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  • 			<port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7>
    
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    			See also Documentation/input/joystick-parport.txt
    
    
    	udbg-immortal	[PPC] When debugging early kernel crashes that
    			happen after console_init() and before a proper 
    			console driver takes over, this boot options might
    			help "seeing" what's going on.
    
    
    	uhash_entries=	[KNL,NET]
    			Set number of hash buckets for UDP/UDP-Lite connections
    
    
    	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.
    
    
    	unknown_nmi_panic
    
    			[X86] Cause panic on unknown NMI.
    
    	usbcore.authorized_default=
    			[USB] Default USB device authorization:
    			(default -1 = authorized except for wireless USB,
    			0 = not authorized, 1 = authorized)
    
    
    	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.
    
    	usbcore.usbfs_snoop=
    			[USB] Set to log all usbfs traffic (default 0 = off).
    
    	usbcore.blinkenlights=
    			[USB] Set to cycle leds on hubs (default 0 = off).
    
    	usbcore.old_scheme_first=
    			[USB] Start with the old device initialization
    			scheme (default 0 = off).
    
    
    	usbcore.usbfs_memory_mb=
    			[USB] Memory limit (in MB) for buffers allocated by
    			usbfs (default = 16, 0 = max = 2047).
    
    
    	usbcore.use_both_schemes=
    			[USB] Try the other device initialization scheme
    			if the first one fails (default 1 = enabled).
    
    	usbcore.initial_descriptor_timeout=
    			[USB] Specifies timeout for the initial 64-byte
                            USB_REQ_GET_DESCRIPTOR request in milliseconds
    			(default 5000 = 5.0 seconds).
    
    
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    	usbhid.mousepoll=
    			[USBHID] The interval which mice are to be polled at.
    
    	usb-storage.delay_use=
    			[UMS] The delay in seconds before a new device is
    			scanned for Logical Units (default 5).
    
    	usb-storage.quirks=
    			[UMS] A list of quirks entries to supplement or
    			override the built-in unusual_devs list.  List
    			entries are separated by commas.  Each entry has
    			the form VID:PID:Flags where VID and PID are Vendor
    			and Product ID values (4-digit hex numbers) and
    			Flags is a set of characters, each corresponding
    			to a common usb-storage quirk flag as follows:
    
    				a = SANE_SENSE (collect more than 18 bytes
    					of sense data);
    
    				b = BAD_SENSE (don't collect more than 18
    					bytes of sense data);
    
    				c = FIX_CAPACITY (decrease the reported
    					device capacity by one sector);
    
    				d = NO_READ_DISC_INFO (don't use
    					READ_DISC_INFO command);
    				e = NO_READ_CAPACITY_16 (don't use
    					READ_CAPACITY_16 command);
    
    				h = CAPACITY_HEURISTICS (decrease the
    					reported device capacity by one
    					sector if the number is odd);
    
    				i = IGNORE_DEVICE (don't bind to this
    					device);
    				l = NOT_LOCKABLE (don't try to lock and
    					unlock ejectable media);
    				m = MAX_SECTORS_64 (don't transfer more
    					than 64 sectors = 32 KB at a time);
    
    				n = INITIAL_READ10 (force a retry of the
    					initial READ(10) command);
    
    				o = CAPACITY_OK (accept the capacity
    					reported by the device);
    
    				p = WRITE_CACHE (the device cache is ON
    					by default);
    
    				r = IGNORE_RESIDUE (the device reports
    					bogus residue values);
    				s = SINGLE_LUN (the device has only one
    					Logical Unit);
    				w = NO_WP_DETECT (don't test whether the
    					medium is write-protected).
    			Example: quirks=0419:aaf5:rl,0421:0433:rc
    
    
    	user_debug=	[KNL,ARM]
    			Format: <int>
    			See arch/arm/Kconfig.debug help text.
    				 1 - undefined instruction events
    				 2 - system calls
    				 4 - invalid data aborts
    				 8 - SIGSEGV faults
    				16 - SIGBUS faults
    			Example: user_debug=31
    
    
    	userpte=
    			[X86] Flags controlling user PTE allocations.
    
    				nohigh = do not allocate PTE pages in
    					HIGHMEM regardless of setting
    					of CONFIG_HIGHPTE.
    
    
    			vdso=2: enable compat VDSO (default with COMPAT_VDSO)
    
    			vdso=1: enable VDSO (default)
    			vdso=0: disable VDSO mapping
    
    
    			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
    
    
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    	video=		[FB] Frame buffer configuration
    			See Documentation/fb/modedb.txt.
    
    
    	virtio_mmio.device=
    			[VMMIO] Memory mapped virtio (platform) device.
    
    				<size>@<baseaddr>:<irq>[:<id>]
    			where:
    				<size>     := size (can use standard suffixes
    						like K, M and G)
    				<baseaddr> := physical base address
    				<irq>      := interrupt number (as passed to
    						request_irq())
    				<id>       := (optional) platform device id
    			example:
    				virtio_mmio.device=1K@0x100b0000:48:7
    
    			Can be used multiple times for multiple devices.
    
    
    	vga=		[BOOT,X86-32] Select a particular video mode
    
    			See Documentation/x86/boot.txt and
    
    			Documentation/svga.txt.
    
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    			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
    
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    			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>
    
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    	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>
    
    	vsyscall=	[X86-64]
    			Controls the behavior of vsyscalls (i.e. calls to
    			fixed addresses of 0xffffffffff600x00 from legacy
    			code).  Most statically-linked binaries and older
    			versions of glibc use these calls.  Because these
    			functions are at fixed addresses, they make nice
    			targets for exploits that can control RIP.
    
    
    			emulate     [default] Vsyscalls turn into traps and are
    			            emulated reasonably safely.
    
    			native      Vsyscalls are native syscall instructions.
    
    			            This is a little bit faster than trapping
    			            and makes a few dynamic recompilers work
    			            better than they would in emulation mode.
    			            It also makes exploits much easier to write.
    
    			none        Vsyscalls don't work at all.  This makes
    			            them quite hard to use for exploits but
    			            might break your system.
    
    
    	vt.cur_default=	[VT] Default cursor shape.
    			Format: 0xCCBBAA, where AA, BB, and CC are the same as
    			the parameters of the <Esc>[?A;B;Cc escape sequence;
    			see VGA-softcursor.txt. Default: 2 = underline.
    
    
    	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.
    
    
    	vt.global_cursor_default=
    			[VT]
    			Format=<-1|0|1>
    			Set system-wide default for whether a cursor
    			is shown on new VTs. Default is -1,
    			i.e. cursors will be created by default unless
    			overridden by individual drivers. 0 will hide
    			cursors, 1 will display them.
    
    
    	watchdog timers	[HW,WDT] For information on watchdog timers,
    			see Documentation/watchdog/watchdog-parameters.txt
    			or other driver-specific files in the
    			Documentation/watchdog/ directory.
    
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    	x2apic_phys	[X86-64,APIC] Use x2apic physical mode instead of
    			default x2apic cluster mode on platforms
    			supporting x2apic.
    
    
    	x86_mrst_timer= [X86-32,APBT]
    			Choose timer option for x86 Moorestown MID platform.
    			Two valid options are apbt timer only and lapic timer
    			plus one apbt timer for broadcast timer.
    			x86_mrst_timer=apbt_only | lapic_and_apbt
    
    
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    	xd=		[HW,XT] Original XT pre-IDE (RLL encoded) disks.
    	xd_geo=		See header of drivers/block/xd.c.
    
    
    	xen_emul_unplug=		[HW,X86,XEN]
    			Unplug Xen emulated devices
    			Format: [unplug0,][unplug1]
    			ide-disks -- unplug primary master IDE devices
    			aux-ide-disks -- unplug non-primary-master IDE devices
    			nics -- unplug network devices
    			all -- unplug all emulated devices (NICs and IDE disks)
    
    			unnecessary -- unplugging emulated devices is
    				unnecessary even if the host did not respond to
    				the unplug protocol
    
    			never -- do not unplug even if version check succeeds
    
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    	xirc2ps_cs=	[NET,PCMCIA]
    
    			Format:
    			<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
    
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    ______________________________________________________________________
    
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    TODO:
    
    	Add more DRM drivers.