X86-64 X86-64 architecture is enabled.
More X86-64 boot options can be found in
Documentation/x86_64/boot-options.txt .
+ X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
In addition, the following text indicates that the option:
earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
+ earlyprintk=dbgp
Append ",keep" to not disable it when the real console
takes over.
- Only vga or serial at a time, not both.
+ Only vga or serial or usb debug port at a time.
Currently only ttyS0 and ttyS1 are supported.
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [X86-32, X86_64]
+ elfcorehdr= [IA64,PPC,SH,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.
Defaults to the default architecture's huge page size
if not specified.
+ hlt [BUGS=ARM,SH]
+
+ i8042.debug [HW] Toggle i8042 debug mode
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
mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.
+ memchunk=nn[KMG]
+ [KNL,SH] Allow user to override the default size for
+ per-device physically contiguous DMA buffers.
+
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
or
memmap=0x10000$0x18690000
+ memory_corruption_check=0/1 [X86]
+ Some BIOSes seem to corrupt the first 64k of
+ memory when doing things like suspend/resume.
+ Setting this option will scan the memory
+ looking for corruption. Enabling this will
+ both detect corruption and prevent the kernel
+ from using the memory being corrupted.
+ However, its intended as a diagnostic tool; if
+ repeatable BIOS-originated corruption always
+ affects the same memory, you can use memmap=
+ to prevent the kernel from using that memory.
+
+ memory_corruption_check_size=size [X86]
+ By default it checks for corruption in the low
+ 64k, making this memory unavailable for normal
+ use. Use this parameter to scan for
+ corruption in more or less memory.
+
+ memory_corruption_check_period=seconds [X86]
+ By default it checks for corruption every 60
+ seconds. Use this parameter to check at some
+ other rate. 0 disables periodic checking.
+
memtest= [KNL,X86] Enable memtest
Format: <integer>
range: 0,4 : pattern number
nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects.
+ nodsp [SH] Disable hardware DSP at boot time.
+
noefi [X86-32,X86-64] Disable EFI runtime services support.
noexec [IA-64]
noexec32=off: disable non-executable mappings
read implies executable mappings
+ nofpu [SH] Disable hardware FPU at boot time.
+
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]
+ nohlt [BUGS=ARM,SH]
no-hlt [BUGS=X86-32] Tells the kernel that the hlt
instruction doesn't work correctly and not to
See also Documentation/paride.txt.
pci=option[,option...] [PCI] various PCI subsystem options:
- off [X86-32] don't probe for the PCI bus
+ off [X86] 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.
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
+ conf1 [X86] Force use of PCI Configuration
Mechanism 1.
- conf2 [X86-32] Force use of PCI Configuration
+ conf2 [X86] 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
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.
+ rom [X86] Assign address space to expansion ROMs.
Use with caution as certain devices share
address decoders between ROMs and other
resources.
- norom [X86-32,X86_64] Do not assign address space to
+ norom [X86] Do not assign address space to
expansion ROMs that do not already have
BIOS assigned address ranges.
- irqmask=0xMMMM [X86-32] Set a bit mask of IRQs allowed to be
+ irqmask=0xMMMM [X86] 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
+ pirqaddr=0xAAAAA [X86] 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
+ lastbus=N [X86] 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
+ assign-busses [X86] Always assign all PCI bus
numbers ourselves, overriding
whatever the firmware may have done.
- usepirqmask [X86-32] Honor the possible IRQ mask stored
+ usepirqmask [X86] 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
+ noacpi [X86] Do not use ACPI for IRQ routing
or for PCI scanning.
- use_crs [X86-32] Use _CRS for PCI resource
+ use_crs [X86] Use _CRS for PCI resource
allocation.
routeirq Do IRQ routing for all PCI devices.
This is normally done in pci_enable_device(),
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
+ pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
+ Management.
+ off Disable ASPM.
+ force Enable ASPM even on devices that claim not to support it.
+ WARNING: Forcing ASPM on may cause system lockups.
+
pcmv= [HW,PCMCIA] BadgePAD 4
pd. [PARIDE]
autoconfiguration.
Ranges are in pairs (memory base and size).
+ dynamic_printk
+ Enables pr_debug()/dev_dbg() calls if
+ CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. These can also
+ be switched on/off via <debugfs>/dynamic_printk/modules
+
print-fatal-signals=
[KNL] debug: print fatal signals
print-fatal-signals=1: print segfault info to
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.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).
+
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.