3ac7fe5a4a
We can see an ever repeating problem pattern with objects of any kind in the kernel: 1) freeing of active objects 2) reinitialization of active objects Both problems can be hard to debug because the crash happens at a point where we have no chance to decode the root cause anymore. One problem spot are kernel timers, where the detection of the problem often happens in interrupt context and usually causes the machine to panic. While working on a timer related bug report I had to hack specialized code into the timer subsystem to get a reasonable hint for the root cause. This debug hack was fine for temporary use, but far from a mergeable solution due to the intrusiveness into the timer code. The code further lacked the ability to detect and report the root cause instantly and keep the system operational. Keeping the system operational is important to get hold of the debug information without special debugging aids like serial consoles and special knowledge of the bug reporter. The problems described above are not restricted to timers, but timers tend to expose it usually in a full system crash. Other objects are less explosive, but the symptoms caused by such mistakes can be even harder to debug. Instead of creating specialized debugging code for the timer subsystem a generic infrastructure is created which allows developers to verify their code and provides an easy to enable debug facility for users in case of trouble. The debugobjects core code keeps track of operations on static and dynamic objects by inserting them into a hashed list and sanity checking them on object operations and provides additional checks whenever kernel memory is freed. The tracked object operations are: - initializing an object - adding an object to a subsystem list - deleting an object from a subsystem list Each operation is sanity checked before the operation is executed and the subsystem specific code can provide a fixup function which allows to prevent the damage of the operation. When the sanity check triggers a warning message and a stack trace is printed. The list of operations can be extended if the need arises. For now it's limited to the requirements of the first user (timers). The core code enqueues the objects into hash buckets. The hash index is generated from the address of the object to simplify the lookup for the check on kfree/vfree. Each bucket has it's own spinlock to avoid contention on a global lock. The debug code can be compiled in without being active. The runtime overhead is minimal and could be optimized by asm alternatives. A kernel command line option enables the debugging code. Thanks to Ingo Molnar for review, suggestions and cleanup patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Greg KH <greg@kroah.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2179 lines
68 KiB
Plaintext
2179 lines
68 KiB
Plaintext
Kernel Parameters
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~~~~~~~~~~~~~~~~~
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The following is a consolidated list of the kernel parameters as implemented
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(mostly) by the __setup() macro and sorted into English Dictionary order
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(defined as ignoring all punctuation and sorting digits before letters in a
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case insensitive manner), and with descriptions where known.
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Module parameters for loadable modules are specified only as the
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parameter name with optional '=' and value as appropriate, such as:
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modprobe usbcore blinkenlights=1
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Module parameters for modules that are built into the kernel image
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are specified on the kernel command line with the module name plus
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'.' plus parameter name, with '=' and value if appropriate, such as:
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usbcore.blinkenlights=1
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This document may not be entirely up to date and comprehensive. The command
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"modinfo -p ${modulename}" shows a current list of all parameters of a loadable
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module. Loadable modules, after being loaded into the running kernel, also
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reveal their parameters in /sys/module/${modulename}/parameters/. Some of these
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parameters may be changed at runtime by the command
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"echo -n ${value} > /sys/module/${modulename}/parameters/${parm}".
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The parameters listed below are only valid if certain kernel build options were
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enabled and if respective hardware is present. The text in square brackets at
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the beginning of each description states the restrictions within which a
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parameter is applicable:
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ACPI ACPI support is enabled.
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AGP AGP (Accelerated Graphics Port) is enabled.
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ALSA ALSA sound support is enabled.
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APIC APIC support is enabled.
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APM Advanced Power Management support is enabled.
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AVR32 AVR32 architecture is enabled.
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AX25 Appropriate AX.25 support is enabled.
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BLACKFIN Blackfin architecture is enabled.
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DRM Direct Rendering Management support is enabled.
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EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
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EFI EFI Partitioning (GPT) is enabled
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EIDE EIDE/ATAPI support is enabled.
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FB The frame buffer device is enabled.
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HW Appropriate hardware is enabled.
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IA-64 IA-64 architecture is enabled.
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IOSCHED More than one I/O scheduler is enabled.
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IP_PNP IP DHCP, BOOTP, or RARP is enabled.
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ISAPNP ISA PnP code is enabled.
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ISDN Appropriate ISDN support is enabled.
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JOY Appropriate joystick support is enabled.
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LIBATA Libata driver is enabled
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LP Printer support is enabled.
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LOOP Loopback device support is enabled.
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M68k M68k architecture is enabled.
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These options have more detailed description inside of
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Documentation/m68k/kernel-options.txt.
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MCA MCA bus support is enabled.
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MDA MDA console support is enabled.
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MOUSE Appropriate mouse support is enabled.
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MSI Message Signaled Interrupts (PCI).
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MTD MTD (Memory Technology Device) support is enabled.
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NET Appropriate network support is enabled.
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NUMA NUMA support is enabled.
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GENERIC_TIME The generic timeofday code is enabled.
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NFS Appropriate NFS support is enabled.
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OSS OSS sound support is enabled.
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PV_OPS A paravirtualized kernel is enabled.
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PARIDE The ParIDE (parallel port IDE) subsystem is enabled.
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PARISC The PA-RISC architecture is enabled.
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PCI PCI bus support is enabled.
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PCIE PCI Express support is enabled.
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PCMCIA The PCMCIA subsystem is enabled.
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PNP Plug & Play support is enabled.
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PPC PowerPC architecture is enabled.
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PPT Parallel port support is enabled.
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PS2 Appropriate PS/2 support is enabled.
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RAM RAM disk support is enabled.
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ROOTPLUG The example Root Plug LSM is enabled.
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S390 S390 architecture is enabled.
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SCSI Appropriate SCSI support is enabled.
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A lot of drivers has their options described inside of
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Documentation/scsi/.
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SECURITY Different security models are enabled.
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SELINUX SELinux support is enabled.
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SERIAL Serial support is enabled.
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SH SuperH architecture is enabled.
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SMP The kernel is an SMP kernel.
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SPARC Sparc architecture is enabled.
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SWSUSP Software suspend is enabled.
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TS Appropriate touchscreen support is enabled.
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USB USB support is enabled.
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USBHID USB Human Interface Device support is enabled.
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V4L Video For Linux support is enabled.
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VGA The VGA console has been enabled.
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VT Virtual terminal support is enabled.
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WDT Watchdog support is enabled.
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XT IBM PC/XT MFM hard disk support is enabled.
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X86-32 X86-32, aka i386 architecture is enabled.
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X86-64 X86-64 architecture is enabled.
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More X86-64 boot options can be found in
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Documentation/x86_64/boot-options.txt .
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In addition, the following text indicates that the option:
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BUGS= Relates to possible processor bugs on the said processor.
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KNL Is a kernel start-up parameter.
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BOOT Is a boot loader parameter.
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Parameters denoted with BOOT are actually interpreted by the boot
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loader, and have no meaning to the kernel directly.
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Do not modify the syntax of boot loader parameters without extreme
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need or coordination with <Documentation/i386/boot.txt>.
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There are also arch-specific kernel-parameters not documented here.
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See for example <Documentation/x86_64/boot-options.txt>.
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Note that ALL kernel parameters listed below are CASE SENSITIVE, and that
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a trailing = on the name of any parameter states that that parameter will
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be entered as an environment variable, whereas its absence indicates that
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it will appear as a kernel argument readable via /proc/cmdline by programs
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running once the system is up.
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The number of kernel parameters is not limited, but the length of the
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complete command line (parameters including spaces etc.) is limited to
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a fixed number of characters. This limit depends on the architecture
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and is between 256 and 4096 characters. It is defined in the file
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./include/asm/setup.h as COMMAND_LINE_SIZE.
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acpi= [HW,ACPI,X86-64,i386]
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Advanced Configuration and Power Interface
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Format: { force | off | ht | strict | noirq }
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force -- enable ACPI if default was off
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off -- disable ACPI if default was on
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noirq -- do not use ACPI for IRQ routing
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ht -- run only enough ACPI to enable Hyper Threading
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strict -- Be less tolerant of platforms that are not
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strictly ACPI specification compliant.
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See also Documentation/power/pm.txt, pci=noacpi
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acpi_apic_instance= [ACPI, IOAPIC]
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Format: <int>
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2: use 2nd APIC table, if available
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1,0: use 1st APIC table
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default: 0
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acpi_sleep= [HW,ACPI] Sleep options
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Format: { s3_bios, s3_mode, s3_beep }
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See Documentation/power/video.txt for s3_bios and s3_mode.
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s3_beep is for debugging; it makes the PC's speaker beep
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as soon as the kernel's real-mode entry point is called.
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acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
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Format: { level | edge | high | low }
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acpi_irq_balance [HW,ACPI]
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ACPI will balance active IRQs
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default in APIC mode
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acpi_irq_nobalance [HW,ACPI]
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ACPI will not move active IRQs (default)
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default in PIC mode
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acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for
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use by PCI
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Format: <irq>,<irq>...
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acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA
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Format: <irq>,<irq>...
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acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT
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acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS
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Format: To spoof as Windows 98: ="Microsoft Windows"
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acpi_osi= [HW,ACPI] Modify list of supported OS interface strings
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acpi_osi="string1" # add string1 -- only one string
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acpi_osi="!string2" # remove built-in string2
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acpi_osi= # disable all strings
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acpi_serialize [HW,ACPI] force serialization of AML methods
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acpi_skip_timer_override [HW,ACPI]
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Recognize and ignore IRQ0/pin2 Interrupt Override.
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For broken nForce2 BIOS resulting in XT-PIC timer.
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acpi_use_timer_override [HW,ACPI}
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Use timer override. For some broken Nvidia NF5 boards
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that require a timer override, but don't have
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HPET
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acpi.debug_layer= [HW,ACPI]
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Format: <int>
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Each bit of the <int> indicates an ACPI debug layer,
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1: enable, 0: disable. It is useful for boot time
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debugging. After system has booted up, it can be set
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via /sys/module/acpi/parameters/debug_layer.
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CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
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Available bits (add the numbers together) to enable debug output
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for specific parts of the ACPI subsystem:
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0x01 utilities 0x02 hardware 0x04 events 0x08 tables
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0x10 namespace 0x20 parser 0x40 dispatcher
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0x80 executer 0x100 resources 0x200 acpica debugger
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0x400 os services 0x800 acpica disassembler.
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The number can be in decimal or prefixed with 0x in hex.
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Warning: Many of these options can produce a lot of
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output and make your system unusable. Be very careful.
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acpi.debug_level= [HW,ACPI]
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Format: <int>
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Each bit of the <int> indicates an ACPI debug level,
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1: enable, 0: disable. It is useful for boot time
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debugging. After system has booted up, it can be set
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via /sys/module/acpi/parameters/debug_level.
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CONFIG_ACPI_DEBUG must be enabled for this to produce any output.
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Available bits (add the numbers together) to enable different
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debug output levels of the ACPI subsystem:
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0x01 error 0x02 warn 0x04 init 0x08 debug object
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0x10 info 0x20 init names 0x40 parse 0x80 load
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0x100 dispatch 0x200 execute 0x400 names 0x800 operation region
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0x1000 bfield 0x2000 tables 0x4000 values 0x8000 objects
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0x10000 resources 0x20000 user requests 0x40000 package.
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The number can be in decimal or prefixed with 0x in hex.
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Warning: Many of these options can produce a lot of
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output and make your system unusable. Be very careful.
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acpi_pm_good [X86-32,X86-64]
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Override the pmtimer bug detection: force the kernel
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to assume that this machine's pmtimer latches its value
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and always returns good values.
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agp= [AGP]
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{ off | try_unsupported }
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off: disable AGP support
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try_unsupported: try to drive unsupported chipsets
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(may crash computer or cause data corruption)
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enable_timer_pin_1 [i386,x86-64]
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Enable PIN 1 of APIC timer
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Can be useful to work around chipset bugs
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(in particular on some ATI chipsets).
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The kernel tries to set a reasonable default.
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disable_timer_pin_1 [i386,x86-64]
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Disable PIN 1 of APIC timer
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Can be useful to work around chipset bugs.
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ad1848= [HW,OSS]
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Format: <io>,<irq>,<dma>,<dma2>,<type>
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advansys= [HW,SCSI]
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See header of drivers/scsi/advansys.c.
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advwdt= [HW,WDT] Advantech WDT
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Format: <iostart>,<iostop>
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aedsp16= [HW,OSS] Audio Excel DSP 16
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Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
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See also header of sound/oss/aedsp16.c.
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aha152x= [HW,SCSI]
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See Documentation/scsi/aha152x.txt.
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aha1542= [HW,SCSI]
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Format: <portbase>[,<buson>,<busoff>[,<dmaspeed>]]
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aic7xxx= [HW,SCSI]
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See Documentation/scsi/aic7xxx.txt.
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aic79xx= [HW,SCSI]
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See Documentation/scsi/aic79xx.txt.
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amijoy.map= [HW,JOY] Amiga joystick support
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Map of devices attached to JOY0DAT and JOY1DAT
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Format: <a>,<b>
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See also Documentation/kernel/input/joystick.txt
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analog.map= [HW,JOY] Analog joystick and gamepad support
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Specifies type or capabilities of an analog joystick
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connected to one of 16 gameports
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Format: <type1>,<type2>,..<type16>
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apc= [HW,SPARC]
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Power management functions (SPARCstation-4/5 + deriv.)
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Format: noidle
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Disable APC CPU standby support. SPARCstation-Fox does
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not play well with APC CPU idle - disable it if you have
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APC and your system crashes randomly.
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apic= [APIC,i386] Advanced Programmable Interrupt Controller
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Change the output verbosity whilst booting
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Format: { quiet (default) | verbose | debug }
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Change the amount of debugging information output
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when initialising the APIC and IO-APIC components.
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apm= [APM] Advanced Power Management
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See header of arch/i386/kernel/apm.c.
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arcrimi= [HW,NET] ARCnet - "RIM I" (entirely mem-mapped) cards
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Format: <io>,<irq>,<nodeID>
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ataflop= [HW,M68k]
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atarimouse= [HW,MOUSE] Atari Mouse
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atascsi= [HW,SCSI] Atari SCSI
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atkbd.extra= [HW] Enable extra LEDs and keys on IBM RapidAccess,
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EzKey and similar keyboards
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atkbd.reset= [HW] Reset keyboard during initialization
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atkbd.set= [HW] Select keyboard code set
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Format: <int> (2 = AT (default), 3 = PS/2)
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atkbd.scroll= [HW] Enable scroll wheel on MS Office and similar
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keyboards
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atkbd.softraw= [HW] Choose between synthetic and real raw mode
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Format: <bool> (0 = real, 1 = synthetic (default))
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atkbd.softrepeat= [HW]
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Use software keyboard repeat
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autotest [IA64]
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baycom_epp= [HW,AX25]
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Format: <io>,<mode>
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baycom_par= [HW,AX25] BayCom Parallel Port AX.25 Modem
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Format: <io>,<mode>
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See header of drivers/net/hamradio/baycom_par.c.
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baycom_ser_fdx= [HW,AX25]
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BayCom Serial Port AX.25 Modem (Full Duplex Mode)
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Format: <io>,<irq>,<mode>[,<baud>]
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See header of drivers/net/hamradio/baycom_ser_fdx.c.
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baycom_ser_hdx= [HW,AX25]
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BayCom Serial Port AX.25 Modem (Half Duplex Mode)
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Format: <io>,<irq>,<mode>
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See header of drivers/net/hamradio/baycom_ser_hdx.c.
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boot_delay= Milliseconds to delay each printk during boot.
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Values larger than 10 seconds (10000) are changed to
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no delay (0).
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Format: integer
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bttv.card= [HW,V4L] bttv (bt848 + bt878 based grabber cards)
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bttv.radio= Most important insmod options are available as
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kernel args too.
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bttv.pll= See Documentation/video4linux/bttv/Insmod-options
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bttv.tuner= and Documentation/video4linux/bttv/CARDLIST
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BusLogic= [HW,SCSI]
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See drivers/scsi/BusLogic.c, comment before function
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BusLogic_ParseDriverOptions().
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c101= [NET] Moxa C101 synchronous serial card
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cachesize= [BUGS=X86-32] Override level 2 CPU cache size detection.
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Sometimes CPU hardware bugs make them report the cache
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size incorrectly. The kernel will attempt work arounds
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to fix known problems, but for some CPUs it is not
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possible to determine what the correct size should be.
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This option provides an override for these situations.
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security= [SECURITY] Choose a security module to enable at boot.
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If this boot parameter is not specified, only the first
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security module asking for security registration will be
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loaded. An invalid security module name will be treated
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as if no module has been chosen.
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capability.disable=
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[SECURITY] Disable capabilities. This would normally
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be used only if an alternative security model is to be
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configured. Potentially dangerous and should only be
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used if you are entirely sure of the consequences.
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ccw_timeout_log [S390]
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See Documentation/s390/CommonIO for details.
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cgroup_disable= [KNL] Disable a particular controller
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Format: {name of the controller(s) to disable}
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{Currently supported controllers - "memory"}
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checkreqprot [SELINUX] Set initial checkreqprot flag value.
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Format: { "0" | "1" }
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See security/selinux/Kconfig help text.
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0 -- check protection applied by kernel (includes
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any implied execute protection).
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1 -- check protection requested by application.
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Default value is set via a kernel config option.
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Value can be changed at runtime via
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/selinux/checkreqprot.
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cio_ignore= [S390]
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See Documentation/s390/CommonIO for details.
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cio_msg= [S390]
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See Documentation/s390/CommonIO for details.
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clock= [BUGS=X86-32, HW] gettimeofday clocksource override.
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[Deprecated]
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Forces specified clocksource (if available) to be used
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when calculating gettimeofday(). If specified
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clocksource is not available, it defaults to PIT.
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Format: { pit | tsc | cyclone | pmtmr }
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clocksource= [GENERIC_TIME] Override the default clocksource
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Format: <string>
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Override the default clocksource and use the clocksource
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with the name specified.
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Some clocksource names to choose from, depending on
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the platform:
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[all] jiffies (this is the base, fallback clocksource)
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[ACPI] acpi_pm
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[ARM] imx_timer1,OSTS,netx_timer,mpu_timer2,
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pxa_timer,timer3,32k_counter,timer0_1
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[AVR32] avr32
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[X86-32] pit,hpet,tsc,vmi-timer;
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scx200_hrt on Geode; cyclone on IBM x440
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[MIPS] MIPS
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[PARISC] cr16
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[S390] tod
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[SH] SuperH
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[SPARC64] tick
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[X86-64] hpet,tsc
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clearcpuid=BITNUM [X86]
|
|
Disable CPUID feature X for the kernel. See
|
|
include/asm-x86/cpufeature.h for the valid bit numbers.
|
|
Note the Linux specific bits are not necessarily
|
|
stable over kernel options, but the vendor specific
|
|
ones should be.
|
|
Also note that user programs calling CPUID directly
|
|
or using the feature without checking anything
|
|
will still see it. This just prevents it from
|
|
being used by the kernel or shown in /proc/cpuinfo.
|
|
Also note the kernel might malfunction if you disable
|
|
some critical bits.
|
|
|
|
code_bytes [IA32/X86_64] 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= [X86-32,HPET] option to control HPET usage
|
|
Format: { enable (default) | disable | force }
|
|
disable: disable HPET and use PIT instead
|
|
force: allow force enabled of undocumented chips (ICH4,
|
|
VIA, nVidia)
|
|
|
|
com20020= [HW,NET] ARCnet - COM20020 chipset
|
|
Format:
|
|
<io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]]
|
|
|
|
com90io= [HW,NET] ARCnet - COM90xx chipset (IO-mapped buffers)
|
|
Format: <io>[,<irq>]
|
|
|
|
com90xx= [HW,NET]
|
|
ARCnet - COM90xx chipset (memory-mapped buffers)
|
|
Format: <io>[,<irq>[,<memstart>]]
|
|
|
|
condev= [HW,S390] console device
|
|
conmode=
|
|
|
|
console= [KNL] Output console device and options.
|
|
|
|
tty<n> Use the virtual console device <n>.
|
|
|
|
ttyS<n>[,options]
|
|
ttyUSB0[,options]
|
|
Use the specified serial port. The options are of
|
|
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 Documentation/serial-console.txt for more
|
|
information. See
|
|
Documentation/networking/netconsole.txt for an
|
|
alternative.
|
|
|
|
uart[8250],io,<addr>[,options]
|
|
uart[8250],mmio,<addr>[,options]
|
|
Start an early, polled-mode console on the 8250/16550
|
|
UART at the specified I/O port or MMIO address,
|
|
switching to the matching ttyS device later. The
|
|
options are the same as for ttyS, above.
|
|
|
|
If the device connected to the port is not a TTY but a braille
|
|
device, prepend "brl," before the device type, for instance
|
|
console=brl,ttyS0
|
|
For now, only VisioBraille is supported.
|
|
|
|
earlycon= [KNL] Output early console device and options.
|
|
uart[8250],io,<addr>[,options]
|
|
uart[8250],mmio,<addr>[,options]
|
|
Start an early, polled-mode console on the 8250/16550
|
|
UART at the specified I/O port or MMIO address.
|
|
The options are the same as for ttyS, above.
|
|
|
|
no_console_suspend
|
|
[HW] Never suspend the console
|
|
Disable suspending of consoles during suspend and
|
|
hibernate operations. Once disabled, debugging
|
|
messages can reach various consoles while the rest
|
|
of the system is being put to sleep (ie, while
|
|
debugging driver suspend/resume hooks). This may
|
|
not work reliably with all consoles, but is known
|
|
to work with serial and VGA consoles.
|
|
|
|
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
|
|
Format:
|
|
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
|
|
|
|
crashkernel=nn[KMG]@ss[KMG]
|
|
[KNL] Reserve a chunk of physical memory to
|
|
hold a kernel to switch to with kexec on panic.
|
|
|
|
crashkernel=range1:size1[,range2:size2,...][@offset]
|
|
[KNL] Same as above, but depends on the memory
|
|
in the running system. The syntax of range is
|
|
start-[end] where start and end are both
|
|
a memory unit (amount[KMG]). See also
|
|
Documentation/kdump/kdump.txt for a example.
|
|
|
|
cs4232= [HW,OSS]
|
|
Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq>
|
|
|
|
cs89x0_dma= [HW,NET]
|
|
Format: <dma>
|
|
|
|
cs89x0_media= [HW,NET]
|
|
Format: { rj45 | aui | bnc }
|
|
|
|
dasd= [HW,NET]
|
|
See header of drivers/s390/block/dasd_devmap.c.
|
|
|
|
db9.dev[2|3]= [HW,JOY] Multisystem joystick support via parallel port
|
|
(one device per port)
|
|
Format: <port#>,<type>
|
|
See also Documentation/input/joystick-parport.txt
|
|
|
|
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.
|
|
|
|
debug_objects [KNL] Enable object debugging
|
|
|
|
decnet.addr= [HW,NET]
|
|
Format: <area>[,<node>]
|
|
See also Documentation/networking/decnet.txt.
|
|
|
|
vt.default_blu= [VT]
|
|
Format: <blue0>,<blue1>,<blue2>,...,<blue15>
|
|
Change the default blue palette of the console.
|
|
This is a 16-member array composed of values
|
|
ranging from 0-255.
|
|
|
|
vt.default_grn= [VT]
|
|
Format: <green0>,<green1>,<green2>,...,<green15>
|
|
Change the default green palette of the console.
|
|
This is a 16-member array composed of values
|
|
ranging from 0-255.
|
|
|
|
vt.default_red= [VT]
|
|
Format: <red0>,<red1>,<red2>,...,<red15>
|
|
Change the default red palette of the console.
|
|
This is a 16-member array composed of values
|
|
ranging from 0-255.
|
|
|
|
vt.default_utf8=
|
|
[VT]
|
|
Format=<0|1>
|
|
Set system-wide default UTF-8 mode for all tty's.
|
|
Default is 1, i.e. UTF-8 mode is enabled for all
|
|
newly opened terminals.
|
|
|
|
dhash_entries= [KNL]
|
|
Set number of hash buckets for dentry cache.
|
|
|
|
digi= [HW,SERIAL]
|
|
IO parameters + enable/disable command.
|
|
|
|
digiepca= [HW,SERIAL]
|
|
See drivers/char/README.epca and
|
|
Documentation/digiepca.txt.
|
|
|
|
disable_mtrr_trim [X86, Intel and AMD only]
|
|
By default the kernel will trim any uncacheable
|
|
memory out of your available memory pool based on
|
|
MTRR settings. This parameter disables that behavior,
|
|
possibly causing your machine to run very slowly.
|
|
|
|
dmasound= [HW,OSS] Sound subsystem buffers
|
|
|
|
dscc4.setup= [NET]
|
|
|
|
dtc3181e= [HW,SCSI]
|
|
|
|
earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
|
|
earlyprintk=vga
|
|
earlyprintk=serial[,ttySn[,baudrate]]
|
|
|
|
Append ",keep" to not disable it when the real console
|
|
takes over.
|
|
|
|
Only vga or serial at a time, not both.
|
|
|
|
Currently only ttyS0 and ttyS1 are supported.
|
|
|
|
Interaction with the standard serial driver is not
|
|
very good.
|
|
|
|
The VGA output is eventually overwritten by the real
|
|
console.
|
|
|
|
eata= [HW,SCSI]
|
|
|
|
edd= [EDD]
|
|
Format: {"off" | "on" | "skip[mbr]"}
|
|
|
|
eisa_irq_edge= [PARISC,HW]
|
|
See header of drivers/parisc/eisa.c.
|
|
|
|
elanfreq= [X86-32]
|
|
See comment before function elanfreq_setup() in
|
|
arch/i386/kernel/cpu/cpufreq/elanfreq.c.
|
|
|
|
elevator= [IOSCHED]
|
|
Format: {"anticipatory" | "cfq" | "deadline" | "noop"}
|
|
See Documentation/block/as-iosched.txt and
|
|
Documentation/block/deadline-iosched.txt for details.
|
|
|
|
elfcorehdr= [X86-32, X86_64]
|
|
Specifies physical address of start of kernel core
|
|
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"}
|
|
See security/selinux/Kconfig help text.
|
|
0 -- permissive (log only, no denials).
|
|
1 -- enforcing (deny and log).
|
|
Default value is 0.
|
|
Value can be changed at runtime via /selinux/enforce.
|
|
|
|
es1371= [HW,OSS]
|
|
Format: <spdif>,[<nomix>,[<amplifier>]]
|
|
See also header of sound/oss/es1371.c.
|
|
|
|
ether= [HW,NET] Ethernet cards parameters
|
|
This option is obsoleted by the "netdev=" option, which
|
|
has equivalent usage. See its documentation for details.
|
|
|
|
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.
|
|
|
|
fdomain= [HW,SCSI]
|
|
See header of drivers/scsi/fdomain.c.
|
|
|
|
floppy= [HW]
|
|
See Documentation/floppy.txt.
|
|
|
|
gamecon.map[2|3]=
|
|
[HW,JOY] Multisystem joystick and NES/SNES/PSX pad
|
|
support via parallel port (up to 5 devices per port)
|
|
Format: <port#>,<pad1>,<pad2>,<pad3>,<pad4>,<pad5>
|
|
See also Documentation/input/joystick-parport.txt
|
|
|
|
gamma= [HW,DRM]
|
|
|
|
gart_fix_e820= [X86_64] disable the fix e820 for K8 GART
|
|
Format: off | on
|
|
default: on
|
|
|
|
gdth= [HW,SCSI]
|
|
See header of drivers/scsi/gdth.c.
|
|
|
|
gpt [EFI] Forces disk with valid GPT signature but
|
|
invalid Protective MBR to be treated as GPT.
|
|
|
|
gvp11= [HW,SCSI]
|
|
|
|
hashdist= [KNL,NUMA] Large hashes allocated during boot
|
|
are distributed across NUMA nodes. Defaults on
|
|
for IA-64, off otherwise.
|
|
Format: 0 | 1 (for off | on)
|
|
|
|
hcl= [IA-64] SGI's Hardware Graph compatibility layer
|
|
|
|
hd= [EIDE] (E)IDE hard drive subsystem geometry
|
|
Format: <cyl>,<head>,<sect>
|
|
|
|
hd?= [HW] (E)IDE subsystem
|
|
hd?lun= See Documentation/ide/ide.txt.
|
|
|
|
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
|
|
size of <nn>. This works even on boxes that have no
|
|
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,X86-32,IA-64] Maximal number of HugeTLB pages.
|
|
hugepagesz= [HW,IA-64,PPC] The size of the HugeTLB pages.
|
|
|
|
i8042.direct [HW] Put keyboard port into non-translated mode
|
|
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
|
|
i8042.noloop [HW] Disable the AUX Loopback command while probing
|
|
for the AUX port
|
|
i8042.nomux [HW] Don't check presence of an active multiplexing
|
|
controller
|
|
i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX
|
|
controllers
|
|
i8042.panicblink=
|
|
[HW] Frequency with which keyboard LEDs should blink
|
|
when kernel panics (default is 0.5 sec)
|
|
i8042.reset [HW] Reset the controller during init and cleanup
|
|
i8042.unlock [HW] Unlock (ignore) the keylock
|
|
|
|
i810= [HW,DRM]
|
|
|
|
i8k.ignore_dmi [HW] Continue probing hardware even if DMI data
|
|
indicates that the driver is running on unsupported
|
|
hardware.
|
|
i8k.force [HW] Activate i8k driver even if SMM BIOS signature
|
|
does not match list of supported models.
|
|
i8k.power_status
|
|
[HW] Report power status in /proc/i8k
|
|
(disabled by default)
|
|
i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN
|
|
capability is set.
|
|
|
|
ibmmcascsi= [HW,MCA,SCSI] IBM MicroChannel SCSI adapter
|
|
See Documentation/mca.txt.
|
|
|
|
icn= [HW,ISDN]
|
|
Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]]
|
|
|
|
ide= [HW] (E)IDE subsystem
|
|
Format: ide=nodma or ide=doubler
|
|
See Documentation/ide/ide.txt.
|
|
|
|
idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed
|
|
See Documentation/ide/ide.txt.
|
|
|
|
idle= [X86]
|
|
Format: idle=poll or idle=mwait
|
|
Poll forces a polling idle loop that can slightly improves the performance
|
|
of waking up a idle CPU, but will use a lot of power and make the system
|
|
run hot. Not recommended.
|
|
idle=mwait. On systems which support MONITOR/MWAIT but the kernel chose
|
|
to not use it because it doesn't save as much power as a normal idle
|
|
loop use the MONITOR/MWAIT idle loop anyways. Performance should be the same
|
|
as idle=poll.
|
|
|
|
ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem
|
|
Claim all unknown PCI IDE storage controllers.
|
|
|
|
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.
|
|
|
|
in2000= [HW,SCSI]
|
|
See header of drivers/scsi/in2000.c.
|
|
|
|
init= [KNL]
|
|
Format: <full_path>
|
|
Run specified binary instead of /sbin/init as init
|
|
process.
|
|
|
|
initcall_debug [KNL] Trace initcalls as they are executed. Useful
|
|
for working out where the kernel is dying during
|
|
startup.
|
|
|
|
initrd= [BOOT] Specify the location of the initial ramdisk
|
|
|
|
inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver
|
|
Format: <irq>
|
|
|
|
inttest= [IA64]
|
|
|
|
iommu= [x86]
|
|
off
|
|
force
|
|
noforce
|
|
biomerge
|
|
panic
|
|
nopanic
|
|
merge
|
|
nomerge
|
|
forcesac
|
|
soft
|
|
|
|
|
|
intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option
|
|
off
|
|
Disable intel iommu driver.
|
|
igfx_off [Default Off]
|
|
By default, gfx is mapped as normal device. If a gfx
|
|
device has a dedicated DMAR unit, the DMAR unit is
|
|
bypassed by not enabling DMAR with this option. In
|
|
this case, gfx device will use physical address for
|
|
DMA.
|
|
forcedac [x86_64]
|
|
With this option iommu will not optimize to look
|
|
for io virtual address below 32 bit forcing dual
|
|
address cycle on pci bus for cards supporting greater
|
|
than 32 bit addressing. The default is to look
|
|
for translation below 32 bit and if not available
|
|
then look in the higher range.
|
|
strict [Default Off]
|
|
With this option on every unmap_single operation will
|
|
result in a hardware IOTLB flush operation as opposed
|
|
to batching them for performance.
|
|
|
|
io_delay= [X86-32,X86-64] I/O delay method
|
|
0x80
|
|
Standard port 0x80 based delay
|
|
0xed
|
|
Alternate port 0xed based delay (needed on some systems)
|
|
udelay
|
|
Simple two microseconds delay
|
|
none
|
|
No delay
|
|
|
|
io7= [HW] IO7 for Marvel based alpha systems
|
|
See comment before marvel_specify_io7 in
|
|
arch/alpha/kernel/core_marvel.c.
|
|
|
|
ip= [IP_PNP]
|
|
See Documentation/filesystems/nfsroot.txt.
|
|
|
|
ip2= [HW] Set IO/IRQ pairs for up to 4 IntelliPort boards
|
|
See comment before ip2_setup() in
|
|
drivers/char/ip2/ip2base.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
|
|
firmware running.
|
|
|
|
irqpoll [HW]
|
|
When an interrupt is not handled search all handlers
|
|
for it. Also check all handlers each timer
|
|
interrupt. Intended to get systems with badly broken
|
|
firmware running.
|
|
|
|
isapnp= [ISAPNP]
|
|
Format: <RDP>,<reset>,<pci_scan>,<verbosity>
|
|
|
|
isolcpus= [KNL,SMP] Isolate CPUs from the general scheduler.
|
|
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
|
|
an "isolated" CPU is via the CPU affinity syscalls.
|
|
<cpu number> begins at 0 and the maximum value is
|
|
"number of CPUs in system - 1".
|
|
|
|
This option is the preferred way to isolate CPUs. The
|
|
alternative -- manually setting the CPU mask of all
|
|
tasks in the system -- can cause problems and
|
|
suboptimal load balancer performance.
|
|
|
|
iucv= [HW,NET]
|
|
|
|
js= [HW,JOY] Analog joystick
|
|
See Documentation/input/joystick.txt.
|
|
|
|
kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
|
|
specifies the amount of memory usable by the kernel
|
|
for non-movable allocations. The requested amount is
|
|
spread evenly throughout all nodes in the system. The
|
|
remaining memory in each node is used for Movable
|
|
pages. In the event, a node is too small to have both
|
|
kernelcore and Movable pages, kernelcore pages will
|
|
take priority and other nodes will have a larger number
|
|
of kernelcore pages. The Movable zone is used for the
|
|
allocation of pages that may be reclaimed or moved
|
|
by the page migration subsystem. This means that
|
|
HugeTLB pages may not be allocated from this zone.
|
|
Note that allocations like PTEs-from-HighMem still
|
|
use the HighMem zone if it exists, and the Normal
|
|
zone if it does not.
|
|
|
|
movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
|
|
is similar to kernelcore except it specifies the
|
|
amount of memory used for migratable allocations.
|
|
If both kernelcore and movablecore is specified,
|
|
then kernelcore will be at *least* the specified
|
|
value but may be more. If movablecore on its own
|
|
is specified, the administrator must be careful
|
|
that the amount of memory usable for all allocations
|
|
is not too small.
|
|
|
|
keepinitrd [HW,ARM]
|
|
|
|
kstack=N [X86-32,X86-64] Print N words from the kernel stack
|
|
in oops dumps.
|
|
|
|
kgdboc= [HW] kgdb over consoles.
|
|
Requires a tty driver that supports console polling.
|
|
(only serial suported for now)
|
|
Format: <serial_device>[,baud]
|
|
|
|
l2cr= [PPC]
|
|
|
|
l3cr= [PPC]
|
|
|
|
lapic [X86-32,APIC] Enable the local APIC even if BIOS
|
|
disabled it.
|
|
|
|
lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer in
|
|
C2 power state.
|
|
|
|
libata.dma= [LIBATA] DMA control
|
|
libata.dma=0 Disable all PATA and SATA DMA
|
|
libata.dma=1 PATA and SATA Disk DMA only
|
|
libata.dma=2 ATAPI (CDROM) DMA only
|
|
libata.dma=4 Compact Flash DMA only
|
|
Combinations also work, so libata.dma=3 enables DMA
|
|
for disks and CDROMs, but not CFs.
|
|
|
|
libata.noacpi [LIBATA] Disables use of ACPI in libata suspend/resume
|
|
when set.
|
|
Format: <int>
|
|
|
|
libata.force= [LIBATA] Force configurations. The format is comma
|
|
separated list of "[ID:]VAL" where ID is
|
|
PORT[:DEVICE]. PORT and DEVICE are decimal numbers
|
|
matching port, link or device. Basically, it matches
|
|
the ATA ID string printed on console by libata. If
|
|
the whole ID part is omitted, the last PORT and DEVICE
|
|
values are used. If ID hasn't been specified yet, the
|
|
configuration applies to all ports, links and devices.
|
|
|
|
If only DEVICE is omitted, the parameter applies to
|
|
the port and all links and devices behind it. DEVICE
|
|
number of 0 either selects the first device or the
|
|
first fan-out link behind PMP device. It does not
|
|
select the host link. DEVICE number of 15 selects the
|
|
host link and device attached to it.
|
|
|
|
The VAL specifies the configuration to force. As long
|
|
as there's no ambiguity shortcut notation is allowed.
|
|
For example, both 1.5 and 1.5G would work for 1.5Gbps.
|
|
The following configurations can be forced.
|
|
|
|
* Cable type: 40c, 80c, short40c, unk, ign or sata.
|
|
Any ID with matching PORT is used.
|
|
|
|
* SATA link speed limit: 1.5Gbps or 3.0Gbps.
|
|
|
|
* Transfer mode: pio[0-7], mwdma[0-4] and udma[0-7].
|
|
udma[/][16,25,33,44,66,100,133] notation is also
|
|
allowed.
|
|
|
|
* [no]ncq: Turn on or off NCQ.
|
|
|
|
If there are multiple matching configurations changing
|
|
the same attribute, the last one is used.
|
|
|
|
load_ramdisk= [RAM] List of ramdisks to load from floppy
|
|
See Documentation/ramdisk.txt.
|
|
|
|
lockd.nlm_grace_period=P [NFS] Assign grace period.
|
|
Format: <integer>
|
|
|
|
lockd.nlm_tcpport=N [NFS] Assign TCP port.
|
|
Format: <integer>
|
|
|
|
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>
|
|
|
|
loglevel= All Kernel Messages with a loglevel smaller than the
|
|
console loglevel will be printed to the console. It can
|
|
also be changed with klogd or other programs. The
|
|
loglevels are defined as follows:
|
|
|
|
0 (KERN_EMERG) system is unusable
|
|
1 (KERN_ALERT) action must be taken immediately
|
|
2 (KERN_CRIT) critical conditions
|
|
3 (KERN_ERR) error conditions
|
|
4 (KERN_WARNING) warning conditions
|
|
5 (KERN_NOTICE) normal but significant condition
|
|
6 (KERN_INFO) informational
|
|
7 (KERN_DEBUG) debug-level messages
|
|
|
|
log_buf_len=n Sets the size of the printk ring buffer, in bytes.
|
|
Format: { n | nk | nM }
|
|
n must be a power of two. The default size
|
|
is set in the kernel config file.
|
|
|
|
logo.nologo [FB] Disables display of the built-in Linux logo.
|
|
This may be used to provide more screen space for
|
|
kernel log messages and is useful when debugging
|
|
kernel boot problems.
|
|
|
|
lp=0 [LP] Specify parallel ports to use, e.g,
|
|
lp=port[,port...] lp=none,parport0 (lp0 not configured, lp1 uses
|
|
lp=reset first parallel port). 'lp=0' disables the
|
|
lp=auto printer driver. 'lp=reset' (which can be
|
|
specified in addition to the ports) causes
|
|
attached printers to be reset. Using
|
|
lp=port1,port2,... specifies the parallel ports
|
|
to associate lp devices with, starting with
|
|
lp0. A port specification may be 'none' to skip
|
|
that lp device, or a parport name such as
|
|
'parport0'. Specifying 'lp=auto' instead of a
|
|
port specification list means that device IDs
|
|
from each port should be examined, to see if
|
|
an IEEE 1284-compliant printer is attached; if
|
|
so, the driver will manage that printer.
|
|
See also header of drivers/char/lp.c.
|
|
|
|
lpj=n [KNL]
|
|
Sets loops_per_jiffy to given constant, thus avoiding
|
|
time-consuming boot-time autodetection (up to 250 ms per
|
|
CPU). 0 enables autodetection (default). To determine
|
|
the correct value for your kernel, boot with normal
|
|
autodetection and see what value is printed. Note that
|
|
on SMP systems the preset will be applied to all CPUs,
|
|
which is likely to cause problems if your CPUs need
|
|
significantly divergent settings. An incorrect value
|
|
will cause delays in the kernel to be wrong, leading to
|
|
unpredictable I/O errors and other breakage. Although
|
|
unlikely, in the extreme case this might damage your
|
|
hardware.
|
|
|
|
ltpc= [NET]
|
|
Format: <io>,<irq>,<dma>
|
|
|
|
mac5380= [HW,SCSI] Format:
|
|
<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
|
|
|
|
mac53c9x= [HW,SCSI] Format:
|
|
<num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
|
|
|
|
machvec= [IA64] Force the use of a particular machine-vector
|
|
(machvec) in a generic kernel.
|
|
Example: machvec=hpzx1_swiotlb
|
|
|
|
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. maxcpus=n : n >= 0 limits the
|
|
kernel to using 'n' processors. n=0 is a special case,
|
|
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_luns= [SCSI] Maximum number of LUNs to probe.
|
|
Should be between 1 and 2^32-1.
|
|
|
|
max_report_luns=
|
|
[SCSI] Maximum number of LUNs received.
|
|
Should be between 1 and 16384.
|
|
|
|
mcatest= [IA-64]
|
|
|
|
mce [X86-32] Machine Check Exception
|
|
|
|
mce=option [X86-64] See Documentation/x86_64/boot-options.txt
|
|
|
|
md= [HW] RAID subsystems devices and level
|
|
See Documentation/md.txt.
|
|
|
|
mdacon= [MDA]
|
|
Format: <first>,<last>
|
|
Specifies range of consoles to be captured by the MDA.
|
|
|
|
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
|
|
Amount of memory to be used when the kernel is not able
|
|
to see the whole system memory or for test.
|
|
[X86-32] Use together with memmap= to avoid physical
|
|
address space collisions. Without memmap= PCI devices
|
|
could be placed at addresses belonging to unused RAM.
|
|
|
|
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
|
|
memory.
|
|
|
|
memmap=exactmap [KNL,X86-32,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
|
|
option description.
|
|
|
|
memmap=nn[KMG]@ss[KMG]
|
|
[KNL] Force usage of a specific region of memory
|
|
Region of memory to be used, from ss to ss+nn.
|
|
|
|
memmap=nn[KMG]#ss[KMG]
|
|
[KNL,ACPI] Mark specific memory as ACPI data.
|
|
Region of memory to be used, from ss to ss+nn.
|
|
|
|
memmap=nn[KMG]$ss[KMG]
|
|
[KNL,ACPI] Mark specific memory as reserved.
|
|
Region of memory to be used, from ss to ss+nn.
|
|
Example: Exclude memory from 0x18690000-0x1869ffff
|
|
memmap=64K$0x18690000
|
|
or
|
|
memmap=0x10000$0x18690000
|
|
|
|
memtest= [KNL,X86_64] Enable memtest
|
|
Format: <integer>
|
|
range: 0,4 : pattern number
|
|
default : 0 <disable>
|
|
|
|
meye.*= [HW] Set MotionEye Camera parameters
|
|
See Documentation/video4linux/meye.txt.
|
|
|
|
mfgpt_irq= [IA-32] Specify the IRQ to use for the
|
|
Multi-Function General Purpose Timers on AMD Geode
|
|
platforms.
|
|
|
|
mfgptfix [X86-32] Fix MFGPT timers on AMD Geode platforms when
|
|
the BIOS has incorrectly applied a workaround. TinyBIOS
|
|
version 0.98 is known to be affected, 0.99 fixes the
|
|
problem by letting the user disable the workaround.
|
|
|
|
mga= [HW,DRM]
|
|
|
|
mousedev.tap_time=
|
|
[MOUSE] Maximum time between finger touching and
|
|
leaving touchpad surface for touch to be considered
|
|
a tap and be reported as a left button click (for
|
|
touchpads working in absolute mode only).
|
|
Format: <msecs>
|
|
mousedev.xres= [MOUSE] Horizontal screen resolution, used for devices
|
|
reporting absolute coordinates, such as tablets
|
|
mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
|
|
reporting absolute coordinates, such as tablets
|
|
|
|
mpu401= [HW,OSS]
|
|
Format: <io>,<irq>
|
|
|
|
MTD_Partition= [MTD]
|
|
Format: <name>,<region-number>,<size>,<offset>
|
|
|
|
MTD_Region= [MTD] Format:
|
|
<name>,<region-number>[,<base>,<size>,<buswidth>,<altbuswidth>]
|
|
|
|
mtdparts= [MTD]
|
|
See drivers/mtd/cmdlinepart.c.
|
|
|
|
mtouchusb.raw_coordinates=
|
|
[HW] Make the MicroTouch USB driver use raw coordinates
|
|
('y', default) or cooked coordinates ('n')
|
|
|
|
n2= [NET] SDL Inc. RISCom/N2 synchronous serial card
|
|
|
|
NCR_D700= [HW,SCSI]
|
|
See header of drivers/scsi/NCR_D700.c.
|
|
|
|
ncr5380= [HW,SCSI]
|
|
|
|
ncr53c400= [HW,SCSI]
|
|
|
|
ncr53c400a= [HW,SCSI]
|
|
|
|
ncr53c406a= [HW,SCSI]
|
|
|
|
ncr53c8xx= [HW,SCSI]
|
|
|
|
netdev= [NET] Network devices parameters
|
|
Format: <irq>,<io>,<mem_start>,<mem_end>,<name>
|
|
Note that mem_start is often overloaded to mean
|
|
something different and driver-specific.
|
|
This usage is only documented in each driver source
|
|
file if at all.
|
|
|
|
nfsaddrs= [NFS]
|
|
See Documentation/filesystems/nfsroot.txt.
|
|
|
|
nfsroot= [NFS] nfs root filesystem for disk-less boxes.
|
|
See Documentation/filesystems/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.
|
|
|
|
nfs.enable_ino64=
|
|
[NFS] enable 64-bit inode numbers.
|
|
If zero, the NFS client will fake up a 32-bit inode
|
|
number for the readdir() and stat() syscalls instead
|
|
of returning the full 64-bit number.
|
|
The default is to return 64-bit inode numbers.
|
|
|
|
nmi_debug= [KNL,AVR32] Specify one or more actions to take
|
|
when a NMI is triggered.
|
|
Format: [state][,regs][,debounce][,die]
|
|
|
|
nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels
|
|
|
|
no387 [BUGS=X86-32] Tells the kernel to use the 387 maths
|
|
emulation library even if a 387 maths coprocessor
|
|
is present.
|
|
|
|
noaliencache [MM, NUMA, SLAB] Disables the allocation of alien
|
|
caches in the slab allocator. Saves per-node memory,
|
|
but will impact performance.
|
|
|
|
noalign [KNL,ARM]
|
|
|
|
noapic [SMP,APIC] Tells the kernel to not make use of any
|
|
IOAPICs that may be present in the system.
|
|
|
|
nobats [PPC] Do not use BATs for mapping kernel lowmem
|
|
on "Classic" PPC cores.
|
|
|
|
nocache [ARM]
|
|
|
|
nodelayacct [KNL] Disable per-task delay accounting
|
|
|
|
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
|
|
|
|
noefi [X86-32,X86-64] Disable EFI runtime services support.
|
|
|
|
noexec [IA-64]
|
|
|
|
noexec [X86-32,X86-64]
|
|
On X86-32 available only on PAE configured kernels.
|
|
noexec=on: enable non-executable mappings (default)
|
|
noexec=off: disable non-executable mappings
|
|
|
|
noexec32 [X86-64]
|
|
This affects only 32-bit executables.
|
|
noexec32=on: enable non-executable mappings (default)
|
|
read doesn't imply executable mappings
|
|
noexec32=off: disable non-executable mappings
|
|
read implies executable mappings
|
|
|
|
nofxsr [BUGS=X86-32] Disables x86 floating point extended
|
|
register save and restore. The kernel will only save
|
|
legacy floating-point registers on task switch.
|
|
|
|
noclflush [BUGS=X86] Don't use the CLFLUSH instruction
|
|
|
|
nohlt [BUGS=ARM]
|
|
|
|
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
|
|
instruction doesn't work correctly and not to
|
|
use it.
|
|
|
|
nohalt [IA-64] Tells the kernel not to use the power saving
|
|
function PAL_HALT_LIGHT when idle. This increases
|
|
power-consumption. On the positive side, it reduces
|
|
interrupt wake-up latency, which may improve performance
|
|
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 [X86-32,SMP,KNL] Disable kernel irq balancing
|
|
|
|
noirqdebug [X86-32] Disables the code which attempts to detect and
|
|
disable unhandled interrupt sources.
|
|
|
|
no_timer_check [X86-32,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
|
|
initial RAM disk.
|
|
|
|
nointroute [IA-64]
|
|
|
|
nojitter [IA64] Disables jitter checking for ITC timers.
|
|
|
|
nolapic [X86-32,APIC] Do not enable or use the local APIC.
|
|
|
|
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
|
|
|
|
noltlbs [PPC] Do not use large page/tlb entries for kernel
|
|
lowmem mapping on PPC40x.
|
|
|
|
nomca [IA-64] Disable machine check abort handling
|
|
|
|
nomce [X86-32] Machine Check Exception
|
|
|
|
nomfgpt [X86-32] Disable Multi-Function General Purpose
|
|
Timer usage (for AMD Geode machines).
|
|
|
|
noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops
|
|
|
|
noreplace-smp [X86-32,SMP] Don't replace SMP instructions
|
|
with UP alternatives
|
|
|
|
noresidual [PPC] Don't use residual data on PReP machines.
|
|
|
|
noresume [SWSUSP] Disables resume and restores original swap
|
|
space.
|
|
|
|
no-scroll [VGA] Disables scrollback.
|
|
This is required for the Braillex ib80-piezo Braille
|
|
reader made by F.H. Papenmeier (Germany).
|
|
|
|
nosbagart [IA-64]
|
|
|
|
nosep [BUGS=X86-32] Disables x86 SYSENTER/SYSEXIT support.
|
|
|
|
nosmp [SMP] Tells an SMP kernel to act as a UP kernel,
|
|
and disable the IO APIC. legacy for "maxcpus=0".
|
|
|
|
nosoftlockup [KNL] Disable the soft-lockup detector.
|
|
|
|
nosync [HW,M68K] Disables sync negotiation for all devices.
|
|
|
|
notsc [BUGS=X86-32] Disable Time Stamp Counter
|
|
|
|
nousb [USB] Disable the USB subsystem
|
|
|
|
nowb [ARM]
|
|
|
|
nptcg= [IA64] Override max number of concurrent global TLB
|
|
purges which is reported from either PAL_VM_SUMMARY or
|
|
SAL PALO.
|
|
|
|
numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
|
|
one of ['zone', 'node', 'default'] can be specified
|
|
This can be set from sysctl after boot.
|
|
See Documentation/sysctl/vm.txt for details.
|
|
|
|
nr_uarts= [SERIAL] maximum number of UARTs to be registered.
|
|
|
|
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
|
|
Rather than timing out after 20 ms if an EC
|
|
command is not properly ACKed, override the length
|
|
of the timeout. We have interrupts disabled while
|
|
waiting for the ACK, so if this is set too high
|
|
interrupts *may* be lost!
|
|
|
|
opl3= [HW,OSS]
|
|
Format: <io>
|
|
|
|
oprofile.timer= [HW]
|
|
Use timer interrupt instead of performance counters
|
|
|
|
osst= [HW,SCSI] SCSI Tape Driver
|
|
Format: <buffer_size>,<write_threshold>
|
|
See also Documentation/scsi/st.txt.
|
|
|
|
panic= [KNL] Kernel behaviour on panic
|
|
Format: <timeout>
|
|
|
|
parkbd.port= [HW] Parallel port number the keyboard adapter is
|
|
connected to, default is 0.
|
|
Format: <parport#>
|
|
parkbd.mode= [HW] Parallel port keyboard adapter mode of operation,
|
|
0 for XT, 1 for AT (default is AT).
|
|
Format: <mode>
|
|
|
|
parport= [HW,PPT] Specify parallel ports. 0 disables.
|
|
Format: { 0 | auto | 0xBBB[,IRQ[,DMA]] }
|
|
Use 'auto' to force the driver to use any
|
|
IRQ/DMA settings detected (the default is to
|
|
ignore detected IRQ/DMA settings because of
|
|
possible conflicts). You can specify the base
|
|
address, IRQ, and DMA settings; IRQ and DMA
|
|
should be numbers, or 'auto' (for using detected
|
|
settings on that particular port), or 'nofifo'
|
|
(to avoid using a FIFO even if it is detected).
|
|
Parallel ports are assigned in the order they
|
|
are specified on the command line, starting
|
|
with parport0.
|
|
|
|
parport_init_mode= [HW,PPT]
|
|
Configure VIA parallel port to operate in
|
|
a specific mode. This is necessary on Pegasos
|
|
computer where firmware has no options for setting
|
|
up parallel port mode and sets it to spp.
|
|
Currently this function knows 686a and 8231 chips.
|
|
Format: [spp|ps2|epp|ecp|ecpepp]
|
|
|
|
pas2= [HW,OSS] Format:
|
|
<io>,<irq>,<dma>,<dma16>,<sb_io>,<sb_irq>,<sb_dma>,<sb_dma16>
|
|
|
|
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]
|
|
See header of drivers/block/paride/pcd.c.
|
|
See also Documentation/paride.txt.
|
|
|
|
pci=option[,option...] [PCI] various PCI subsystem options:
|
|
off [X86-32] don't probe for the PCI bus
|
|
bios [X86-32] force use of PCI BIOS, don't access
|
|
the hardware directly. Use this if your machine
|
|
has a non-standard PCI host bridge.
|
|
nobios [X86-32] disallow use of PCI BIOS, only direct
|
|
hardware access methods are allowed. Use this
|
|
if you experience crashes upon bootup and you
|
|
suspect they are caused by the BIOS.
|
|
conf1 [X86-32] Force use of PCI Configuration
|
|
Mechanism 1.
|
|
conf2 [X86-32] Force use of PCI Configuration
|
|
Mechanism 2.
|
|
noaer [PCIE] If the PCIEAER kernel config parameter is
|
|
enabled, this kernel boot option can be used to
|
|
disable the use of PCIE advanced error reporting.
|
|
nodomains [PCI] Disable support for multiple PCI
|
|
root domains (aka PCI segments, in ACPI-speak).
|
|
nommconf [X86-32,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.
|
|
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
|
|
when used, but on other computers it's the only
|
|
way to get the interrupt routing table. Try
|
|
this option if the kernel is unable to allocate
|
|
IRQs or discover secondary PCI buses on your
|
|
motherboard.
|
|
rom [X86-32] Assign address space to expansion ROMs.
|
|
Use with caution as certain devices share
|
|
address decoders between ROMs and other
|
|
resources.
|
|
irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
|
|
assigned automatically to PCI devices. You can
|
|
make the kernel exclude IRQs of your ISA cards
|
|
this way.
|
|
pirqaddr=0xAAAAA [X86-32] Specify the physical address
|
|
of the PIRQ table (normally generated
|
|
by the BIOS) if it is outside the
|
|
F0000h-100000h range.
|
|
lastbus=N [X86-32] Scan all buses thru bus #N. Can be
|
|
useful if the kernel is unable to find your
|
|
secondary buses and you want to tell it
|
|
explicitly which ones they are.
|
|
assign-busses [X86-32] Always assign all PCI bus
|
|
numbers ourselves, overriding
|
|
whatever the firmware may have done.
|
|
usepirqmask [X86-32] Honor the possible IRQ mask stored
|
|
in the BIOS $PIR table. This is needed on
|
|
some systems with broken BIOSes, notably
|
|
some HP Pavilion N5400 and Omnibook XE3
|
|
notebooks. This will have no effect if ACPI
|
|
IRQ routing is enabled.
|
|
noacpi [X86-32] Do not use ACPI for IRQ routing
|
|
or for PCI scanning.
|
|
use_crs [X86-32] Use _CRS for PCI resource
|
|
allocation.
|
|
routeirq Do IRQ routing for all PCI devices.
|
|
This is normally done in pci_enable_device(),
|
|
so this option is a temporary workaround
|
|
for broken drivers that don't call it.
|
|
firmware [ARM] Do not re-enumerate the bus but instead
|
|
just use the configuration from the
|
|
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
|
|
|
|
pd. [PARIDE]
|
|
See Documentation/paride.txt.
|
|
|
|
pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at
|
|
boot time.
|
|
Format: { 0 | 1 }
|
|
See arch/parisc/kernel/pdc_chassis.c
|
|
|
|
pf. [PARIDE]
|
|
See Documentation/paride.txt.
|
|
|
|
pg. [PARIDE]
|
|
See Documentation/paride.txt.
|
|
|
|
pirq= [SMP,APIC] Manual mp-table setup
|
|
See Documentation/i386/IO-APIC.txt.
|
|
|
|
plip= [PPT,NET] Parallel port network link
|
|
Format: { parport<nr> | timid | 0 }
|
|
See also Documentation/parport.txt.
|
|
|
|
pnpacpi= [ACPI]
|
|
{ off }
|
|
|
|
pnpbios= [ISAPNP]
|
|
{ on | off | curr | res | no-curr | no-res }
|
|
|
|
pnp_reserve_irq=
|
|
[ISAPNP] Exclude IRQs for the autoconfiguration
|
|
|
|
pnp_reserve_dma=
|
|
[ISAPNP] Exclude DMAs for the autoconfiguration
|
|
|
|
pnp_reserve_io= [ISAPNP] Exclude I/O ports for the autoconfiguration
|
|
Ranges are in pairs (I/O port base and size).
|
|
|
|
pnp_reserve_mem=
|
|
[ISAPNP] Exclude memory regions for the
|
|
autoconfiguration.
|
|
Ranges are in pairs (memory base and size).
|
|
|
|
print-fatal-signals=
|
|
[KNL] debug: print fatal signals
|
|
print-fatal-signals=1: print segfault info to
|
|
the kernel console.
|
|
default: off.
|
|
|
|
printk.time= Show timing data prefixed to each printk message line
|
|
Format: <bool> (1/Y/y=enable, 0/N/n=disable)
|
|
|
|
profile= [KNL] Enable kernel profiling via /proc/profile
|
|
Format: [schedule,]<number>
|
|
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).
|
|
Requires CONFIG_SCHEDSTATS
|
|
Param: "kvm" - profile VM exits.
|
|
|
|
processor.max_cstate= [HW,ACPI]
|
|
Limit processor to maximum C-state
|
|
max_cstate=9 overrides any DMI blacklist limit.
|
|
|
|
processor.nocst [HW,ACPI]
|
|
Ignore the _CST method to determine C-states,
|
|
instead using the legacy FADT method
|
|
|
|
prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk
|
|
before loading.
|
|
See Documentation/ramdisk.txt.
|
|
|
|
psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to
|
|
probe for; one of (bare|imps|exps|lifebook|any).
|
|
psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports
|
|
per second.
|
|
psmouse.resetafter= [HW,MOUSE]
|
|
Try to reset the device after so many bad packets
|
|
(0 = never).
|
|
psmouse.resolution=
|
|
[HW,MOUSE] Set desired mouse resolution, in dpi.
|
|
psmouse.smartscroll=
|
|
[HW,MOUSE] Controls Logitech smartscroll autorepeat.
|
|
0 = disabled, 1 = enabled (default).
|
|
|
|
pss= [HW,OSS] Personal Sound System (ECHO ESC614)
|
|
Format:
|
|
<io>,<mss_io>,<mss_irq>,<mss_dma>,<mpu_io>,<mpu_irq>
|
|
|
|
pt. [PARIDE]
|
|
See Documentation/paride.txt.
|
|
|
|
pty.legacy_count=
|
|
[KNL] Number of legacy pty's. Overwrites compiled-in
|
|
default number.
|
|
|
|
quiet [KNL] Disable most log messages
|
|
|
|
r128= [HW,DRM]
|
|
|
|
raid= [HW,RAID]
|
|
See Documentation/md.txt.
|
|
|
|
ramdisk_blocksize= [RAM]
|
|
See Documentation/ramdisk.txt.
|
|
|
|
ramdisk_size= [RAM] Sizes of RAM disks in kilobytes
|
|
See Documentation/ramdisk.txt.
|
|
|
|
rcupdate.blimit= [KNL,BOOT]
|
|
Set maximum number of finished RCU callbacks to process
|
|
in one batch.
|
|
|
|
rcupdate.qhimark= [KNL,BOOT]
|
|
Set threshold of queued
|
|
RCU callbacks over which batch limiting is disabled.
|
|
|
|
rcupdate.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,
|
|
used for early userspace startup. See initrd.
|
|
|
|
reboot= [BUGS=X86-32,BUGS=ARM,BUGS=IA-64] Rebooting mode
|
|
Format: <reboot_mode>[,<reboot_mode2>[,...]]
|
|
See arch/*/kernel/reboot.c or arch/*/kernel/process.c
|
|
|
|
reserve= [KNL,BUGS] Force the kernel to ignore some iomem area
|
|
|
|
reservetop= [X86-32]
|
|
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_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
|
|
|
|
riscom8= [HW,SERIAL]
|
|
Format: <io_board1>[,<io_board2>[,...<io_boardN>]]
|
|
|
|
ro [KNL] Mount root device read-only on boot
|
|
|
|
root= [KNL] Root filesystem
|
|
|
|
rootdelay= [KNL] Delay (in seconds) to pause before attempting to
|
|
mount the root filesystem
|
|
|
|
rootflags= [KNL] Set root filesystem mount option string
|
|
|
|
rootfstype= [KNL] Set root filesystem type
|
|
|
|
rootwait [KNL] Wait (indefinitely) for root device to show up.
|
|
Useful for devices that are detected asynchronously
|
|
(e.g. USB and MMC devices).
|
|
|
|
root_plug.vendor_id=
|
|
[ROOTPLUG] Override the default vendor ID
|
|
|
|
root_plug.product_id=
|
|
[ROOTPLUG] Override the default product ID
|
|
|
|
root_plug.debug=
|
|
[ROOTPLUG] Enable debugging output
|
|
|
|
rw [KNL] Mount root device read-write on boot
|
|
|
|
S [KNL] Run init in single mode
|
|
|
|
sa1100ir [NET]
|
|
See drivers/net/irda/sa1100_ir.c.
|
|
|
|
sbni= [NET] Granch SBNI12 leased line adapter
|
|
|
|
sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
|
|
Format: <io>[,<timeout>[,<isapnp>]]
|
|
|
|
scsi_debug_*= [SCSI]
|
|
See drivers/scsi/scsi_debug.c.
|
|
|
|
scsi_default_dev_flags=
|
|
[SCSI] SCSI default device flags
|
|
Format: <integer>
|
|
|
|
scsi_dev_flags= [SCSI] Black/white list entry for vendor and model
|
|
Format: <vendor>:<model>:<flags>
|
|
(flags are integer value)
|
|
|
|
scsi_logging_level= [SCSI] a bit mask of logging levels
|
|
See drivers/scsi/scsi_logging.h for bits. Also
|
|
settable via sysctl at dev.scsi.logging_level
|
|
(/proc/sys/dev/scsi/logging_level).
|
|
There is also a nice 'scsi_logging_level' script in the
|
|
S390-tools package, available for download at
|
|
http://www-128.ibm.com/developerworks/linux/linux390/s390-tools-1.5.4.html
|
|
|
|
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.
|
|
0 -- disable.
|
|
1 -- enable.
|
|
Default value is set via kernel config option.
|
|
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=X86-32]
|
|
|
|
shapers= [NET]
|
|
Maximal number of shapers.
|
|
|
|
sim710= [SCSI,HW]
|
|
See header of drivers/scsi/sim710.c.
|
|
|
|
simeth= [IA-64]
|
|
simscsi=
|
|
|
|
slram= [HW,MTD]
|
|
|
|
slub_debug[=options[,slabs]] [MM, SLUB]
|
|
Enabling slub_debug allows one to determine the
|
|
culprit if slab objects become corrupted. Enabling
|
|
slub_debug can create guard zones around objects and
|
|
may poison objects when not in use. Also tracks the
|
|
last alloc / free. For more information see
|
|
Documentation/vm/slub.txt.
|
|
|
|
slub_max_order= [MM, SLUB]
|
|
Determines the maximum allowed order for slabs.
|
|
A high setting may cause OOMs due to memory
|
|
fragmentation. For more information see
|
|
Documentation/vm/slub.txt.
|
|
|
|
slub_min_objects= [MM, SLUB]
|
|
The minimum number of objects per slab. SLUB will
|
|
increase the slab order up to slub_max_order to
|
|
generate a sufficiently large slab able to contain
|
|
the number of objects indicated. The higher the number
|
|
of objects the smaller the overhead of tracking slabs
|
|
and the less frequently locks need to be acquired.
|
|
For more information see Documentation/vm/slub.txt.
|
|
|
|
slub_min_order= [MM, SLUB]
|
|
Determines the mininum page order for slabs. Must be
|
|
lower than slub_max_order.
|
|
For more information see Documentation/vm/slub.txt.
|
|
|
|
slub_nomerge [MM, SLUB]
|
|
Disable merging of slabs with similar size. May be
|
|
necessary if there is some reason to distinguish
|
|
allocs to different slabs. Debug options disable
|
|
merging on their own.
|
|
For more information see Documentation/vm/slub.txt.
|
|
|
|
smart2= [HW]
|
|
Format: <io1>[,<io2>[,...,<io8>]]
|
|
|
|
smp-alt-once [X86-32,SMP] On a hotplug CPU system, only
|
|
attempt to substitute SMP alternatives once at boot.
|
|
|
|
smsc-ircc2.nopnp [HW] Don't use PNP to discover SMC devices
|
|
smsc-ircc2.ircc_cfg= [HW] Device configuration I/O port
|
|
smsc-ircc2.ircc_sir= [HW] SIR base I/O port
|
|
smsc-ircc2.ircc_fir= [HW] FIR base I/O port
|
|
smsc-ircc2.ircc_irq= [HW] IRQ line
|
|
smsc-ircc2.ircc_dma= [HW] DMA channel
|
|
smsc-ircc2.ircc_transceiver= [HW] Transceiver type:
|
|
0: Toshiba Satellite 1800 (GP data pin select)
|
|
1: Fast pin select (default)
|
|
2: ATC IRMode
|
|
|
|
snd-ad1816a= [HW,ALSA]
|
|
|
|
snd-ad1848= [HW,ALSA]
|
|
|
|
snd-ali5451= [HW,ALSA]
|
|
|
|
snd-als100= [HW,ALSA]
|
|
|
|
snd-als4000= [HW,ALSA]
|
|
|
|
snd-azt2320= [HW,ALSA]
|
|
|
|
snd-cmi8330= [HW,ALSA]
|
|
|
|
snd-cmipci= [HW,ALSA]
|
|
|
|
snd-cs4231= [HW,ALSA]
|
|
|
|
snd-cs4232= [HW,ALSA]
|
|
|
|
snd-cs4236= [HW,ALSA]
|
|
|
|
snd-cs4281= [HW,ALSA]
|
|
|
|
snd-cs46xx= [HW,ALSA]
|
|
|
|
snd-dt019x= [HW,ALSA]
|
|
|
|
snd-dummy= [HW,ALSA]
|
|
|
|
snd-emu10k1= [HW,ALSA]
|
|
|
|
snd-ens1370= [HW,ALSA]
|
|
|
|
snd-ens1371= [HW,ALSA]
|
|
|
|
snd-es968= [HW,ALSA]
|
|
|
|
snd-es1688= [HW,ALSA]
|
|
|
|
snd-es18xx= [HW,ALSA]
|
|
|
|
snd-es1938= [HW,ALSA]
|
|
|
|
snd-es1968= [HW,ALSA]
|
|
|
|
snd-fm801= [HW,ALSA]
|
|
|
|
snd-gusclassic= [HW,ALSA]
|
|
|
|
snd-gusextreme= [HW,ALSA]
|
|
|
|
snd-gusmax= [HW,ALSA]
|
|
|
|
snd-hdsp= [HW,ALSA]
|
|
|
|
snd-ice1712= [HW,ALSA]
|
|
|
|
snd-intel8x0= [HW,ALSA]
|
|
|
|
snd-interwave= [HW,ALSA]
|
|
|
|
snd-interwave-stb=
|
|
[HW,ALSA]
|
|
|
|
snd-korg1212= [HW,ALSA]
|
|
|
|
snd-maestro3= [HW,ALSA]
|
|
|
|
snd-mpu401= [HW,ALSA]
|
|
|
|
snd-mtpav= [HW,ALSA]
|
|
|
|
snd-nm256= [HW,ALSA]
|
|
|
|
snd-opl3sa2= [HW,ALSA]
|
|
|
|
snd-opti92x-ad1848=
|
|
[HW,ALSA]
|
|
|
|
snd-opti92x-cs4231=
|
|
[HW,ALSA]
|
|
|
|
snd-opti93x= [HW,ALSA]
|
|
|
|
snd-pmac= [HW,ALSA]
|
|
|
|
snd-rme32= [HW,ALSA]
|
|
|
|
snd-rme96= [HW,ALSA]
|
|
|
|
snd-rme9652= [HW,ALSA]
|
|
|
|
snd-sb8= [HW,ALSA]
|
|
|
|
snd-sb16= [HW,ALSA]
|
|
|
|
snd-sbawe= [HW,ALSA]
|
|
|
|
snd-serial= [HW,ALSA]
|
|
|
|
snd-sgalaxy= [HW,ALSA]
|
|
|
|
snd-sonicvibes= [HW,ALSA]
|
|
|
|
snd-sun-amd7930=
|
|
[HW,ALSA]
|
|
|
|
snd-sun-cs4231= [HW,ALSA]
|
|
|
|
snd-trident= [HW,ALSA]
|
|
|
|
snd-usb-audio= [HW,ALSA,USB]
|
|
|
|
snd-via82xx= [HW,ALSA]
|
|
|
|
snd-virmidi= [HW,ALSA]
|
|
|
|
snd-wavefront= [HW,ALSA]
|
|
|
|
snd-ymfpci= [HW,ALSA]
|
|
|
|
sonypi.*= [HW] Sony Programmable I/O Control Device driver
|
|
See Documentation/sonypi.txt
|
|
|
|
specialix= [HW,SERIAL] Specialix multi-serial port adapter
|
|
See Documentation/specialix.txt.
|
|
|
|
spia_io_base= [HW,MTD]
|
|
spia_fio_base=
|
|
spia_pedr=
|
|
spia_peddr=
|
|
|
|
sscape= [HW,OSS]
|
|
Format: <io>,<irq>,<dma>,<mpu_io>,<mpu_irq>
|
|
|
|
st= [HW,SCSI] SCSI tape parameters (buffers, etc.)
|
|
See Documentation/scsi/st.txt.
|
|
|
|
sti= [PARISC,HW]
|
|
Format: <num>
|
|
Set the STI (builtin display/keyboard on the HP-PARISC
|
|
machines) console (graphic card) which should be used
|
|
as the initial boot-console.
|
|
See also comment in drivers/video/console/sticore.c.
|
|
|
|
sti_font= [HW]
|
|
See comment in drivers/video/console/sticore.c.
|
|
|
|
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]
|
|
|
|
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.
|
|
|
|
tdfx= [HW,DRM]
|
|
|
|
thash_entries= [KNL,NET]
|
|
Set number of hash buckets for TCP connection
|
|
|
|
thermal.act= [HW,ACPI]
|
|
-1: disable all active trip points in all thermal zones
|
|
<degrees C>: override all lowest active trip points
|
|
|
|
thermal.crt= [HW,ACPI]
|
|
-1: disable all critical trip points in all thermal zones
|
|
<degrees C>: lower all critical trip points
|
|
|
|
thermal.nocrt= [HW,ACPI]
|
|
Set to disable actions on ACPI thermal zone
|
|
critical and hot trip points.
|
|
|
|
thermal.off= [HW,ACPI]
|
|
1: disable ACPI thermal control
|
|
|
|
thermal.psv= [HW,ACPI]
|
|
-1: disable all passive trip points
|
|
<degrees C>: override all passive trip points to this value
|
|
|
|
thermal.tzp= [HW,ACPI]
|
|
Specify global default ACPI thermal zone polling rate
|
|
<deci-seconds>: poll all this frequency
|
|
0: no polling (default)
|
|
|
|
tipar.timeout= [HW,PPT]
|
|
Set communications timeout in tenths of a second
|
|
(default 15).
|
|
|
|
tipar.delay= [HW,PPT]
|
|
Set inter-bit delay in microseconds (default 10).
|
|
|
|
tmscsim= [HW,SCSI]
|
|
See comment before function dc390_setup() in
|
|
drivers/scsi/tmscsim.c.
|
|
|
|
tp720= [HW,PS2]
|
|
|
|
trix= [HW,OSS] MediaTrix AudioTrix Pro
|
|
Format:
|
|
<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
|
|
|
|
turbografx.map[2|3]= [HW,JOY]
|
|
TurboGraFX parallel port interface
|
|
Format:
|
|
<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
|
|
See also Documentation/input/joystick-parport.txt
|
|
|
|
u14-34f= [HW,SCSI] UltraStor 14F/34F SCSI host adapter
|
|
See header of drivers/scsi/u14-34f.c.
|
|
|
|
uart401= [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 a negative value won't be autosuspended at all.
|
|
|
|
usbhid.mousepoll=
|
|
[USBHID] The interval which mice are to be polled at.
|
|
|
|
vdso= [X86-32,SH,x86-64]
|
|
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
|
|
vdso=1: enable VDSO (default)
|
|
vdso=0: disable VDSO mapping
|
|
|
|
vdso32= [X86-32,X86-64]
|
|
vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
|
|
vdso32=1: enable 32-bit VDSO (default)
|
|
vdso32=0: disable 32-bit VDSO mapping
|
|
|
|
vector= [IA-64,SMP]
|
|
vector=percpu: enable percpu vector domain
|
|
|
|
video= [FB] Frame buffer configuration
|
|
See Documentation/fb/modedb.txt.
|
|
|
|
vga= [BOOT,X86-32] Select a particular video mode
|
|
See Documentation/i386/boot.txt and
|
|
Documentation/svga.txt.
|
|
Use vga=ask for menu.
|
|
This is actually a boot loader parameter; the value is
|
|
passed to the kernel using a special protocol.
|
|
|
|
vmalloc=nn[KMG] [KNL,BOOT] Forces the vmalloc area to have an exact
|
|
size of <nn>. This can be used to increase the
|
|
minimum size (128MB on x86). It can also be used to
|
|
decrease the size and leave more room for directly
|
|
mapped kernel RAM.
|
|
|
|
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] Perform z/VM CP command after power off.
|
|
Format: <command>
|
|
|
|
waveartist= [HW,OSS]
|
|
Format: <io>,<irq>,<dma>,<dma2>
|
|
|
|
wd33c93= [HW,SCSI]
|
|
See header of drivers/scsi/wd33c93.c.
|
|
|
|
wd7000= [HW,SCSI]
|
|
See header of drivers/scsi/wd7000.c.
|
|
|
|
wdt= [WDT] Watchdog
|
|
See Documentation/watchdog/wdt.txt.
|
|
|
|
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
|
|
xd_geo= See header of drivers/block/xd.c.
|
|
|
|
xirc2ps_cs= [NET,PCMCIA]
|
|
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
|
|
|
|
______________________________________________________________________
|
|
|
|
TODO:
|
|
|
|
Add documentation for ALSA options.
|
|
Add more DRM drivers.
|