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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 cd7c86110147..d317f6cf0d35 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.
@@ -50,6 +51,7 @@ parameter is applicable:
50 EIDE EIDE/ATAPI support is enabled. 51 EIDE EIDE/ATAPI support is enabled.
51 EVM Extended Verification Module 52 EVM Extended Verification Module
52 FB The frame buffer device is enabled. 53 FB The frame buffer device is enabled.
54 FTRACE Function tracing enabled.
53 GCOV GCOV profiling is enabled. 55 GCOV GCOV profiling is enabled.
54 HW Appropriate hardware is enabled. 56 HW Appropriate hardware is enabled.
55 IA-64 IA-64 architecture is enabled. 57 IA-64 IA-64 architecture is enabled.
@@ -70,6 +72,7 @@ parameter is applicable:
70 Documentation/m68k/kernel-options.txt. 72 Documentation/m68k/kernel-options.txt.
71 MCA MCA bus support is enabled. 73 MCA MCA bus support is enabled.
72 MDA MDA console support is enabled. 74 MDA MDA console support is enabled.
75 MIPS MIPS architecture is enabled.
73 MOUSE Appropriate mouse support is enabled. 76 MOUSE Appropriate mouse support is enabled.
74 MSI Message Signaled Interrupts (PCI). 77 MSI Message Signaled Interrupts (PCI).
75 MTD MTD (Memory Technology Device) support is enabled. 78 MTD MTD (Memory Technology Device) support is enabled.
@@ -101,7 +104,6 @@ parameter is applicable:
101 SPARC Sparc architecture is enabled. 104 SPARC Sparc architecture is enabled.
102 SWSUSP Software suspend (hibernation) is enabled. 105 SWSUSP Software suspend (hibernation) is enabled.
103 SUSPEND System suspend states are enabled. 106 SUSPEND System suspend states are enabled.
104 FTRACE Function tracing enabled.
105 TPM TPM drivers are enabled. 107 TPM TPM drivers are enabled.
106 TS Appropriate touchscreen support is enabled. 108 TS Appropriate touchscreen support is enabled.
107 UMS USB Mass Storage support is enabled. 109 UMS USB Mass Storage support is enabled.
@@ -116,7 +118,7 @@ parameter is applicable:
116 X86-64 X86-64 architecture is enabled. 118 X86-64 X86-64 architecture is enabled.
117 More X86-64 boot options can be found in 119 More X86-64 boot options can be found in
118 Documentation/x86/x86_64/boot-options.txt . 120 Documentation/x86/x86_64/boot-options.txt .
119 X86 Either 32bit or 64bit x86 (same as X86-32+X86-64) 121 X86 Either 32-bit or 64-bit x86 (same as X86-32+X86-64)
120 XEN Xen support is enabled 122 XEN Xen support is enabled
121 123
122In addition, the following text indicates that the option: 124In addition, the following text indicates that the option:
@@ -377,7 +379,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
377 atkbd.softrepeat= [HW] 379 atkbd.softrepeat= [HW]
378 Use software keyboard repeat 380 Use software keyboard repeat
379 381
380 autotest [IA64] 382 autotest [IA-64]
381 383
382 baycom_epp= [HW,AX25] 384 baycom_epp= [HW,AX25]
383 Format: <io>,<mode> 385 Format: <io>,<mode>
@@ -682,8 +684,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
682 uart[8250],mmio32,<addr>[,options] 684 uart[8250],mmio32,<addr>[,options]
683 Start an early, polled-mode console on the 8250/16550 685 Start an early, polled-mode console on the 8250/16550
684 UART at the specified I/O port or MMIO address. 686 UART at the specified I/O port or MMIO address.
685 MMIO inter-register address stride is either 8bit (mmio) 687 MMIO inter-register address stride is either 8-bit
686 or 32bit (mmio32). 688 (mmio) or 32-bit (mmio32).
687 The options are the same as for ttyS, above. 689 The options are the same as for ttyS, above.
688 690
689 earlyprintk= [X86,SH,BLACKFIN] 691 earlyprintk= [X86,SH,BLACKFIN]
@@ -726,7 +728,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
726 See Documentation/block/as-iosched.txt and 728 See Documentation/block/as-iosched.txt and
727 Documentation/block/deadline-iosched.txt for details. 729 Documentation/block/deadline-iosched.txt for details.
728 730
729 elfcorehdr= [IA64,PPC,SH,X86] 731 elfcorehdr= [IA-64,PPC,SH,X86]
730 Specifies physical address of start of kernel core 732 Specifies physical address of start of kernel core
731 image elf header. Generally kexec loader will 733 image elf header. Generally kexec loader will
732 pass this option to capture kernel. 734 pass this option to capture kernel.
@@ -797,7 +799,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
797 tracer at boot up. function-list is a comma separated 799 tracer at boot up. function-list is a comma separated
798 list of functions. This list can be changed at run 800 list of functions. This list can be changed at run
799 time by the set_ftrace_filter file in the debugfs 801 time by the set_ftrace_filter file in the debugfs
800 tracing directory. 802 tracing directory.
801 803
802 ftrace_notrace=[function-list] 804 ftrace_notrace=[function-list]
803 [FTRACE] Do not trace the functions specified in 805 [FTRACE] Do not trace the functions specified in
@@ -835,7 +837,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
835 837
836 hashdist= [KNL,NUMA] Large hashes allocated during boot 838 hashdist= [KNL,NUMA] Large hashes allocated during boot
837 are distributed across NUMA nodes. Defaults on 839 are distributed across NUMA nodes. Defaults on
838 for 64bit NUMA, off otherwise. 840 for 64-bit NUMA, off otherwise.
839 Format: 0 | 1 (for off | on) 841 Format: 0 | 1 (for off | on)
840 842
841 hcl= [IA-64] SGI's Hardware Graph compatibility layer 843 hcl= [IA-64] SGI's Hardware Graph compatibility layer
@@ -1004,10 +1006,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1004 DMA. 1006 DMA.
1005 forcedac [x86_64] 1007 forcedac [x86_64]
1006 With this option iommu will not optimize to look 1008 With this option iommu will not optimize to look
1007 for io virtual address below 32 bit forcing dual 1009 for io virtual address below 32-bit forcing dual
1008 address cycle on pci bus for cards supporting greater 1010 address cycle on pci bus for cards supporting greater
1009 than 32 bit addressing. The default is to look 1011 than 32-bit addressing. The default is to look
1010 for translation below 32 bit and if not available 1012 for translation below 32-bit and if not available
1011 then look in the higher range. 1013 then look in the higher range.
1012 strict [Default Off] 1014 strict [Default Off]
1013 With this option on every unmap_single operation will 1015 With this option on every unmap_single operation will
@@ -1023,7 +1025,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1023 off disable Interrupt Remapping 1025 off disable Interrupt Remapping
1024 nosid disable Source ID checking 1026 nosid disable Source ID checking
1025 1027
1026 inttest= [IA64] 1028 inttest= [IA-64]
1027 1029
1028 iomem= Disable strict checking of access to MMIO memory 1030 iomem= Disable strict checking of access to MMIO memory
1029 strict regions from userspace. 1031 strict regions from userspace.
@@ -1040,7 +1042,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1040 nomerge 1042 nomerge
1041 forcesac 1043 forcesac
1042 soft 1044 soft
1043 pt [x86, IA64] 1045 pt [x86, IA-64]
1044 1046
1045 io7= [HW] IO7 for Marvel based alpha systems 1047 io7= [HW] IO7 for Marvel based alpha systems
1046 See comment before marvel_specify_io7 in 1048 See comment before marvel_specify_io7 in
@@ -1171,7 +1173,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1171 1173
1172 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU) 1174 kvm-amd.npt= [KVM,AMD] Disable nested paging (virtualized MMU)
1173 for all guests. 1175 for all guests.
1174 Default is 1 (enabled) if in 64bit or 32bit-PAE mode 1176 Default is 1 (enabled) if in 64-bit or 32-bit PAE mode.
1175 1177
1176 kvm-intel.ept= [KVM,Intel] Disable extended page tables 1178 kvm-intel.ept= [KVM,Intel] Disable extended page tables
1177 (virtualized MMU) support on capable Intel chips. 1179 (virtualized MMU) support on capable Intel chips.
@@ -1208,10 +1210,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1208 libata.dma=0 Disable all PATA and SATA DMA 1210 libata.dma=0 Disable all PATA and SATA DMA
1209 libata.dma=1 PATA and SATA Disk DMA only 1211 libata.dma=1 PATA and SATA Disk DMA only
1210 libata.dma=2 ATAPI (CDROM) DMA only 1212 libata.dma=2 ATAPI (CDROM) DMA only
1211 libata.dma=4 Compact Flash DMA only 1213 libata.dma=4 Compact Flash DMA only
1212 Combinations also work, so libata.dma=3 enables DMA 1214 Combinations also work, so libata.dma=3 enables DMA
1213 for disks and CDROMs, but not CFs. 1215 for disks and CDROMs, but not CFs.
1214 1216
1215 libata.ignore_hpa= [LIBATA] Ignore HPA limit 1217 libata.ignore_hpa= [LIBATA] Ignore HPA limit
1216 libata.ignore_hpa=0 keep BIOS limits (default) 1218 libata.ignore_hpa=0 keep BIOS limits (default)
1217 libata.ignore_hpa=1 ignore limits, using full disk 1219 libata.ignore_hpa=1 ignore limits, using full disk
@@ -1337,7 +1339,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1337 ltpc= [NET] 1339 ltpc= [NET]
1338 Format: <io>,<irq>,<dma> 1340 Format: <io>,<irq>,<dma>
1339 1341
1340 machvec= [IA64] Force the use of a particular machine-vector 1342 machvec= [IA-64] Force the use of a particular machine-vector
1341 (machvec) in a generic kernel. 1343 (machvec) in a generic kernel.
1342 Example: machvec=hpzx1_swiotlb 1344 Example: machvec=hpzx1_swiotlb
1343 1345
@@ -1354,9 +1356,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1354 it is equivalent to "nosmp", which also disables 1356 it is equivalent to "nosmp", which also disables
1355 the IO APIC. 1357 the IO APIC.
1356 1358
1357 max_loop= [LOOP] Maximum number of loopback devices that can 1359 max_loop= [LOOP] The number of loop block devices that get
1358 be mounted 1360 (loop.max_loop) unconditionally pre-created at init time. The default
1359 Format: <1-256> 1361 number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead
1362 of statically allocating a predefined number, loop
1363 devices can be requested on-demand with the
1364 /dev/loop-control interface.
1360 1365
1361 mcatest= [IA-64] 1366 mcatest= [IA-64]
1362 1367
@@ -1740,7 +1745,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1740 1745
1741 nointroute [IA-64] 1746 nointroute [IA-64]
1742 1747
1743 nojitter [IA64] Disables jitter checking for ITC timers. 1748 nojitter [IA-64] Disables jitter checking for ITC timers.
1744 1749
1745 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver 1750 no-kvmclock [X86,KVM] Disable paravirtualized KVM clock driver
1746 1751
@@ -1806,7 +1811,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
1806 1811
1807 nox2apic [X86-64,APIC] Do not enable x2APIC mode. 1812 nox2apic [X86-64,APIC] Do not enable x2APIC mode.
1808 1813
1809 nptcg= [IA64] Override max number of concurrent global TLB 1814 nptcg= [IA-64] Override max number of concurrent global TLB
1810 purges which is reported from either PAL_VM_SUMMARY or 1815 purges which is reported from either PAL_VM_SUMMARY or
1811 SAL PALO. 1816 SAL PALO.
1812 1817
@@ -2083,13 +2088,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2083 Format: { parport<nr> | timid | 0 } 2088 Format: { parport<nr> | timid | 0 }
2084 See also Documentation/parport.txt. 2089 See also Documentation/parport.txt.
2085 2090
2086 pmtmr= [X86] Manual setup of pmtmr I/O Port. 2091 pmtmr= [X86] Manual setup of pmtmr I/O Port.
2087 Override pmtimer IOPort with a hex value. 2092 Override pmtimer IOPort with a hex value.
2088 e.g. pmtmr=0x508 2093 e.g. pmtmr=0x508
2089 2094
2090 pnp.debug [PNP] 2095 pnp.debug=1 [PNP]
2091 Enable PNP debug messages. This depends on the 2096 Enable PNP debug messages (depends on the
2092 CONFIG_PNP_DEBUG_MESSAGES option. 2097 CONFIG_PNP_DEBUG_MESSAGES option). Change at run-time
2098 via /sys/module/pnp/parameters/debug. We always show
2099 current resource usage; turning this on also shows
2100 possible settings and some assignment information.
2093 2101
2094 pnpacpi= [ACPI] 2102 pnpacpi= [ACPI]
2095 { off } 2103 { off }
@@ -2641,6 +2649,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2641 medium is write-protected). 2649 medium is write-protected).
2642 Example: quirks=0419:aaf5:rl,0421:0433:rc 2650 Example: quirks=0419:aaf5:rl,0421:0433:rc
2643 2651
2652 user_debug= [KNL,ARM]
2653 Format: <int>
2654 See arch/arm/Kconfig.debug help text.
2655 1 - undefined instruction events
2656 2 - system calls
2657 4 - invalid data aborts
2658 8 - SIGSEGV faults
2659 16 - SIGBUS faults
2660 Example: user_debug=31
2661
2644 userpte= 2662 userpte=
2645 [X86] Flags controlling user PTE allocations. 2663 [X86] Flags controlling user PTE allocations.
2646 2664
@@ -2686,6 +2704,28 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
2686 vmpoff= [KNL,S390] Perform z/VM CP command after power off. 2704 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
2687 Format: <command> 2705 Format: <command>
2688 2706
2707 vsyscall= [X86-64]
2708 Controls the behavior of vsyscalls (i.e. calls to
2709 fixed addresses of 0xffffffffff600x00 from legacy
2710 code). Most statically-linked binaries and older
2711 versions of glibc use these calls. Because these
2712 functions are at fixed addresses, they make nice
2713 targets for exploits that can control RIP.
2714
2715 emulate Vsyscalls turn into traps and are emulated
2716 reasonably safely.
2717
2718 native [default] Vsyscalls are native syscall
2719 instructions.
2720 This is a little bit faster than trapping
2721 and makes a few dynamic recompilers work
2722 better than they would in emulation mode.
2723 It also makes exploits much easier to write.
2724
2725 none Vsyscalls don't work at all. This makes
2726 them quite hard to use for exploits but
2727 might break your system.
2728
2689 vt.cur_default= [VT] Default cursor shape. 2729 vt.cur_default= [VT] Default cursor shape.
2690 Format: 0xCCBBAA, where AA, BB, and CC are the same as 2730 Format: 0xCCBBAA, where AA, BB, and CC are the same as
2691 the parameters of the <Esc>[?A;B;Cc escape sequence; 2731 the parameters of the <Esc>[?A;B;Cc escape sequence;