diff options
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 203 |
1 files changed, 162 insertions, 41 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index e9e253d..f7a7955 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -40,6 +40,7 @@ parameter is applicable: ALSA ALSA sound support is enabled. APIC APIC support is enabled. APM Advanced Power Management support is enabled. + ARM ARM architecture is enabled. AVR32 AVR32 architecture is enabled. AX25 Appropriate AX.25 support is enabled. BLACKFIN Blackfin architecture is enabled. @@ -48,7 +49,9 @@ parameter is applicable: EDD BIOS Enhanced Disk Drive Services (EDD) is enabled EFI EFI Partitioning (GPT) is enabled EIDE EIDE/ATAPI support is enabled. + EVM Extended Verification Module FB The frame buffer device is enabled. + FTRACE Function tracing enabled. GCOV GCOV profiling is enabled. HW Appropriate hardware is enabled. IA-64 IA-64 architecture is enabled. @@ -69,6 +72,7 @@ parameter is applicable: Documentation/m68k/kernel-options.txt. MCA MCA bus support is enabled. MDA MDA console support is enabled. + MIPS MIPS architecture is enabled. MOUSE Appropriate mouse support is enabled. MSI Message Signaled Interrupts (PCI). MTD MTD (Memory Technology Device) support is enabled. @@ -100,7 +104,6 @@ parameter is applicable: SPARC Sparc architecture is enabled. SWSUSP Software suspend (hibernation) is enabled. SUSPEND System suspend states are enabled. - FTRACE Function tracing enabled. TPM TPM drivers are enabled. TS Appropriate touchscreen support is enabled. UMS USB Mass Storage support is enabled. @@ -115,7 +118,7 @@ parameter is applicable: X86-64 X86-64 architecture is enabled. More X86-64 boot options can be found in Documentation/x86/x86_64/boot-options.txt . - X86 Either 32bit or 64bit x86 (same as X86-32+X86-64) + X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64) XEN Xen support is enabled In addition, the following text indicates that the option: @@ -161,7 +164,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. rsdt -- prefer RSDT over (default) XSDT copy_dsdt -- copy DSDT to memory - See also Documentation/power/pm.txt, pci=noacpi + See also Documentation/power/runtime_pm.txt, pci=noacpi + + acpi_rsdp= [ACPI,EFI,KEXEC] + Pass the RSDP address to the kernel, mostly used + on machines running EFI runtime service to boot the + second kernel for kdump. acpi_apic_instance= [ACPI, IOAPIC] Format: <int> @@ -299,7 +307,20 @@ bytes respectively. Such letter suffixes can also be entirely omitted. behaviour to be specified. Bit 0 enables warnings, bit 1 enables fixups, and bit 2 sends a segfault. - amd_iommu= [HW,X86-84] + align_va_addr= [X86-64] + Align virtual addresses by clearing slice [14:12] when + allocating a VMA at process creation time. This option + gives you up to 3% performance improvement on AMD F15h + machines (where it is enabled by default) for a + CPU-intensive style benchmark, and it can vary highly in + a microbenchmark depending on workload and compiler. + + 32: only for 32-bit processes + 64: only for 64-bit processes + on: enable for both 32- and 64-bit processes + off: disable for both 32- and 64-bit processes + + amd_iommu= [HW,X86-64] Pass parameters to the AMD IOMMU driver in the system. Possible values are: fullflush - enable flushing of IO/TLB entries when @@ -312,7 +333,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b> - See also Documentation/kernel/input/joystick.txt + See also Documentation/input/joystick.txt analog.map= [HW,JOY] Analog joystick and gamepad support Specifies type or capabilities of an analog joystick @@ -371,7 +392,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. atkbd.softrepeat= [HW] Use software keyboard repeat - autotest [IA64] + autotest [IA-64] baycom_epp= [HW,AX25] Format: <io>,<mode> @@ -401,7 +422,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. bttv.radio= Most important insmod options are available as kernel args too. bttv.pll= See Documentation/video4linux/bttv/Insmod-options - bttv.tuner= and Documentation/video4linux/bttv/CARDLIST + bttv.tuner= bulk_remove=off [PPC] This parameter disables the use of the pSeries firmware feature for flushing multiple hpte entries @@ -557,6 +578,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. /proc/<pid>/coredump_filter. See also Documentation/filesystems/proc.txt. + cpuidle.off=1 [CPU_IDLE] + disable the cpuidle sub-system + cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] @@ -684,8 +708,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. uart[8250],mmio32,<addr>[,options] Start an early, polled-mode console on the 8250/16550 UART at the specified I/O port or MMIO address. - MMIO inter-register address stride is either 8bit (mmio) - or 32bit (mmio32). + MMIO inter-register address stride is either 8-bit + (mmio) or 32-bit (mmio32). The options are the same as for ttyS, above. earlyprintk= [X86,SH,BLACKFIN] @@ -719,6 +743,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. edd= [EDD] Format: {"off" | "on" | "skip[mbr]"} + efi_no_storage_paranoia [EFI; X86] + Using this parameter you can use more than 50% of + your efi variable storage. Use this parameter only if + you are really sure that your UEFI does sane gc and + fulfills the spec otherwise your board may brick. + eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. @@ -728,13 +758,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. elevator= [IOSCHED] Format: {"cfq" | "deadline" | "noop"} - See Documentation/block/as-iosched.txt and + See Documentation/block/cfq-iosched.txt and Documentation/block/deadline-iosched.txt for details. - elfcorehdr= [IA64,PPC,SH,X86] + elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] Specifies physical address of start of kernel core - image elf header. Generally kexec loader will - pass this option to capture kernel. + image elf header and optionally the size. Generally + kexec loader will pass this option to capture kernel. See Documentation/kdump/kdump.txt for details. enable_mtrr_cleanup [X86] @@ -764,12 +794,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted. This option is obsoleted by the "netdev=" option, which has equivalent usage. See its documentation for details. + evm= [EVM] + Format: { "fix" } + Permit 'security.evm' to be updated regardless of + current integrity status. + failslab= fail_page_alloc= fail_make_request=[KNL] General fault injection mechanism. Format: <interval>,<probability>,<space>,<times> - See also /Documentation/fault-injection/. + See also Documentation/fault-injection/. floppy= [HW] See Documentation/blockdev/floppy.txt. @@ -797,7 +832,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. tracer at boot up. function-list is a comma separated list of functions. This list can be changed at run time by the set_ftrace_filter file in the debugfs - tracing directory. + tracing directory. ftrace_notrace=[function-list] [FTRACE] Do not trace the functions specified in @@ -835,7 +870,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. hashdist= [KNL,NUMA] Large hashes allocated during boot are distributed across NUMA nodes. Defaults on - for 64bit NUMA, off otherwise. + for 64-bit NUMA, off otherwise. Format: 0 | 1 (for off | on) hcl= [IA-64] SGI's Hardware Graph compatibility layer @@ -914,6 +949,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. i8042.notimeout [HW] Ignore timeout condition signalled by conroller i8042.reset [HW] Reset the controller during init and cleanup i8042.unlock [HW] Unlock (ignore) the keylock + i8042.kbdreset [HW] Reset device connected to KBD port i810= [HW,DRM] @@ -928,6 +964,20 @@ bytes respectively. Such letter suffixes can also be entirely omitted. i8k.restricted [HW] Allow controlling fans only if SYS_ADMIN capability is set. + i915.invert_brightness= + [DRM] Invert the sense of the variable that is used to + set the brightness of the panel backlight. Normally a + brightness value of 0 indicates backlight switched off, + and the maximum of the brightness value sets the backlight + to maximum brightness. If this parameter is set to 0 + (default) and the machine requires it, or this parameter + is set to 1, a brightness value of 0 sets the backlight + to maximum brightness, and the maximum of the brightness + value switches the backlight off. + -1 -- never invert brightness + 0 -- machine default + 1 -- force brightness inversion + icn= [HW,ISDN] Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] @@ -958,6 +1008,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ignore_loglevel [KNL] Ignore loglevel setting - this will print /all/ kernel messages to the console. Useful for debugging. + We also add it as printk module parameter, so users + could change it dynamically, usually by + /sys/module/printk/parameters/ignore_loglevel. ihash_entries= [KNL] Set number of hash buckets for inode cache. @@ -1004,10 +1057,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. DMA. forcedac [x86_64] With this option iommu will not optimize to look - for io virtual address below 32 bit forcing dual + 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 + 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 @@ -1018,12 +1071,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. has the capability. With this option, super page will not be supported. intremap= [X86-64, Intel-IOMMU] - Format: { on (default) | off | nosid } on enable Interrupt Remapping (default) off disable Interrupt Remapping nosid disable Source ID checking + no_x2apic_optout + BIOS x2APIC opt-out request will be ignored - inttest= [IA64] + inttest= [IA-64] iomem= Disable strict checking of access to MMIO memory strict regions from userspace. @@ -1040,7 +1094,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nomerge forcesac soft - pt [x86, IA64] + pt [x86, IA-64] io7= [HW] IO7 for Marvel based alpha systems See comment before marvel_specify_io7 in @@ -1171,11 +1225,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) for all guests. - Default is 1 (enabled) if in 64bit or 32bit-PAE mode - - kvm-intel.bypass_guest_pf= - [KVM,Intel] Disables bypassing of guest page faults - on Intel chips. Default is 1 (enabled) + Default is 1 (enabled) if in 64-bit or 32-bit PAE mode. kvm-intel.ept= [KVM,Intel] Disable extended page tables (virtualized MMU) support on capable Intel chips. @@ -1189,6 +1239,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. [KVM,Intel] Disable FlexPriority feature (TPR shadow). Default is 1 (enabled) + kvm-intel.nested= + [KVM,Intel] Enable VMX nesting (nVMX). + Default is 0 (disabled) + kvm-intel.unrestricted_guest= [KVM,Intel] Disable unrestricted guest feature (virtualized real and unpaged mode) on capable @@ -1212,10 +1266,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 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 + libata.dma=4 Compact Flash DMA only Combinations also work, so libata.dma=3 enables DMA for disks and CDROMs, but not CFs. - + libata.ignore_hpa= [LIBATA] Ignore HPA limit libata.ignore_hpa=0 keep BIOS limits (default) libata.ignore_hpa=1 ignore limits, using full disk @@ -1261,6 +1315,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. * dump_id: dump IDENTIFY data. + * disable: Disable this device. + If there are multiple matching configurations changing the same attribute, the last one is used. @@ -1341,7 +1397,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ltpc= [NET] Format: <io>,<irq>,<dma> - machvec= [IA64] Force the use of a particular machine-vector + machvec= [IA-64] Force the use of a particular machine-vector (machvec) in a generic kernel. Example: machvec=hpzx1_swiotlb @@ -1358,9 +1414,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. it is equivalent to "nosmp", which also disables the IO APIC. - max_loop= [LOOP] Maximum number of loopback devices that can - be mounted - Format: <1-256> + max_loop= [LOOP] The number of loop block devices that get + (loop.max_loop) unconditionally pre-created at init time. The default + number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead + of statically allocating a predefined number, loop + devices can be requested on-demand with the + /dev/loop-control interface. mcatest= [IA-64] @@ -1647,6 +1706,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. debugging driver suspend/resume hooks). This may not work reliably with all consoles, but is known to work with serial and VGA consoles. + To facilitate more flexible debugging, we also add + console_suspend, a printk module parameter to control + it. Users could use console_suspend (usually + /sys/module/printk/parameters/console_suspend) to + turn on/off it dynamically. noaliencache [MM, NUMA, SLAB] Disables the allocation of alien caches in the slab allocator. Saves per-node memory, @@ -1744,13 +1808,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nointroute [IA-64] - nojitter [IA64] Disables jitter checking for ITC timers. + nojitter [IA-64] Disables jitter checking for ITC timers. no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver no-kvmapf [X86,KVM] Disable paravirtualized asynchronous page fault handling. + no-steal-acc [X86,KVM] Disable paravirtualized steal time accounting. + steal time is computed, but won't influence scheduler + behaviour + nolapic [X86-32,APIC] Do not enable or use the local APIC. nolapic_timer [X86-32,APIC] Do not use the local APIC timer. @@ -1811,7 +1879,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nox2apic [X86-64,APIC] Do not enable x2APIC mode. - nptcg= [IA64] Override max number of concurrent global TLB + nptcg= [IA-64] Override max number of concurrent global TLB purges which is reported from either PAL_VM_SUMMARY or SAL PALO. @@ -1865,7 +1933,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See Documentation/sound/oss/oss-parameters.txt panic= [KNL] Kernel behaviour on panic: delay <timeout> - seconds before rebooting + timeout > 0: seconds before rebooting + timeout = 0: wait forever + timeout < 0: reboot immediately Format: <timeout> parkbd.port= [HW] Parallel port number the keyboard adapter is @@ -2086,13 +2156,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: { parport<nr> | timid | 0 } See also Documentation/parport.txt. - pmtmr= [X86] Manual setup of pmtmr I/O Port. + pmtmr= [X86] Manual setup of pmtmr I/O Port. Override pmtimer IOPort with a hex value. e.g. pmtmr=0x508 - pnp.debug [PNP] - Enable PNP debug messages. This depends on the - CONFIG_PNP_DEBUG_MESSAGES option. + pnp.debug=1 [PNP] + Enable PNP debug messages (depends on the + CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time + via /sys/module/pnp/parameters/debug. We always show + current resource usage; turning this on also shows + possible settings and some assignment information. pnpacpi= [ACPI] { off } @@ -2170,6 +2243,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. [HW,MOUSE] Controls Logitech smartscroll autorepeat. 0 = disabled, 1 = enabled (default). + pstore.backend= Specify the name of the pstore backend to use + pt. [PARIDE] See Documentation/blockdev/paride.txt. @@ -2241,6 +2316,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. in <PAGE_SIZE> units (needed only for swap files). See Documentation/power/swsusp-and-swap-files.txt + resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to + read the resume files + resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. Useful for devices that are detected asynchronously (e.g. USB and MMC devices). @@ -2261,6 +2339,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ro [KNL] Mount root device read-only on boot root= [KNL] Root filesystem + See name_to_dev_t comment in init/do_mounts.c. rootdelay= [KNL] Delay (in seconds) to pause before attempting to mount the root filesystem @@ -2379,7 +2458,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. Format: <integer> sonypi.*= [HW] Sony Programmable I/O Control Device driver - See Documentation/sonypi.txt + See Documentation/laptops/sonypi.txt specialix= [HW,SERIAL] Specialix multi-serial port adapter See Documentation/serial/specialix.txt. @@ -2551,6 +2630,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. <port#>,<js1>,<js2>,<js3>,<js4>,<js5>,<js6>,<js7> 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 @@ -2565,6 +2649,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 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 @@ -2637,6 +2726,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 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. @@ -2682,6 +2781,28 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 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 Vsyscalls turn into traps and are emulated + reasonably safely. + + native [default] 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; |