Merge branches 'x86/apic', 'x86/cleanups', 'x86/cpufeature', 'x86/crashdump', 'x86...
[sfrench/cifs-2.6.git] / Documentation / kernel-parameters.txt
index c86c074597129a5b4434b0e35c432a0a28636b11..d5418d52891027c6ef25277b253b98965be94451 100644 (file)
@@ -198,59 +198,42 @@ and is between 256 and 4096 characters. It is defined in the file
                        that require a timer override, but don't have
                        HPET
 
-       acpi.debug_layer=       [HW,ACPI]
+       acpi_backlight= [HW,ACPI]
+                       acpi_backlight=vendor
+                       acpi_backlight=video
+                       If set to vendor, prefer vendor specific driver
+                       (e.g. thinkpad_acpi, sony_acpi, etc.) instead
+                       of the ACPI video.ko driver.
+
+       acpi_display_output=    [HW,ACPI]
+                       acpi_display_output=vendor
+                       acpi_display_output=video
+                       See above.
+
+       acpi.debug_layer=       [HW,ACPI,ACPI_DEBUG]
+       acpi.debug_level=       [HW,ACPI,ACPI_DEBUG]
                        Format: <int>
-                       Each bit of the <int> indicates an ACPI debug layer,
-                       1: enable, 0: disable. It is useful for boot time
-                       debugging. After system has booted up, it can be set
-                       via /sys/module/acpi/parameters/debug_layer.
-                       CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
-                       Available bits (add the numbers together) to enable debug output
-                       for specific parts of the ACPI subsystem:
-                       0x01 utilities 0x02 hardware 0x04 events 0x08 tables
-                       0x10 namespace 0x20 parser 0x40 dispatcher
-                       0x80 executer 0x100 resources 0x200 acpica debugger
-                       0x400 os services 0x800 acpica disassembler.
-                       The number can be in decimal or prefixed with 0x in hex.
-                       Warning: Many of these options can produce a lot of
-                       output and make your system unusable. Be very careful.
-
-       acpi.debug_level=       [HW,ACPI]
-                       Format: <int>
-                       Each bit of the <int> indicates an ACPI debug level,
-                       which corresponds to the level in an ACPI_DEBUG_PRINT
-                       statement.  After system has booted up, this mask
-                       can be set via /sys/module/acpi/parameters/debug_level.
-
-                       CONFIG_ACPI_DEBUG must be enabled for this to produce
-                       any output.  The number can be in decimal or prefixed
-                       with 0x in hex.  Some of these options produce so much
-                       output that the system is unusable.
-
-                       The following global components are defined by the
-                       ACPI CA:
-                              0x01 error
-                              0x02 warn
-                              0x04 init
-                              0x08 debug object
-                              0x10 info
-                              0x20 init names
-                              0x40 parse
-                              0x80 load
-                             0x100 dispatch
-                             0x200 execute
-                             0x400 names
-                             0x800 operation region
-                            0x1000 bfield
-                            0x2000 tables
-                            0x4000 values
-                            0x8000 objects
-                           0x10000 resources
-                           0x20000 user requests
-                           0x40000 package
-                       The number can be in decimal or prefixed with 0x in hex.
-                       Warning: Many of these options can produce a lot of
-                       output and make your system unusable. Be very careful.
+                       CONFIG_ACPI_DEBUG must be enabled to produce any ACPI
+                       debug output.  Bits in debug_layer correspond to a
+                       _COMPONENT in an ACPI source file, e.g.,
+                           #define _COMPONENT ACPI_PCI_COMPONENT
+                       Bits in debug_level correspond to a level in
+                       ACPI_DEBUG_PRINT statements, e.g.,
+                           ACPI_DEBUG_PRINT((ACPI_DB_INFO, ...
+                       See Documentation/acpi/debug.txt for more information
+                       about debug layers and levels.
+
+                       Enable AML "Debug" output, i.e., stores to the Debug
+                       object while interpreting AML:
+                           acpi.debug_layer=0xffffffff acpi.debug_level=0x2
+                       Enable PCI/PCI interrupt routing info messages:
+                           acpi.debug_layer=0x400000 acpi.debug_level=0x4
+                       Enable all messages related to ACPI hardware:
+                           acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
+
+                       Some values produce so much output that the system is
+                       unusable.  The "log_buf_len" parameter may be useful
+                       if you need to capture more output.
 
        acpi.power_nocheck=     [HW,ACPI]
                        Format: 1/0 enable/disable the check of power state.
@@ -311,7 +294,9 @@ and is between 256 and 4096 characters. It is defined in the file
                        Possible values are:
                        isolate - enable device isolation (each device, as far
                                  as possible, will get its own protection
-                                 domain)
+                                 domain) [default]
+                       share - put every device behind one IOMMU into the
+                               same protection domain
                        fullflush - enable flushing of IO/TLB entries when
                                    they are unmapped. Otherwise they are
                                    flushed before they will be reused, which
@@ -646,7 +631,7 @@ and is between 256 and 4096 characters. It is defined in the file
 
        digiepca=       [HW,SERIAL]
                        See drivers/char/README.epca and
-                       Documentation/digiepca.txt.
+                       Documentation/serial/digiepca.txt.
 
        disable_mtrr_cleanup [X86]
        enable_mtrr_cleanup [X86]
@@ -757,7 +742,7 @@ and is between 256 and 4096 characters. It is defined in the file
                        See header of drivers/scsi/fdomain.c.
 
        floppy=         [HW]
-                       See Documentation/floppy.txt.
+                       See Documentation/blockdev/floppy.txt.
 
        force_pal_cache_flush
                        [IA-64] Avoid check_sal_cache_flush which may hang on
@@ -1118,7 +1103,7 @@ and is between 256 and 4096 characters. It is defined in the file
                        the same attribute, the last one is used.
 
        load_ramdisk=   [RAM] List of ramdisks to load from floppy
-                       See Documentation/ramdisk.txt.
+                       See Documentation/blockdev/ramdisk.txt.
 
        lockd.nlm_grace_period=P  [NFS] Assign grace period.
                        Format: <integer>
@@ -1210,8 +1195,8 @@ and is between 256 and 4096 characters. It is defined in the file
                        it is equivalent to "nosmp", which also disables
                        the IO APIC.
 
-       max_addr=[KMG]  [KNL,BOOT,ia64] All physical memory greater than or
-                       equal to this physical address is ignored.
+       max_addr=nn[KMG]        [KNL,BOOT,ia64] All physical memory greater than
+                       or equal to this physical address is ignored.
 
        max_luns=       [SCSI] Maximum number of LUNs to probe.
                        Should be between 1 and 2^32-1.
@@ -1311,6 +1296,9 @@ and is between 256 and 4096 characters. It is defined in the file
 
        mga=            [HW,DRM]
 
+       min_addr=nn[KMG]        [KNL,BOOT,ia64] All physical memory below this
+                       physical address is ignored.
+
        mminit_loglevel=
                        [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
                        parameter allows control of the logging verbosity for
@@ -1405,7 +1393,20 @@ and is between 256 and 4096 characters. It is defined in the file
                        when a NMI is triggered.
                        Format: [state][,regs][,debounce][,die]
 
-       nmi_watchdog=   [KNL,BUGS=X86-32] Debugging features for SMP kernels
+       nmi_watchdog=   [KNL,BUGS=X86-32,X86-64] Debugging features for SMP kernels
+                       Format: [panic,][num]
+                       Valid num: 0,1,2
+                       0 - turn nmi_watchdog off
+                       1 - use the IO-APIC timer for the NMI watchdog
+                       2 - use the local APIC for the NMI watchdog using
+                       a performance counter. Note: This will use one performance
+                       counter and the local APIC's performance vector.
+                       When panic is specified panic when an NMI watchdog timeout occurs.
+                       This is useful when you use a panic=... timeout and need the box
+                       quickly up again.
+                       Instead of 1 and 2 it is possible to use the following
+                       symbolic names: lapic and ioapic
+                       Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic
 
        no387           [BUGS=X86-32] Tells the kernel to use the 387 maths
                        emulation library even if a 387 maths coprocessor
@@ -1613,7 +1614,7 @@ and is between 256 and 4096 characters. It is defined in the file
 
        pcd.            [PARIDE]
                        See header of drivers/block/paride/pcd.c.
-                       See also Documentation/paride.txt.
+                       See also Documentation/blockdev/paride.txt.
 
        pci=option[,option...]  [PCI] various PCI subsystem options:
                off             [X86] don't probe for the PCI bus
@@ -1638,6 +1639,17 @@ and is between 256 and 4096 characters. It is defined in the file
                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.
+               noioapicquirk   [APIC] Disable all boot interrupt quirks.
+                               Safety option to keep boot IRQs enabled. This
+                               should never be necessary.
+               ioapicreroute   [APIC] Enable rerouting of boot IRQs to the
+                               primary IO-APIC for bridges that cannot disable
+                               boot IRQs. This fixes a source of spurious IRQs
+                               when the system masks IRQs.
+               noioapicreroute [APIC] Disable workaround that uses the
+                               boot IRQ equivalent of an IRQ that connects to
+                               a chipset where boot IRQs cannot be disabled.
+                               The opposite of ioapicreroute.
                biosirq         [X86-32] Use PCI BIOS calls to get the interrupt
                                routing table. These calls are known to be buggy
                                on several machines and they hang the machine
@@ -1714,7 +1726,7 @@ and is between 256 and 4096 characters. It is defined in the file
        pcmv=           [HW,PCMCIA] BadgePAD 4
 
        pd.             [PARIDE]
-                       See Documentation/paride.txt.
+                       See Documentation/blockdev/paride.txt.
 
        pdcchassis=     [PARISC,HW] Disable/Enable PDC Chassis Status codes at
                        boot time.
@@ -1722,10 +1734,10 @@ and is between 256 and 4096 characters. It is defined in the file
                        See arch/parisc/kernel/pdc_chassis.c
 
        pf.             [PARIDE]
-                       See Documentation/paride.txt.
+                       See Documentation/blockdev/paride.txt.
 
        pg.             [PARIDE]
-                       See Documentation/paride.txt.
+                       See Documentation/blockdev/paride.txt.
 
        pirq=           [SMP,APIC] Manual mp-table setup
                        See Documentation/x86/i386/IO-APIC.txt.
@@ -1795,7 +1807,7 @@ and is between 256 and 4096 characters. It is defined in the file
 
        prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
                        before loading.
-                       See Documentation/ramdisk.txt.
+                       See Documentation/blockdev/ramdisk.txt.
 
        psmouse.proto=  [HW,MOUSE] Highest PS2 mouse protocol extension to
                        probe for; one of (bare|imps|exps|lifebook|any).
@@ -1815,7 +1827,7 @@ and is between 256 and 4096 characters. It is defined in the file
                        <io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
 
        pt.             [PARIDE]
-                       See Documentation/paride.txt.
+                       See Documentation/blockdev/paride.txt.
 
        pty.legacy_count=
                        [KNL] Number of legacy pty's. Overwrites compiled-in
@@ -1829,10 +1841,10 @@ and is between 256 and 4096 characters. It is defined in the file
                        See Documentation/md.txt.
 
        ramdisk_blocksize=      [RAM]
-                       See Documentation/ramdisk.txt.
+                       See Documentation/blockdev/ramdisk.txt.
 
        ramdisk_size=   [RAM] Sizes of RAM disks in kilobytes
-                       See Documentation/ramdisk.txt.
+                       See Documentation/blockdev/ramdisk.txt.
 
        rcupdate.blimit=        [KNL,BOOT]
                        Set maximum number of finished RCU callbacks to process
@@ -2164,7 +2176,7 @@ and is between 256 and 4096 characters. It is defined in the file
                        See Documentation/sonypi.txt
 
        specialix=      [HW,SERIAL] Specialix multi-serial port adapter
-                       See Documentation/specialix.txt.
+                       See Documentation/serial/specialix.txt.
 
        spia_io_base=   [HW,MTD]
        spia_fio_base=
@@ -2267,6 +2279,13 @@ and is between 256 and 4096 characters. It is defined in the file
                        Format:
                        <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
 
+       tsc=            Disable clocksource-must-verify flag for TSC.
+                       Format: <string>
+                       [x86] reliable: mark tsc clocksource as reliable, this
+                       disables clocksource verification at runtime.
+                       Used to enable high-resolution timer mode on older
+                       hardware, and in virtualized environment.
+
        turbografx.map[2|3]=    [HW,JOY]
                        TurboGraFX parallel port interface
                        Format: