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-rw-r--r--Documentation/kernel-parameters.txt92
1 files changed, 66 insertions, 26 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e279b7242912..d6e6724446c8 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:
@@ -376,7 +378,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
376 atkbd.softrepeat= [HW] 378 atkbd.softrepeat= [HW]
377 Use software keyboard repeat 379 Use software keyboard repeat
378 380
379 autotest [IA64] 381 autotest [IA-64]
380 382
381 baycom_epp= [HW,AX25] 383 baycom_epp= [HW,AX25]
382 Format: <io>,<mode> 384 Format: <io>,<mode>
@@ -681,8 +683,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
681 uart[8250],mmio32,<addr>[,options] 683 uart[8250],mmio32,<addr>[,options]
682 Start an early, polled-mode console on the 8250/16550 684 Start an early, polled-mode console on the 8250/16550
683 UART at the specified I/O port or MMIO address. 685 UART at the specified I/O port or MMIO address.
684 MMIO inter-register address stride is either 8bit (mmio) 686 MMIO inter-register address stride is either 8-bit
685 or 32bit (mmio32). 687 (mmio) or 32-bit (mmio32).
686 The options are the same as for ttyS, above. 688 The options are the same as for ttyS, above.
687 689
688 earlyprintk= [X86,SH,BLACKFIN] 690 earlyprintk= [X86,SH,BLACKFIN]
@@ -725,7 +727,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
725 See Documentation/block/as-iosched.txt and 727 See Documentation/block/as-iosched.txt and
726 Documentation/block/deadline-iosched.txt for details. 728 Documentation/block/deadline-iosched.txt for details.
727 729
728 elfcorehdr= [IA64,PPC,SH,X86] 730 elfcorehdr= [IA-64,PPC,SH,X86]
729 Specifies physical address of start of kernel core 731 Specifies physical address of start of kernel core
730 image elf header. Generally kexec loader will 732 image elf header. Generally kexec loader will
731 pass this option to capture kernel. 733 pass this option to capture kernel.
@@ -791,7 +793,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
791 tracer at boot up. function-list is a comma separated 793 tracer at boot up. function-list is a comma separated
792 list of functions. This list can be changed at run 794 list of functions. This list can be changed at run
793 time by the set_ftrace_filter file in the debugfs 795 time by the set_ftrace_filter file in the debugfs
794 tracing directory. 796 tracing directory.
795 797
796 ftrace_notrace=[function-list] 798 ftrace_notrace=[function-list]
797 [FTRACE] Do not trace the functions specified in 799 [FTRACE] Do not trace the functions specified in
@@ -829,7 +831,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
829 831
830 hashdist= [KNL,NUMA] Large hashes allocated during boot 832 hashdist= [KNL,NUMA] Large hashes allocated during boot
831 are distributed across NUMA nodes. Defaults on 833 are distributed across NUMA nodes. Defaults on
832 for 64bit NUMA, off otherwise. 834 for 64-bit NUMA, off otherwise.
833 Format: 0 | 1 (for off | on) 835 Format: 0 | 1 (for off | on)
834 836
835 hcl= [IA-64] SGI's Hardware Graph compatibility layer 837 hcl= [IA-64] SGI's Hardware Graph compatibility layer
@@ -998,10 +1000,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
998 DMA. 1000 DMA.
999 forcedac [x86_64] 1001 forcedac [x86_64]
1000 With this option iommu will not optimize to look 1002 With this option iommu will not optimize to look
1001 for io virtual address below 32 bit forcing dual 1003 for io virtual address below 32-bit forcing dual
1002 address cycle on pci bus for cards supporting greater 1004 address cycle on pci bus for cards supporting greater
1003 than 32 bit addressing. The default is to look 1005 than 32-bit addressing. The default is to look
1004 for translation below 32 bit and if not available 1006 for translation below 32-bit and if not available
1005 then look in the higher range. 1007 then look in the higher range.
1006 strict [Default Off] 1008 strict [Default Off]
1007 With this option on every unmap_single operation will 1009 With this option on every unmap_single operation will
@@ -1017,7 +1019,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1017 off disable Interrupt Remapping 1019 off disable Interrupt Remapping
1018 nosid disable Source ID checking 1020 nosid disable Source ID checking
1019 1021
1020 inttest= [IA64] 1022 inttest= [IA-64]
1021 1023
1022 iomem= Disable strict checking of access to MMIO memory 1024 iomem= Disable strict checking of access to MMIO memory
1023 strict regions from userspace. 1025 strict regions from userspace.
@@ -1034,7 +1036,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1034 nomerge 1036 nomerge
1035 forcesac 1037 forcesac
1036 soft 1038 soft
1037 pt [x86, IA64] 1039 pt [x86, IA-64]
1038 1040
1039 io7= [HW] IO7 for Marvel based alpha systems 1041 io7= [HW] IO7 for Marvel based alpha systems
1040 See comment before marvel_specify_io7 in 1042 See comment before marvel_specify_io7 in
@@ -1165,7 +1167,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1165 1167
1166 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) 1168 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
1167 for all guests. 1169 for all guests.
1168 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.
1169 1171
1170 kvm-intel.ept= [KVM,Intel] Disable extended page tables 1172 kvm-intel.ept= [KVM,Intel] Disable extended page tables
1171 (virtualized MMU) support on capable Intel chips. 1173 (virtualized MMU) support on capable Intel chips.
@@ -1202,10 +1204,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1202 libata.dma=0 Disable all PATA and SATA DMA 1204 libata.dma=0 Disable all PATA and SATA DMA
1203 libata.dma=1 PATA and SATA Disk DMA only 1205 libata.dma=1 PATA and SATA Disk DMA only
1204 libata.dma=2 ATAPI (CDROM) DMA only 1206 libata.dma=2 ATAPI (CDROM) DMA only
1205 libata.dma=4 Compact Flash DMA only 1207 libata.dma=4 Compact Flash DMA only
1206 Combinations also work, so libata.dma=3 enables DMA 1208 Combinations also work, so libata.dma=3 enables DMA
1207 for disks and CDROMs, but not CFs. 1209 for disks and CDROMs, but not CFs.
1208 1210
1209 libata.ignore_hpa= [LIBATA] Ignore HPA limit 1211 libata.ignore_hpa= [LIBATA] Ignore HPA limit
1210 libata.ignore_hpa=0 keep BIOS limits (default) 1212 libata.ignore_hpa=0 keep BIOS limits (default)
1211 libata.ignore_hpa=1 ignore limits, using full disk 1213 libata.ignore_hpa=1 ignore limits, using full disk
@@ -1331,7 +1333,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1331 ltpc= [NET] 1333 ltpc= [NET]
1332 Format: <io>,<irq>,<dma> 1334 Format: <io>,<irq>,<dma>
1333 1335
1334 machvec= [IA64] Force the use of a particular machine-vector 1336 machvec= [IA-64] Force the use of a particular machine-vector
1335 (machvec) in a generic kernel. 1337 (machvec) in a generic kernel.
1336 Example: machvec=hpzx1_swiotlb 1338 Example: machvec=hpzx1_swiotlb
1337 1339
@@ -1348,9 +1350,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1348 it is equivalent to "nosmp", which also disables 1350 it is equivalent to "nosmp", which also disables
1349 the IO APIC. 1351 the IO APIC.
1350 1352
1351 max_loop= [LOOP] Maximum number of loopback devices that can 1353 max_loop= [LOOP] The number of loop block devices that get
1352 be mounted 1354 (loop.max_loop) unconditionally pre-created at init time. The default
1353 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.
1354 1359
1355 mcatest= [IA-64] 1360 mcatest= [IA-64]
1356 1361
@@ -1734,7 +1739,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1734 1739
1735 nointroute [IA-64] 1740 nointroute [IA-64]
1736 1741
1737 nojitter [IA64] Disables jitter checking for ITC timers. 1742 nojitter [IA-64] Disables jitter checking for ITC timers.
1738 1743
1739 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver 1744 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
1740 1745
@@ -1800,7 +1805,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1800 1805
1801 nox2apic [X86-64,APIC] Do not enable x2APIC mode. 1806 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1802 1807
1803 nptcg= [IA64] Override max number of concurrent global TLB 1808 nptcg= [IA-64] Override max number of concurrent global TLB
1804 purges which is reported from either PAL_VM_SUMMARY or 1809 purges which is reported from either PAL_VM_SUMMARY or
1805 SAL PALO. 1810 SAL PALO.
1806 1811
@@ -2077,13 +2082,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2077 Format: { parport<nr> | timid | 0 } 2082 Format: { parport<nr> | timid | 0 }
2078 See also Documentation/parport.txt. 2083 See also Documentation/parport.txt.
2079 2084
2080 pmtmr= [X86] Manual setup of pmtmr I/O Port. 2085 pmtmr= [X86] Manual setup of pmtmr I/O Port.
2081 Override pmtimer IOPort with a hex value. 2086 Override pmtimer IOPort with a hex value.
2082 e.g. pmtmr=0x508 2087 e.g. pmtmr=0x508
2083 2088
2084 pnp.debug [PNP] 2089 pnp.debug=1 [PNP]
2085 Enable PNP debug messages. This depends on the 2090 Enable PNP debug messages (depends on the
2086 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.
2087 2095
2088 pnpacpi= [ACPI] 2096 pnpacpi= [ACPI]
2089 { off } 2097 { off }
@@ -2635,6 +2643,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2635 medium is write-protected). 2643 medium is write-protected).
2636 Example: quirks=0419:aaf5:rl,0421:0433:rc 2644 Example: quirks=0419:aaf5:rl,0421:0433:rc
2637 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
2638 userpte= 2656 userpte=
2639 [X86] Flags controlling user PTE allocations. 2657 [X86] Flags controlling user PTE allocations.
2640 2658
@@ -2680,6 +2698,28 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2680 vmpoff= [KNL,S390] Perform z/VM CP command after power off. 2698 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2681 Format: <command> 2699 Format: <command>
2682 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 Vsyscalls turn into traps and are emulated
2710 reasonably safely.
2711
2712 native [default] Vsyscalls are native syscall
2713 instructions.
2714 This is a little bit faster than trapping
2715 and makes a few dynamic recompilers work
2716 better than they would in emulation mode.
2717 It also makes exploits much easier to write.
2718
2719 none Vsyscalls don't work at all. This makes
2720 them quite hard to use for exploits but
2721 might break your system.
2722
2683 vt.cur_default= [VT] Default cursor shape. 2723 vt.cur_default= [VT] Default cursor shape.
2684 Format: 0xCCBBAA, where AA, BB, and CC are the same as 2724 Format: 0xCCBBAA, where AA, BB, and CC are the same as
2685 the parameters of the <Esc>[?A;B;Cc escape sequence; 2725 the parameters of the <Esc>[?A;B;Cc escape sequence;