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-rw-r--r--Documentation/kernel-parameters.txt106
1 files changed, 79 insertions, 27 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a70e43edcb65..854ed5ca7e3f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -40,6 +40,7 @@ parameter is applicable:
40 ALSA ALSA sound support is enabled. 40 ALSA ALSA sound support is enabled.
41 APIC APIC support is enabled. 41 APIC APIC support is enabled.
42 APM Advanced Power Management support is enabled. 42 APM Advanced Power Management support is enabled.
43 ARM ARM architecture is enabled.
43 AVR32 AVR32 architecture is enabled. 44 AVR32 AVR32 architecture is enabled.
44 AX25 Appropriate AX.25 support is enabled. 45 AX25 Appropriate AX.25 support is enabled.
45 BLACKFIN Blackfin architecture is enabled. 46 BLACKFIN Blackfin architecture is enabled.
@@ -49,6 +50,7 @@ parameter is applicable:
49 EFI EFI Partitioning (GPT) is enabled 50 EFI EFI Partitioning (GPT) is enabled
50 EIDE EIDE/ATAPI support is enabled. 51 EIDE EIDE/ATAPI support is enabled.
51 FB The frame buffer device is enabled. 52 FB The frame buffer device is enabled.
53 FTRACE Function tracing enabled.
52 GCOV GCOV profiling is enabled. 54 GCOV GCOV profiling is enabled.
53 HW Appropriate hardware is enabled. 55 HW Appropriate hardware is enabled.
54 IA-64 IA-64 architecture is enabled. 56 IA-64 IA-64 architecture is enabled.
@@ -69,6 +71,7 @@ parameter is applicable:
69 Documentation/m68k/kernel-options.txt. 71 Documentation/m68k/kernel-options.txt.
70 MCA MCA bus support is enabled. 72 MCA MCA bus support is enabled.
71 MDA MDA console support is enabled. 73 MDA MDA console support is enabled.
74 MIPS MIPS architecture is enabled.
72 MOUSE Appropriate mouse support is enabled. 75 MOUSE Appropriate mouse support is enabled.
73 MSI Message Signaled Interrupts (PCI). 76 MSI Message Signaled Interrupts (PCI).
74 MTD MTD (Memory Technology Device) support is enabled. 77 MTD MTD (Memory Technology Device) support is enabled.
@@ -100,7 +103,6 @@ parameter is applicable:
100 SPARC Sparc architecture is enabled. 103 SPARC Sparc architecture is enabled.
101 SWSUSP Software suspend (hibernation) is enabled. 104 SWSUSP Software suspend (hibernation) is enabled.
102 SUSPEND System suspend states are enabled. 105 SUSPEND System suspend states are enabled.
103 FTRACE Function tracing enabled.
104 TPM TPM drivers are enabled. 106 TPM TPM drivers are enabled.
105 TS Appropriate touchscreen support is enabled. 107 TS Appropriate touchscreen support is enabled.
106 UMS USB Mass Storage support is enabled. 108 UMS USB Mass Storage support is enabled.
@@ -115,7 +117,7 @@ parameter is applicable:
115 X86-64 X86-64 architecture is enabled. 117 X86-64 X86-64 architecture is enabled.
116 More X86-64 boot options can be found in 118 More X86-64 boot options can be found in
117 Documentation/x86/x86_64/boot-options.txt . 119 Documentation/x86/x86_64/boot-options.txt .
118 X86 Either 32bit or 64bit x86 (same as X86-32+X86-64) 120 X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
119 XEN Xen support is enabled 121 XEN Xen support is enabled
120 122
121In addition, the following text indicates that the option: 123In addition, the following text indicates that the option:
@@ -163,6 +165,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
163 165
164 See also Documentation/power/pm.txt, pci=noacpi 166 See also Documentation/power/pm.txt, pci=noacpi
165 167
168 acpi_rsdp= [ACPI,EFI,KEXEC]
169 Pass the RSDP address to the kernel, mostly used
170 on machines running EFI runtime service to boot the
171 second kernel for kdump.
172
166 acpi_apic_instance= [ACPI, IOAPIC] 173 acpi_apic_instance= [ACPI, IOAPIC]
167 Format: <int> 174 Format: <int>
168 2: use 2nd APIC table, if available 175 2: use 2nd APIC table, if available
@@ -371,7 +378,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
371 atkbd.softrepeat= [HW] 378 atkbd.softrepeat= [HW]
372 Use software keyboard repeat 379 Use software keyboard repeat
373 380
374 autotest [IA64] 381 autotest [IA-64]
375 382
376 baycom_epp= [HW,AX25] 383 baycom_epp= [HW,AX25]
377 Format: <io>,<mode> 384 Format: <io>,<mode>
@@ -546,6 +553,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
546 /proc/<pid>/coredump_filter. 553 /proc/<pid>/coredump_filter.
547 See also Documentation/filesystems/proc.txt. 554 See also Documentation/filesystems/proc.txt.
548 555
556 cpuidle.off=1 [CPU_IDLE]
557 disable the cpuidle sub-system
558
549 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver 559 cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
550 Format: 560 Format:
551 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] 561 <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
@@ -673,8 +683,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
673 uart[8250],mmio32,<addr>[,options] 683 uart[8250],mmio32,<addr>[,options]
674 Start an early, polled-mode console on the 8250/16550 684 Start an early, polled-mode console on the 8250/16550
675 UART at the specified I/O port or MMIO address. 685 UART at the specified I/O port or MMIO address.
676 MMIO inter-register address stride is either 8bit (mmio) 686 MMIO inter-register address stride is either 8-bit
677 or 32bit (mmio32). 687 (mmio) or 32-bit (mmio32).
678 The options are the same as for ttyS, above. 688 The options are the same as for ttyS, above.
679 689
680 earlyprintk= [X86,SH,BLACKFIN] 690 earlyprintk= [X86,SH,BLACKFIN]
@@ -717,7 +727,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
717 See Documentation/block/as-iosched.txt and 727 See Documentation/block/as-iosched.txt and
718 Documentation/block/deadline-iosched.txt for details. 728 Documentation/block/deadline-iosched.txt for details.
719 729
720 elfcorehdr= [IA64,PPC,SH,X86] 730 elfcorehdr= [IA-64,PPC,SH,X86]
721 Specifies physical address of start of kernel core 731 Specifies physical address of start of kernel core
722 image elf header. Generally kexec loader will 732 image elf header. Generally kexec loader will
723 pass this option to capture kernel. 733 pass this option to capture kernel.
@@ -783,7 +793,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
783 tracer at boot up. function-list is a comma separated 793 tracer at boot up. function-list is a comma separated
784 list of functions. This list can be changed at run 794 list of functions. This list can be changed at run
785 time by the set_ftrace_filter file in the debugfs 795 time by the set_ftrace_filter file in the debugfs
786 tracing directory. 796 tracing directory.
787 797
788 ftrace_notrace=[function-list] 798 ftrace_notrace=[function-list]
789 [FTRACE] Do not trace the functions specified in 799 [FTRACE] Do not trace the functions specified in
@@ -821,7 +831,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
821 831
822 hashdist= [KNL,NUMA] Large hashes allocated during boot 832 hashdist= [KNL,NUMA] Large hashes allocated during boot
823 are distributed across NUMA nodes. Defaults on 833 are distributed across NUMA nodes. Defaults on
824 for 64bit NUMA, off otherwise. 834 for 64-bit NUMA, off otherwise.
825 Format: 0 | 1 (for off | on) 835 Format: 0 | 1 (for off | on)
826 836
827 hcl= [IA-64] SGI's Hardware Graph compatibility layer 837 hcl= [IA-64] SGI's Hardware Graph compatibility layer
@@ -990,10 +1000,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
990 DMA. 1000 DMA.
991 forcedac [x86_64] 1001 forcedac [x86_64]
992 With this option iommu will not optimize to look 1002 With this option iommu will not optimize to look
993 for io virtual address below 32 bit forcing dual 1003 for io virtual address below 32-bit forcing dual
994 address cycle on pci bus for cards supporting greater 1004 address cycle on pci bus for cards supporting greater
995 than 32 bit addressing. The default is to look 1005 than 32-bit addressing. The default is to look
996 for translation below 32 bit and if not available 1006 for translation below 32-bit and if not available
997 then look in the higher range. 1007 then look in the higher range.
998 strict [Default Off] 1008 strict [Default Off]
999 With this option on every unmap_single operation will 1009 With this option on every unmap_single operation will
@@ -1009,7 +1019,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1009 off disable Interrupt Remapping 1019 off disable Interrupt Remapping
1010 nosid disable Source ID checking 1020 nosid disable Source ID checking
1011 1021
1012 inttest= [IA64] 1022 inttest= [IA-64]
1013 1023
1014 iomem= Disable strict checking of access to MMIO memory 1024 iomem= Disable strict checking of access to MMIO memory
1015 strict regions from userspace. 1025 strict regions from userspace.
@@ -1026,7 +1036,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1026 nomerge 1036 nomerge
1027 forcesac 1037 forcesac
1028 soft 1038 soft
1029 pt [x86, IA64] 1039 pt [x86, IA-64]
1030 1040
1031 io7= [HW] IO7 for Marvel based alpha systems 1041 io7= [HW] IO7 for Marvel based alpha systems
1032 See comment before marvel_specify_io7 in 1042 See comment before marvel_specify_io7 in
@@ -1157,7 +1167,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1157 1167
1158 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) 1168 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
1159 for all guests. 1169 for all guests.
1160 Default is 1 (enabled) if in 64bit or 32bit-PAE mode 1170 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
1161 1171
1162 kvm-intel.ept= [KVM,Intel] Disable extended page tables 1172 kvm-intel.ept= [KVM,Intel] Disable extended page tables
1163 (virtualized MMU) support on capable Intel chips. 1173 (virtualized MMU) support on capable Intel chips.
@@ -1194,10 +1204,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1194 libata.dma=0 Disable all PATA and SATA DMA 1204 libata.dma=0 Disable all PATA and SATA DMA
1195 libata.dma=1 PATA and SATA Disk DMA only 1205 libata.dma=1 PATA and SATA Disk DMA only
1196 libata.dma=2 ATAPI (CDROM) DMA only 1206 libata.dma=2 ATAPI (CDROM) DMA only
1197 libata.dma=4 Compact Flash DMA only 1207 libata.dma=4 Compact Flash DMA only
1198 Combinations also work, so libata.dma=3 enables DMA 1208 Combinations also work, so libata.dma=3 enables DMA
1199 for disks and CDROMs, but not CFs. 1209 for disks and CDROMs, but not CFs.
1200 1210
1201 libata.ignore_hpa= [LIBATA] Ignore HPA limit 1211 libata.ignore_hpa= [LIBATA] Ignore HPA limit
1202 libata.ignore_hpa=0 keep BIOS limits (default) 1212 libata.ignore_hpa=0 keep BIOS limits (default)
1203 libata.ignore_hpa=1 ignore limits, using full disk 1213 libata.ignore_hpa=1 ignore limits, using full disk
@@ -1323,7 +1333,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1323 ltpc= [NET] 1333 ltpc= [NET]
1324 Format: <io>,<irq>,<dma> 1334 Format: <io>,<irq>,<dma>
1325 1335
1326 machvec= [IA64] Force the use of a particular machine-vector 1336 machvec= [IA-64] Force the use of a particular machine-vector
1327 (machvec) in a generic kernel. 1337 (machvec) in a generic kernel.
1328 Example: machvec=hpzx1_swiotlb 1338 Example: machvec=hpzx1_swiotlb
1329 1339
@@ -1340,9 +1350,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1340 it is equivalent to "nosmp", which also disables 1350 it is equivalent to "nosmp", which also disables
1341 the IO APIC. 1351 the IO APIC.
1342 1352
1343 max_loop= [LOOP] Maximum number of loopback devices that can 1353 max_loop= [LOOP] The number of loop block devices that get
1344 be mounted 1354 (loop.max_loop) unconditionally pre-created at init time. The default
1345 Format: <1-256> 1355 number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead
1356 of statically allocating a predefined number, loop
1357 devices can be requested on-demand with the
1358 /dev/loop-control interface.
1346 1359
1347 mcatest= [IA-64] 1360 mcatest= [IA-64]
1348 1361
@@ -1726,7 +1739,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1726 1739
1727 nointroute [IA-64] 1740 nointroute [IA-64]
1728 1741
1729 nojitter [IA64] Disables jitter checking for ITC timers. 1742 nojitter [IA-64] Disables jitter checking for ITC timers.
1730 1743
1731 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver 1744 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
1732 1745
@@ -1792,7 +1805,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1792 1805
1793 nox2apic [X86-64,APIC] Do not enable x2APIC mode. 1806 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1794 1807
1795 nptcg= [IA64] Override max number of concurrent global TLB 1808 nptcg= [IA-64] Override max number of concurrent global TLB
1796 purges which is reported from either PAL_VM_SUMMARY or 1809 purges which is reported from either PAL_VM_SUMMARY or
1797 SAL PALO. 1810 SAL PALO.
1798 1811
@@ -1846,7 +1859,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1846 See Documentation/sound/oss/oss-parameters.txt 1859 See Documentation/sound/oss/oss-parameters.txt
1847 1860
1848 panic= [KNL] Kernel behaviour on panic: delay <timeout> 1861 panic= [KNL] Kernel behaviour on panic: delay <timeout>
1849 seconds before rebooting 1862 timeout > 0: seconds before rebooting
1863 timeout = 0: wait forever
1864 timeout < 0: reboot immediately
1850 Format: <timeout> 1865 Format: <timeout>
1851 1866
1852 parkbd.port= [HW] Parallel port number the keyboard adapter is 1867 parkbd.port= [HW] Parallel port number the keyboard adapter is
@@ -2067,13 +2082,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2067 Format: { parport<nr> | timid | 0 } 2082 Format: { parport<nr> | timid | 0 }
2068 See also Documentation/parport.txt. 2083 See also Documentation/parport.txt.
2069 2084
2070 pmtmr= [X86] Manual setup of pmtmr I/O Port. 2085 pmtmr= [X86] Manual setup of pmtmr I/O Port.
2071 Override pmtimer IOPort with a hex value. 2086 Override pmtimer IOPort with a hex value.
2072 e.g. pmtmr=0x508 2087 e.g. pmtmr=0x508
2073 2088
2074 pnp.debug [PNP] 2089 pnp.debug=1 [PNP]
2075 Enable PNP debug messages. This depends on the 2090 Enable PNP debug messages (depends on the
2076 CONFIG_PNP_DEBUG_MESSAGES option. 2091 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
2092 via /sys/module/pnp/parameters/debug. We always show
2093 current resource usage; turning this on also shows
2094 possible settings and some assignment information.
2077 2095
2078 pnpacpi= [ACPI] 2096 pnpacpi= [ACPI]
2079 { off } 2097 { off }
@@ -2151,6 +2169,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2151 [HW,MOUSE] Controls Logitech smartscroll autorepeat. 2169 [HW,MOUSE] Controls Logitech smartscroll autorepeat.
2152 0 = disabled, 1 = enabled (default). 2170 0 = disabled, 1 = enabled (default).
2153 2171
2172 pstore.backend= Specify the name of the pstore backend to use
2173
2154 pt. [PARIDE] 2174 pt. [PARIDE]
2155 See Documentation/blockdev/paride.txt. 2175 See Documentation/blockdev/paride.txt.
2156 2176
@@ -2236,6 +2256,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2236 ro [KNL] Mount root device read-only on boot 2256 ro [KNL] Mount root device read-only on boot
2237 2257
2238 root= [KNL] Root filesystem 2258 root= [KNL] Root filesystem
2259 See name_to_dev_t comment in init/do_mounts.c.
2239 2260
2240 rootdelay= [KNL] Delay (in seconds) to pause before attempting to 2261 rootdelay= [KNL] Delay (in seconds) to pause before attempting to
2241 mount the root filesystem 2262 mount the root filesystem
@@ -2622,6 +2643,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2622 medium is write-protected). 2643 medium is write-protected).
2623 Example: quirks=0419:aaf5:rl,0421:0433:rc 2644 Example: quirks=0419:aaf5:rl,0421:0433:rc
2624 2645
2646 user_debug= [KNL,ARM]
2647 Format: <int>
2648 See arch/arm/Kconfig.debug help text.
2649 1 - undefined instruction events
2650 2 - system calls
2651 4 - invalid data aborts
2652 8 - SIGSEGV faults
2653 16 - SIGBUS faults
2654 Example: user_debug=31
2655
2625 userpte= 2656 userpte=
2626 [X86] Flags controlling user PTE allocations. 2657 [X86] Flags controlling user PTE allocations.
2627 2658
@@ -2667,6 +2698,27 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2667 vmpoff= [KNL,S390] Perform z/VM CP command after power off. 2698 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2668 Format: <command> 2699 Format: <command>
2669 2700
2701 vsyscall= [X86-64]
2702 Controls the behavior of vsyscalls (i.e. calls to
2703 fixed addresses of 0xffffffffff600x00 from legacy
2704 code). Most statically-linked binaries and older
2705 versions of glibc use these calls. Because these
2706 functions are at fixed addresses, they make nice
2707 targets for exploits that can control RIP.
2708
2709 emulate [default] Vsyscalls turn into traps and are
2710 emulated reasonably safely.
2711
2712 native Vsyscalls are native syscall instructions.
2713 This is a little bit faster than trapping
2714 and makes a few dynamic recompilers work
2715 better than they would in emulation mode.
2716 It also makes exploits much easier to write.
2717
2718 none Vsyscalls don't work at all. This makes
2719 them quite hard to use for exploits but
2720 might break your system.
2721
2670 vt.cur_default= [VT] Default cursor shape. 2722 vt.cur_default= [VT] Default cursor shape.
2671 Format: 0xCCBBAA, where AA, BB, and CC are the same as 2723 Format: 0xCCBBAA, where AA, BB, and CC are the same as
2672 the parameters of the <Esc>[?A;B;Cc escape sequence; 2724 the parameters of the <Esc>[?A;B;Cc escape sequence;