2002-11-24     Petr Baudis <pasky@ucw.cz>
-               Randy Dunlap <randy.dunlap@verizon.net>
-       Update for 2.5.49, description for most of the options introduced,
-       references to other documentation (C files, READMEs, ..), added S390,
-       PPC, SPARC, MTD, ALSA and OSS category. Minor corrections and
-       reformatting.
-
-2005-10-19     Randy Dunlap <rdunlap@xenotime.net>
-       Lots of typos, whitespace, some reformatting.
+______________________________________________________________________

 
 TODO:
 
 
 TODO: