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-rw-r--r--Documentation/kernel-parameters.txt147
1 files changed, 118 insertions, 29 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 736d45602886..2b2407d9a6d0 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -54,9 +54,11 @@ parameter is applicable:
54 IMA Integrity measurement architecture is enabled. 54 IMA Integrity measurement architecture is enabled.
55 IOSCHED More than one I/O scheduler is enabled. 55 IOSCHED More than one I/O scheduler is enabled.
56 IP_PNP IP DHCP, BOOTP, or RARP is enabled. 56 IP_PNP IP DHCP, BOOTP, or RARP is enabled.
57 IPV6 IPv6 support is enabled.
57 ISAPNP ISA PnP code is enabled. 58 ISAPNP ISA PnP code is enabled.
58 ISDN Appropriate ISDN support is enabled. 59 ISDN Appropriate ISDN support is enabled.
59 JOY Appropriate joystick support is enabled. 60 JOY Appropriate joystick support is enabled.
61 KGDB Kernel debugger support is enabled.
60 KVM Kernel Virtual Machine support is enabled. 62 KVM Kernel Virtual Machine support is enabled.
61 LIBATA Libata driver is enabled 63 LIBATA Libata driver is enabled
62 LP Printer support is enabled. 64 LP Printer support is enabled.
@@ -98,6 +100,7 @@ parameter is applicable:
98 SWSUSP Software suspend (hibernation) is enabled. 100 SWSUSP Software suspend (hibernation) is enabled.
99 SUSPEND System suspend states are enabled. 101 SUSPEND System suspend states are enabled.
100 FTRACE Function tracing enabled. 102 FTRACE Function tracing enabled.
103 TPM TPM drivers are enabled.
101 TS Appropriate touchscreen support is enabled. 104 TS Appropriate touchscreen support is enabled.
102 UMS USB Mass Storage support is enabled. 105 UMS USB Mass Storage support is enabled.
103 USB USB support is enabled. 106 USB USB support is enabled.
@@ -142,14 +145,14 @@ and is between 256 and 4096 characters. It is defined in the file
142 145
143 acpi= [HW,ACPI,X86] 146 acpi= [HW,ACPI,X86]
144 Advanced Configuration and Power Interface 147 Advanced Configuration and Power Interface
145 Format: { force | off | ht | strict | noirq | rsdt } 148 Format: { force | off | strict | noirq | rsdt }
146 force -- enable ACPI if default was off 149 force -- enable ACPI if default was off
147 off -- disable ACPI if default was on 150 off -- disable ACPI if default was on
148 noirq -- do not use ACPI for IRQ routing 151 noirq -- do not use ACPI for IRQ routing
149 ht -- run only enough ACPI to enable Hyper Threading
150 strict -- Be less tolerant of platforms that are not 152 strict -- Be less tolerant of platforms that are not
151 strictly ACPI specification compliant. 153 strictly ACPI specification compliant.
152 rsdt -- prefer RSDT over (default) XSDT 154 rsdt -- prefer RSDT over (default) XSDT
155 copy_dsdt -- copy DSDT to memory
153 156
154 See also Documentation/power/pm.txt, pci=noacpi 157 See also Documentation/power/pm.txt, pci=noacpi
155 158
@@ -251,8 +254,8 @@ and is between 256 and 4096 characters. It is defined in the file
251 control method, with respect to putting devices into 254 control method, with respect to putting devices into
252 low power states, to be enforced (the ACPI 2.0 ordering 255 low power states, to be enforced (the ACPI 2.0 ordering
253 of _PTS is used by default). 256 of _PTS is used by default).
254 s4_nonvs prevents the kernel from saving/restoring the 257 nonvs prevents the kernel from saving/restoring the
255 ACPI NVS memory during hibernation. 258 ACPI NVS memory during suspend/hibernation and resume.
256 sci_force_enable causes the kernel to set SCI_EN directly 259 sci_force_enable causes the kernel to set SCI_EN directly
257 on resume from S1/S3 (which is against the ACPI spec, 260 on resume from S1/S3 (which is against the ACPI spec,
258 but some broken systems don't work without it). 261 but some broken systems don't work without it).
@@ -286,9 +289,6 @@ and is between 256 and 4096 characters. It is defined in the file
286 advansys= [HW,SCSI] 289 advansys= [HW,SCSI]
287 See header of drivers/scsi/advansys.c. 290 See header of drivers/scsi/advansys.c.
288 291
289 advwdt= [HW,WDT] Advantech WDT
290 Format: <iostart>,<iostop>
291
292 aedsp16= [HW,OSS] Audio Excel DSP 16 292 aedsp16= [HW,OSS] Audio Excel DSP 16
293 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> 293 Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq>
294 See also header of sound/oss/aedsp16.c. 294 See also header of sound/oss/aedsp16.c.
@@ -311,18 +311,20 @@ and is between 256 and 4096 characters. It is defined in the file
311 aic79xx= [HW,SCSI] 311 aic79xx= [HW,SCSI]
312 See Documentation/scsi/aic79xx.txt. 312 See Documentation/scsi/aic79xx.txt.
313 313
314 alignment= [KNL,ARM]
315 Allow the default userspace alignment fault handler
316 behaviour to be specified. Bit 0 enables warnings,
317 bit 1 enables fixups, and bit 2 sends a segfault.
318
314 amd_iommu= [HW,X86-84] 319 amd_iommu= [HW,X86-84]
315 Pass parameters to the AMD IOMMU driver in the system. 320 Pass parameters to the AMD IOMMU driver in the system.
316 Possible values are: 321 Possible values are:
317 isolate - enable device isolation (each device, as far
318 as possible, will get its own protection
319 domain) [default]
320 share - put every device behind one IOMMU into the
321 same protection domain
322 fullflush - enable flushing of IO/TLB entries when 322 fullflush - enable flushing of IO/TLB entries when
323 they are unmapped. Otherwise they are 323 they are unmapped. Otherwise they are
324 flushed before they will be reused, which 324 flushed before they will be reused, which
325 is a lot of faster 325 is a lot of faster
326 off - do not initialize any AMD IOMMU found in
327 the system
326 328
327 amijoy.map= [HW,JOY] Amiga joystick support 329 amijoy.map= [HW,JOY] Amiga joystick support
328 Map of devices attached to JOY0DAT and JOY1DAT 330 Map of devices attached to JOY0DAT and JOY1DAT
@@ -347,6 +349,9 @@ and is between 256 and 4096 characters. It is defined in the file
347 Change the amount of debugging information output 349 Change the amount of debugging information output
348 when initialising the APIC and IO-APIC components. 350 when initialising the APIC and IO-APIC components.
349 351
352 autoconf= [IPV6]
353 See Documentation/networking/ipv6.txt.
354
350 show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller 355 show_lapic= [APIC,X86] Advanced Programmable Interrupt Controller
351 Limit apic dumping. The parameter defines the maximal 356 Limit apic dumping. The parameter defines the maximal
352 number of local apics being dumped. Also it is possible 357 number of local apics being dumped. Also it is possible
@@ -629,6 +634,12 @@ and is between 256 and 4096 characters. It is defined in the file
629 See drivers/char/README.epca and 634 See drivers/char/README.epca and
630 Documentation/serial/digiepca.txt. 635 Documentation/serial/digiepca.txt.
631 636
637 disable= [IPV6]
638 See Documentation/networking/ipv6.txt.
639
640 disable_ipv6= [IPV6]
641 See Documentation/networking/ipv6.txt.
642
632 disable_mtrr_cleanup [X86] 643 disable_mtrr_cleanup [X86]
633 The kernel tries to adjust MTRR layout from continuous 644 The kernel tries to adjust MTRR layout from continuous
634 to discrete, to make X server driver able to add WB 645 to discrete, to make X server driver able to add WB
@@ -698,6 +709,12 @@ and is between 256 and 4096 characters. It is defined in the file
698 The VGA output is eventually overwritten by the real 709 The VGA output is eventually overwritten by the real
699 console. 710 console.
700 711
712 ekgdboc= [X86,KGDB] Allow early kernel console debugging
713 ekgdboc=kbd
714
715 This is desgined to be used in conjunction with
716 the boot argument: earlyprintk=vga
717
701 eata= [HW,SCSI] 718 eata= [HW,SCSI]
702 719
703 edd= [EDD] 720 edd= [EDD]
@@ -740,13 +757,14 @@ and is between 256 and 4096 characters. It is defined in the file
740 Default value is 0. 757 Default value is 0.
741 Value can be changed at runtime via /selinux/enforce. 758 Value can be changed at runtime via /selinux/enforce.
742 759
760 erst_disable [ACPI]
761 Disable Error Record Serialization Table (ERST)
762 support.
763
743 ether= [HW,NET] Ethernet cards parameters 764 ether= [HW,NET] Ethernet cards parameters
744 This option is obsoleted by the "netdev=" option, which 765 This option is obsoleted by the "netdev=" option, which
745 has equivalent usage. See its documentation for details. 766 has equivalent usage. See its documentation for details.
746 767
747 eurwdt= [HW,WDT] Eurotech CPU-1220/1410 onboard watchdog.
748 Format: <io>[,<irq>]
749
750 failslab= 768 failslab=
751 fail_page_alloc= 769 fail_page_alloc=
752 fail_make_request=[KNL] 770 fail_make_request=[KNL]
@@ -774,8 +792,12 @@ and is between 256 and 4096 characters. It is defined in the file
774 as early as possible in order to facilitate early 792 as early as possible in order to facilitate early
775 boot debugging. 793 boot debugging.
776 794
777 ftrace_dump_on_oops 795 ftrace_dump_on_oops[=orig_cpu]
778 [FTRACE] will dump the trace buffers on oops. 796 [FTRACE] will dump the trace buffers on oops.
797 If no parameter is passed, ftrace will dump
798 buffers of all CPUs, but if you pass orig_cpu, it will
799 dump only the buffer of the CPU that triggered the
800 oops.
779 801
780 ftrace_filter=[function-list] 802 ftrace_filter=[function-list]
781 [FTRACE] Limit the functions traced by the function 803 [FTRACE] Limit the functions traced by the function
@@ -833,6 +855,11 @@ and is between 256 and 4096 characters. It is defined in the file
833 hd= [EIDE] (E)IDE hard drive subsystem geometry 855 hd= [EIDE] (E)IDE hard drive subsystem geometry
834 Format: <cyl>,<head>,<sect> 856 Format: <cyl>,<head>,<sect>
835 857
858 hest_disable [ACPI]
859 Disable Hardware Error Source Table (HEST) support;
860 corresponding firmware-first mode error processing
861 logic will be disabled.
862
836 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact 863 highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
837 size of <nn>. This works even on boxes that have no 864 size of <nn>. This works even on boxes that have no
838 highmem otherwise. This also works to reduce highmem 865 highmem otherwise. This also works to reduce highmem
@@ -1102,10 +1129,26 @@ and is between 256 and 4096 characters. It is defined in the file
1102 use the HighMem zone if it exists, and the Normal 1129 use the HighMem zone if it exists, and the Normal
1103 zone if it does not. 1130 zone if it does not.
1104 1131
1105 kgdboc= [HW] kgdb over consoles. 1132 kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
1106 Requires a tty driver that supports console polling. 1133 Format: <Controller#>[,poll interval]
1107 (only serial supported for now) 1134 The controller # is the number of the ehci usb debug
1108 Format: <serial_device>[,baud] 1135 port as it is probed via PCI. The poll interval is
1136 optional and is the number seconds in between
1137 each poll cycle to the debug port in case you need
1138 the functionality for interrupting the kernel with
1139 gdb or control-c on the dbgp connection. When
1140 not using this parameter you use sysrq-g to break into
1141 the kernel debugger.
1142
1143 kgdboc= [KGDB,HW] kgdb over consoles.
1144 Requires a tty driver that supports console polling,
1145 or a supported polling keyboard driver (non-usb).
1146 Serial only format: <serial_device>[,baud]
1147 keyboard only format: kbd
1148 keyboard and serial format: kbd,<serial_device>[,baud]
1149
1150 kgdbwait [KGDB] Stop kernel execution and enter the
1151 kernel debugger at the earliest opportunity.
1109 1152
1110 kmac= [MIPS] korina ethernet MAC address. 1153 kmac= [MIPS] korina ethernet MAC address.
1111 Configure the RouterBoard 532 series on-chip 1154 Configure the RouterBoard 532 series on-chip
@@ -1184,7 +1227,7 @@ and is between 256 and 4096 characters. It is defined in the file
1184 1227
1185 libata.force= [LIBATA] Force configurations. The format is comma 1228 libata.force= [LIBATA] Force configurations. The format is comma
1186 separated list of "[ID:]VAL" where ID is 1229 separated list of "[ID:]VAL" where ID is
1187 PORT[:DEVICE]. PORT and DEVICE are decimal numbers 1230 PORT[.DEVICE]. PORT and DEVICE are decimal numbers
1188 matching port, link or device. Basically, it matches 1231 matching port, link or device. Basically, it matches
1189 the ATA ID string printed on console by libata. If 1232 the ATA ID string printed on console by libata. If
1190 the whole ID part is omitted, the last PORT and DEVICE 1233 the whole ID part is omitted, the last PORT and DEVICE
@@ -1217,10 +1260,12 @@ and is between 256 and 4096 characters. It is defined in the file
1217 * nohrst, nosrst, norst: suppress hard, soft 1260 * nohrst, nosrst, norst: suppress hard, soft
1218 and both resets. 1261 and both resets.
1219 1262
1263 * dump_id: dump IDENTIFY data.
1264
1220 If there are multiple matching configurations changing 1265 If there are multiple matching configurations changing
1221 the same attribute, the last one is used. 1266 the same attribute, the last one is used.
1222 1267
1223 lmb=debug [KNL] Enable lmb debug messages. 1268 memblock=debug [KNL] Enable memblock debug messages.
1224 1269
1225 load_ramdisk= [RAM] List of ramdisks to load from floppy 1270 load_ramdisk= [RAM] List of ramdisks to load from floppy
1226 See Documentation/blockdev/ramdisk.txt. 1271 See Documentation/blockdev/ramdisk.txt.
@@ -1729,6 +1774,9 @@ and is between 256 and 4096 characters. It is defined in the file
1729 nomfgpt [X86-32] Disable Multi-Function General Purpose 1774 nomfgpt [X86-32] Disable Multi-Function General Purpose
1730 Timer usage (for AMD Geode machines). 1775 Timer usage (for AMD Geode machines).
1731 1776
1777 nopat [X86] Disable PAT (page attribute table extension of
1778 pagetables) support.
1779
1732 norandmaps Don't use address space randomization. Equivalent to 1780 norandmaps Don't use address space randomization. Equivalent to
1733 echo 0 > /proc/sys/kernel/randomize_va_space 1781 echo 0 > /proc/sys/kernel/randomize_va_space
1734 1782
@@ -1772,6 +1820,12 @@ and is between 256 and 4096 characters. It is defined in the file
1772 purges which is reported from either PAL_VM_SUMMARY or 1820 purges which is reported from either PAL_VM_SUMMARY or
1773 SAL PALO. 1821 SAL PALO.
1774 1822
1823 nr_cpus= [SMP] Maximum number of processors that an SMP kernel
1824 could support. nr_cpus=n : n >= 1 limits the kernel to
1825 supporting 'n' processors. Later in runtime you can not
1826 use hotplug cpu feature to put more cpu back to online.
1827 just like you compile the kernel NR_CPUS=n
1828
1775 nr_uarts= [SERIAL] maximum number of UARTs to be registered. 1829 nr_uarts= [SERIAL] maximum number of UARTs to be registered.
1776 1830
1777 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. 1831 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA.
@@ -1939,8 +1993,12 @@ and is between 256 and 4096 characters. It is defined in the file
1939 IRQ routing is enabled. 1993 IRQ routing is enabled.
1940 noacpi [X86] Do not use ACPI for IRQ routing 1994 noacpi [X86] Do not use ACPI for IRQ routing
1941 or for PCI scanning. 1995 or for PCI scanning.
1942 use_crs [X86] Use _CRS for PCI resource 1996 use_crs [X86] Use PCI host bridge window information
1943 allocation. 1997 from ACPI. On BIOSes from 2008 or later, this
1998 is enabled by default. If you need to use this,
1999 please report a bug.
2000 nocrs [X86] Ignore PCI host bridge windows from ACPI.
2001 If you need to use this, please report a bug.
1944 routeirq Do IRQ routing for all PCI devices. 2002 routeirq Do IRQ routing for all PCI devices.
1945 This is normally done in pci_enable_device(), 2003 This is normally done in pci_enable_device(),
1946 so this option is a temporary workaround 2004 so this option is a temporary workaround
@@ -1989,6 +2047,16 @@ and is between 256 and 4096 characters. It is defined in the file
1989 force Enable ASPM even on devices that claim not to support it. 2047 force Enable ASPM even on devices that claim not to support it.
1990 WARNING: Forcing ASPM on may cause system lockups. 2048 WARNING: Forcing ASPM on may cause system lockups.
1991 2049
2050 pcie_pme= [PCIE,PM] Native PCIe PME signaling options:
2051 Format: {auto|force}[,nomsi]
2052 auto Use native PCIe PME signaling if the BIOS allows the
2053 kernel to control PCIe config registers of root ports.
2054 force Use native PCIe PME signaling even if the BIOS refuses
2055 to allow the kernel to control the relevant PCIe config
2056 registers.
2057 nomsi Do not use MSI for native PCIe PME signaling (this makes
2058 all PCIe root ports use INTx for everything).
2059
1992 pcmv= [HW,PCMCIA] BadgePAD 4 2060 pcmv= [HW,PCMCIA] BadgePAD 4
1993 2061
1994 pd. [PARIDE] 2062 pd. [PARIDE]
@@ -2205,9 +2273,6 @@ and is between 256 and 4096 characters. It is defined in the file
2205 2273
2206 sched_debug [KNL] Enables verbose scheduler debug messages. 2274 sched_debug [KNL] Enables verbose scheduler debug messages.
2207 2275
2208 sc1200wdt= [HW,WDT] SC1200 WDT (watchdog) driver
2209 Format: <io>[,<timeout>[,<isapnp>]]
2210
2211 scsi_debug_*= [SCSI] 2276 scsi_debug_*= [SCSI]
2212 See drivers/scsi/scsi_debug.c. 2277 See drivers/scsi/scsi_debug.c.
2213 2278
@@ -2579,6 +2644,15 @@ and is between 256 and 4096 characters. It is defined in the file
2579 2644
2580 tp720= [HW,PS2] 2645 tp720= [HW,PS2]
2581 2646
2647 tpm_suspend_pcr=[HW,TPM]
2648 Format: integer pcr id
2649 Specify that at suspend time, the tpm driver
2650 should extend the specified pcr with zeros,
2651 as a workaround for some chips which fail to
2652 flush the last written pcr on TPM_SaveState.
2653 This will guarantee that all the other pcrs
2654 are saved.
2655
2582 trace_buf_size=nn[KMG] 2656 trace_buf_size=nn[KMG]
2583 [FTRACE] will set tracing buffer size. 2657 [FTRACE] will set tracing buffer size.
2584 2658
@@ -2694,6 +2768,13 @@ and is between 256 and 4096 characters. It is defined in the file
2694 medium is write-protected). 2768 medium is write-protected).
2695 Example: quirks=0419:aaf5:rl,0421:0433:rc 2769 Example: quirks=0419:aaf5:rl,0421:0433:rc
2696 2770
2771 userpte=
2772 [X86] Flags controlling user PTE allocations.
2773
2774 nohigh = do not allocate PTE pages in
2775 HIGHMEM regardless of setting
2776 of CONFIG_HIGHPTE.
2777
2697 vdso= [X86,SH] 2778 vdso= [X86,SH]
2698 vdso=2: enable compat VDSO (default with COMPAT_VDSO) 2779 vdso=2: enable compat VDSO (default with COMPAT_VDSO)
2699 vdso=1: enable VDSO (default) 2780 vdso=1: enable VDSO (default)
@@ -2780,13 +2861,21 @@ and is between 256 and 4096 characters. It is defined in the file
2780 wd7000= [HW,SCSI] 2861 wd7000= [HW,SCSI]
2781 See header of drivers/scsi/wd7000.c. 2862 See header of drivers/scsi/wd7000.c.
2782 2863
2783 wdt= [WDT] Watchdog 2864 watchdog timers [HW,WDT] For information on watchdog timers,
2784 See Documentation/watchdog/wdt.txt. 2865 see Documentation/watchdog/watchdog-parameters.txt
2866 or other driver-specific files in the
2867 Documentation/watchdog/ directory.
2785 2868
2786 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of 2869 x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of
2787 default x2apic cluster mode on platforms 2870 default x2apic cluster mode on platforms
2788 supporting x2apic. 2871 supporting x2apic.
2789 2872
2873 x86_mrst_timer= [X86-32,APBT]
2874 Choose timer option for x86 Moorestown MID platform.
2875 Two valid options are apbt timer only and lapic timer
2876 plus one apbt timer for broadcast timer.
2877 x86_mrst_timer=apbt_only | lapic_and_apbt
2878
2790 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. 2879 xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
2791 xd_geo= See header of drivers/block/xd.c. 2880 xd_geo= See header of drivers/block/xd.c.
2792 2881