| kernel-parameters.txt (c49a0a80137c7ca7d6ced4c812c9e07a949f6f24) | kernel-parameters.txt (000d388ed3bbed745f366ce71b2bb7c2ee70f449) |
|---|---|
| 1 acpi= [HW,ACPI,X86,ARM64] 2 Advanced Configuration and Power Interface 3 Format: { force | on | off | strict | noirq | rsdt | 4 copy_dsdt } 5 force -- enable ACPI if default was off 6 on -- enable ACPI but allow fallback to DT [arm64] 7 off -- disable ACPI if default was on 8 noirq -- do not use ACPI for IRQ routing 9 strict -- Be less tolerant of platforms that are not 10 strictly ACPI specification compliant. 11 rsdt -- prefer RSDT over (default) XSDT 12 copy_dsdt -- copy DSDT to memory 13 For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force" 14 are available 15 | 1 acpi= [HW,ACPI,X86,ARM64] 2 Advanced Configuration and Power Interface 3 Format: { force | on | off | strict | noirq | rsdt | 4 copy_dsdt } 5 force -- enable ACPI if default was off 6 on -- enable ACPI but allow fallback to DT [arm64] 7 off -- disable ACPI if default was on 8 noirq -- do not use ACPI for IRQ routing 9 strict -- Be less tolerant of platforms that are not 10 strictly ACPI specification compliant. 11 rsdt -- prefer RSDT over (default) XSDT 12 copy_dsdt -- copy DSDT to memory 13 For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force" 14 are available 15 |
| 16 See also Documentation/power/runtime_pm.rst, pci=noacpi | 16 See also Documentation/power/runtime_pm.txt, pci=noacpi |
| 17 18 acpi_apic_instance= [ACPI, IOAPIC] 19 Format: <int> 20 2: use 2nd APIC table, if available 21 1,0: use 1st APIC table 22 default: 0 23 24 acpi_backlight= [HW,ACPI] --- 23 unchanged lines hidden (view full) --- 48 CONFIG_ACPI_DEBUG must be enabled to produce any ACPI 49 debug output. Bits in debug_layer correspond to a 50 _COMPONENT in an ACPI source file, e.g., 51 #define _COMPONENT ACPI_PCI_COMPONENT 52 Bits in debug_level correspond to a level in 53 ACPI_DEBUG_PRINT statements, e.g., 54 ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... 55 The debug_level mask defaults to "info". See | 17 18 acpi_apic_instance= [ACPI, IOAPIC] 19 Format: <int> 20 2: use 2nd APIC table, if available 21 1,0: use 1st APIC table 22 default: 0 23 24 acpi_backlight= [HW,ACPI] --- 23 unchanged lines hidden (view full) --- 48 CONFIG_ACPI_DEBUG must be enabled to produce any ACPI 49 debug output. Bits in debug_layer correspond to a 50 _COMPONENT in an ACPI source file, e.g., 51 #define _COMPONENT ACPI_PCI_COMPONENT 52 Bits in debug_level correspond to a level in 53 ACPI_DEBUG_PRINT statements, e.g., 54 ACPI_DEBUG_PRINT((ACPI_DB_INFO, ... 55 The debug_level mask defaults to "info". See |
| 56 Documentation/firmware-guide/acpi/debug.rst for more information about | 56 Documentation/acpi/debug.txt for more information about |
| 57 debug layers and levels. 58 59 Enable processor driver info messages: 60 acpi.debug_layer=0x20000000 61 Enable PCI/PCI interrupt routing info messages: 62 acpi.debug_layer=0x400000 63 Enable AML "Debug" output, i.e., stores to the Debug 64 object while interpreting AML: --- 153 unchanged lines hidden (view full) --- 218 219 acpi_skip_timer_override [HW,ACPI] 220 Recognize and ignore IRQ0/pin2 Interrupt Override. 221 For broken nForce2 BIOS resulting in XT-PIC timer. 222 223 acpi_sleep= [HW,ACPI] Sleep options 224 Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, 225 old_ordering, nonvs, sci_force_enable, nobl } | 57 debug layers and levels. 58 59 Enable processor driver info messages: 60 acpi.debug_layer=0x20000000 61 Enable PCI/PCI interrupt routing info messages: 62 acpi.debug_layer=0x400000 63 Enable AML "Debug" output, i.e., stores to the Debug 64 object while interpreting AML: --- 153 unchanged lines hidden (view full) --- 218 219 acpi_skip_timer_override [HW,ACPI] 220 Recognize and ignore IRQ0/pin2 Interrupt Override. 221 For broken nForce2 BIOS resulting in XT-PIC timer. 222 223 acpi_sleep= [HW,ACPI] Sleep options 224 Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, 225 old_ordering, nonvs, sci_force_enable, nobl } |
| 226 See Documentation/power/video.rst for information on | 226 See Documentation/power/video.txt for information on |
| 227 s3_bios and s3_mode. 228 s3_beep is for debugging; it makes the PC's speaker beep 229 as soon as the kernel's real-mode entry point is called. 230 s4_nohwsig prevents ACPI hardware signature from being 231 used during resume from hibernation. 232 old_ordering causes the ACPI 1.0 ordering of the _PTS 233 control method, with respect to putting devices into 234 low power states, to be enforced (the ACPI 2.0 ordering --- 190 unchanged lines hidden (view full) --- 425 426 baycom_ser_hdx= [HW,AX25] 427 BayCom Serial Port AX.25 Modem (Half Duplex Mode) 428 Format: <io>,<irq>,<mode> 429 See header of drivers/net/hamradio/baycom_ser_hdx.c. 430 431 blkdevparts= Manual partition parsing of block device(s) for 432 embedded devices based on command line input. | 227 s3_bios and s3_mode. 228 s3_beep is for debugging; it makes the PC's speaker beep 229 as soon as the kernel's real-mode entry point is called. 230 s4_nohwsig prevents ACPI hardware signature from being 231 used during resume from hibernation. 232 old_ordering causes the ACPI 1.0 ordering of the _PTS 233 control method, with respect to putting devices into 234 low power states, to be enforced (the ACPI 2.0 ordering --- 190 unchanged lines hidden (view full) --- 425 426 baycom_ser_hdx= [HW,AX25] 427 BayCom Serial Port AX.25 Modem (Half Duplex Mode) 428 Format: <io>,<irq>,<mode> 429 See header of drivers/net/hamradio/baycom_ser_hdx.c. 430 431 blkdevparts= Manual partition parsing of block device(s) for 432 embedded devices based on command line input. |
| 433 See Documentation/block/cmdline-partition.rst | 433 See Documentation/block/cmdline-partition.txt |
| 434 435 boot_delay= Milliseconds to delay each printk during boot. 436 Values larger than 10 seconds (10000) are changed to 437 no delay (0). 438 Format: integer 439 440 bootmem_debug [KNL] Enable bootmem allocator debug messages. 441 --- 31 unchanged lines hidden (view full) --- 473 474 cca= [MIPS] Override the kernel pages' cache coherency 475 algorithm. Accepted values range from 0 to 7 476 inclusive. See arch/mips/include/asm/pgtable-bits.h 477 for platform specific values (SB1, Loongson3 and 478 others). 479 480 ccw_timeout_log [S390] | 434 435 boot_delay= Milliseconds to delay each printk during boot. 436 Values larger than 10 seconds (10000) are changed to 437 no delay (0). 438 Format: integer 439 440 bootmem_debug [KNL] Enable bootmem allocator debug messages. 441 --- 31 unchanged lines hidden (view full) --- 473 474 cca= [MIPS] Override the kernel pages' cache coherency 475 algorithm. Accepted values range from 0 to 7 476 inclusive. See arch/mips/include/asm/pgtable-bits.h 477 for platform specific values (SB1, Loongson3 and 478 others). 479 480 ccw_timeout_log [S390] |
| 481 See Documentation/s390/common_io.rst for details. | 481 See Documentation/s390/CommonIO for details. |
| 482 483 cgroup_disable= [KNL] Disable a particular controller 484 Format: {name of the controller(s) to disable} 485 The effects of cgroup_disable=foo are: 486 - foo isn't auto-mounted if you mount all cgroups in 487 a single hierarchy 488 - foo isn't visible as an individually mountable 489 subsystem --- 21 unchanged lines hidden (view full) --- 511 0 -- check protection applied by kernel (includes 512 any implied execute protection). 513 1 -- check protection requested by application. 514 Default value is set via a kernel config option. 515 Value can be changed at runtime via 516 /selinux/checkreqprot. 517 518 cio_ignore= [S390] | 482 483 cgroup_disable= [KNL] Disable a particular controller 484 Format: {name of the controller(s) to disable} 485 The effects of cgroup_disable=foo are: 486 - foo isn't auto-mounted if you mount all cgroups in 487 a single hierarchy 488 - foo isn't visible as an individually mountable 489 subsystem --- 21 unchanged lines hidden (view full) --- 511 0 -- check protection applied by kernel (includes 512 any implied execute protection). 513 1 -- check protection requested by application. 514 Default value is set via a kernel config option. 515 Value can be changed at runtime via 516 /selinux/checkreqprot. 517 518 cio_ignore= [S390] |
| 519 See Documentation/s390/common_io.rst for details. | 519 See Documentation/s390/CommonIO for details. |
| 520 clk_ignore_unused 521 [CLK] 522 Prevents the clock framework from automatically gating 523 clocks that have not been explicitly enabled by a Linux 524 device driver but are enabled in hardware at reset or 525 by the bootloader/firmware. Note that this does not 526 force such clocks to be always-on nor does it reserve 527 those clocks in any way. This parameter is useful for --- 175 unchanged lines hidden (view full) --- 703 [KNL] Using kexec, Linux can switch to a 'crash kernel' 704 upon panic. This parameter reserves the physical 705 memory region [offset, offset + size] for that kernel 706 image. If '@offset' is omitted, then a suitable offset 707 is selected automatically. 708 [KNL, x86_64] select a region under 4G first, and 709 fall back to reserve region above 4G when '@offset' 710 hasn't been specified. | 520 clk_ignore_unused 521 [CLK] 522 Prevents the clock framework from automatically gating 523 clocks that have not been explicitly enabled by a Linux 524 device driver but are enabled in hardware at reset or 525 by the bootloader/firmware. Note that this does not 526 force such clocks to be always-on nor does it reserve 527 those clocks in any way. This parameter is useful for --- 175 unchanged lines hidden (view full) --- 703 [KNL] Using kexec, Linux can switch to a 'crash kernel' 704 upon panic. This parameter reserves the physical 705 memory region [offset, offset + size] for that kernel 706 image. If '@offset' is omitted, then a suitable offset 707 is selected automatically. 708 [KNL, x86_64] select a region under 4G first, and 709 fall back to reserve region above 4G when '@offset' 710 hasn't been specified. |
| 711 See Documentation/admin-guide/kdump/kdump.rst for further details. | 711 See Documentation/kdump/kdump.txt for further details. |
| 712 713 crashkernel=range1:size1[,range2:size2,...][@offset] 714 [KNL] Same as above, but depends on the memory 715 in the running system. The syntax of range is 716 start-[end] where start and end are both 717 a memory unit (amount[KMG]). See also | 712 713 crashkernel=range1:size1[,range2:size2,...][@offset] 714 [KNL] Same as above, but depends on the memory 715 in the running system. The syntax of range is 716 start-[end] where start and end are both 717 a memory unit (amount[KMG]). See also |
| 718 Documentation/admin-guide/kdump/kdump.rst for an example. | 718 Documentation/kdump/kdump.txt for an example. |
| 719 720 crashkernel=size[KMG],high 721 [KNL, x86_64] range could be above 4G. Allow kernel 722 to allocate physical memory region from top, so could 723 be above 4G if system have more than 4G ram installed. 724 Otherwise memory region will be allocated below 4G, if 725 available. 726 It will be ignored if crashkernel=X is specified. --- 73 unchanged lines hidden (view full) --- 800 of memory corruptions problems caused by buggy H/W or 801 F/W or by drivers badly programing DMA (basically when 802 memory is written at bus level and the CPU MMU is 803 bypassed) which are not detectable by 804 CONFIG_DEBUG_PAGEALLOC, hence this option will not help 805 tracking down these problems. 806 807 debug_pagealloc= | 719 720 crashkernel=size[KMG],high 721 [KNL, x86_64] range could be above 4G. Allow kernel 722 to allocate physical memory region from top, so could 723 be above 4G if system have more than 4G ram installed. 724 Otherwise memory region will be allocated below 4G, if 725 available. 726 It will be ignored if crashkernel=X is specified. --- 73 unchanged lines hidden (view full) --- 800 of memory corruptions problems caused by buggy H/W or 801 F/W or by drivers badly programing DMA (basically when 802 memory is written at bus level and the CPU MMU is 803 bypassed) which are not detectable by 804 CONFIG_DEBUG_PAGEALLOC, hence this option will not help 805 tracking down these problems. 806 807 debug_pagealloc= |
| 808 [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this parameter 809 enables the feature at boot time. By default, it is 810 disabled and the system will work mostly the same as a 811 kernel built without CONFIG_DEBUG_PAGEALLOC. | 808 [KNL] When CONFIG_DEBUG_PAGEALLOC is set, this 809 parameter enables the feature at boot time. In 810 default, it is disabled. We can avoid allocating huge 811 chunk of memory for debug pagealloc if we don't enable 812 it at boot time and the system will work mostly same 813 with the kernel built without CONFIG_DEBUG_PAGEALLOC. |
| 812 on: enable the feature 813 814 debugpat [X86] Enable PAT debugging 815 816 decnet.addr= [HW,NET] 817 Format: <area>[,<node>] 818 See also Documentation/networking/decnet.txt. 819 --- 105 unchanged lines hidden (view full) --- 925 panels may send no or incorrect EDID data sets. 926 This parameter allows to specify an EDID data sets 927 in the /lib/firmware directory that are used instead. 928 Generic built-in EDID data sets are used, if one of 929 edid/1024x768.bin, edid/1280x1024.bin, 930 edid/1680x1050.bin, or edid/1920x1080.bin is given 931 and no file with the same name exists. Details and 932 instructions how to build your own EDID data are | 814 on: enable the feature 815 816 debugpat [X86] Enable PAT debugging 817 818 decnet.addr= [HW,NET] 819 Format: <area>[,<node>] 820 See also Documentation/networking/decnet.txt. 821 --- 105 unchanged lines hidden (view full) --- 927 panels may send no or incorrect EDID data sets. 928 This parameter allows to specify an EDID data sets 929 in the /lib/firmware directory that are used instead. 930 Generic built-in EDID data sets are used, if one of 931 edid/1024x768.bin, edid/1280x1024.bin, 932 edid/1680x1050.bin, or edid/1920x1080.bin is given 933 and no file with the same name exists. Details and 934 instructions how to build your own EDID data are |
| 933 available in Documentation/driver-api/edid.rst. An EDID | 935 available in Documentation/EDID/HOWTO.txt. An EDID |
| 934 data set will only be used for a particular connector, 935 if its name and a colon are prepended to the EDID 936 name. Each connector may use a unique EDID data 937 set by separating the files with a comma. An EDID 938 data set with no connector name will be used for 939 any connectors not explicitly specified. 940 941 dscc4.setup= [NET] --- 14 unchanged lines hidden (view full) --- 956 957 dyndbg[="val"] [KNL,DYNAMIC_DEBUG] 958 module.dyndbg[="val"] 959 Enable debug messages at boot time. See 960 Documentation/admin-guide/dynamic-debug-howto.rst 961 for details. 962 963 nompx [X86] Disables Intel Memory Protection Extensions. | 936 data set will only be used for a particular connector, 937 if its name and a colon are prepended to the EDID 938 name. Each connector may use a unique EDID data 939 set by separating the files with a comma. An EDID 940 data set with no connector name will be used for 941 any connectors not explicitly specified. 942 943 dscc4.setup= [NET] --- 14 unchanged lines hidden (view full) --- 958 959 dyndbg[="val"] [KNL,DYNAMIC_DEBUG] 960 module.dyndbg[="val"] 961 Enable debug messages at boot time. See 962 Documentation/admin-guide/dynamic-debug-howto.rst 963 for details. 964 965 nompx [X86] Disables Intel Memory Protection Extensions. |
| 964 See Documentation/x86/intel_mpx.rst for more | 966 See Documentation/x86/intel_mpx.txt for more |
| 965 information about the feature. 966 967 nopku [X86] Disable Memory Protection Keys CPU feature found 968 in some Intel CPUs. 969 970 module.async_probe [KNL] 971 Enable asynchronous probe on this module. 972 --- 209 unchanged lines hidden (view full) --- 1182 related feature. For example, you can do debugging of 1183 Address Range Mirroring feature even if your box 1184 doesn't support it. 1185 1186 efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT 1187 that is to be dynamically loaded by Linux. If there are 1188 multiple variables with the same name but with different 1189 vendor GUIDs, all of them will be loaded. See | 967 information about the feature. 968 969 nopku [X86] Disable Memory Protection Keys CPU feature found 970 in some Intel CPUs. 971 972 module.async_probe [KNL] 973 Enable asynchronous probe on this module. 974 --- 209 unchanged lines hidden (view full) --- 1184 related feature. For example, you can do debugging of 1185 Address Range Mirroring feature even if your box 1186 doesn't support it. 1187 1188 efivar_ssdt= [EFI; X86] Name of an EFI variable that contains an SSDT 1189 that is to be dynamically loaded by Linux. If there are 1190 multiple variables with the same name but with different 1191 vendor GUIDs, all of them will be loaded. See |
| 1190 Documentation/admin-guide/acpi/ssdt-overlays.rst for details. | 1192 Documentation/acpi/ssdt-overlays.txt for details. |
| 1191 1192 1193 eisa_irq_edge= [PARISC,HW] 1194 See header of drivers/parisc/eisa.c. 1195 1196 elanfreq= [X86-32] 1197 See comment before function elanfreq_setup() in 1198 arch/x86/kernel/cpu/cpufreq/elanfreq.c. 1199 1200 elevator= [IOSCHED] 1201 Format: { "mq-deadline" | "kyber" | "bfq" } | 1193 1194 1195 eisa_irq_edge= [PARISC,HW] 1196 See header of drivers/parisc/eisa.c. 1197 1198 elanfreq= [X86-32] 1199 See comment before function elanfreq_setup() in 1200 arch/x86/kernel/cpu/cpufreq/elanfreq.c. 1201 1202 elevator= [IOSCHED] 1203 Format: { "mq-deadline" | "kyber" | "bfq" } |
| 1202 See Documentation/block/deadline-iosched.rst, 1203 Documentation/block/kyber-iosched.rst and 1204 Documentation/block/bfq-iosched.rst for details. | 1204 See Documentation/block/deadline-iosched.txt, 1205 Documentation/block/kyber-iosched.txt and 1206 Documentation/block/bfq-iosched.txt for details. |
| 1205 1206 elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] 1207 Specifies physical address of start of kernel core 1208 image elf header and optionally the size. Generally 1209 kexec loader will pass this option to capture kernel. | 1207 1208 elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] 1209 Specifies physical address of start of kernel core 1210 image elf header and optionally the size. Generally 1211 kexec loader will pass this option to capture kernel. |
| 1210 See Documentation/admin-guide/kdump/kdump.rst for details. | 1212 See Documentation/kdump/kdump.txt for details. |
| 1211 1212 enable_mtrr_cleanup [X86] 1213 The kernel tries to adjust MTRR layout from continuous 1214 to discrete, to make X server driver able to add WB 1215 entry later. This parameter enables that. 1216 1217 enable_timer_pin_1 [X86] 1218 Enable PIN 1 of APIC timer --- 25 unchanged lines hidden (view full) --- 1244 failslab= 1245 fail_page_alloc= 1246 fail_make_request=[KNL] 1247 General fault injection mechanism. 1248 Format: <interval>,<probability>,<space>,<times> 1249 See also Documentation/fault-injection/. 1250 1251 floppy= [HW] | 1213 1214 enable_mtrr_cleanup [X86] 1215 The kernel tries to adjust MTRR layout from continuous 1216 to discrete, to make X server driver able to add WB 1217 entry later. This parameter enables that. 1218 1219 enable_timer_pin_1 [X86] 1220 Enable PIN 1 of APIC timer --- 25 unchanged lines hidden (view full) --- 1246 failslab= 1247 fail_page_alloc= 1248 fail_make_request=[KNL] 1249 General fault injection mechanism. 1250 Format: <interval>,<probability>,<space>,<times> 1251 See also Documentation/fault-injection/. 1252 1253 floppy= [HW] |
| 1252 See Documentation/admin-guide/blockdev/floppy.rst. | 1254 See Documentation/blockdev/floppy.txt. |
| 1253 1254 force_pal_cache_flush 1255 [IA-64] Avoid check_sal_cache_flush which may hang on 1256 buggy SAL_CACHE_FLUSH implementations. Using this 1257 parameter will force ia64_sal_cache_flush to call 1258 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. 1259 1260 forcepae [X86-32] --- 120 unchanged lines hidden (view full) --- 1381 size of <nn>. This works even on boxes that have no 1382 highmem otherwise. This also works to reduce highmem 1383 size on bigger boxes. 1384 1385 highres= [KNL] Enable/disable high resolution timer mode. 1386 Valid parameters: "on", "off" 1387 Default: "on" 1388 | 1255 1256 force_pal_cache_flush 1257 [IA-64] Avoid check_sal_cache_flush which may hang on 1258 buggy SAL_CACHE_FLUSH implementations. Using this 1259 parameter will force ia64_sal_cache_flush to call 1260 ia64_pal_cache_flush instead of SAL_CACHE_FLUSH. 1261 1262 forcepae [X86-32] --- 120 unchanged lines hidden (view full) --- 1383 size of <nn>. This works even on boxes that have no 1384 highmem otherwise. This also works to reduce highmem 1385 size on bigger boxes. 1386 1387 highres= [KNL] Enable/disable high resolution timer mode. 1388 Valid parameters: "on", "off" 1389 Default: "on" 1390 |
| 1391 hisax= [HW,ISDN] 1392 See Documentation/isdn/README.HiSax. 1393 |
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| 1389 hlt [BUGS=ARM,SH] 1390 1391 hpet= [X86-32,HPET] option to control HPET usage 1392 Format: { enable (default) | disable | force | 1393 verbose } 1394 disable: disable HPET and use PIT instead 1395 force: allow force enabled of undocumented chips (ICH4, 1396 VIA, nVidia) --- 100 unchanged lines hidden (view full) --- 1497 1498 icn= [HW,ISDN] 1499 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] 1500 1501 ide-core.nodma= [HW] (E)IDE subsystem 1502 Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc 1503 .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr 1504 .cdrom .chs .ignore_cable are additional options | 1394 hlt [BUGS=ARM,SH] 1395 1396 hpet= [X86-32,HPET] option to control HPET usage 1397 Format: { enable (default) | disable | force | 1398 verbose } 1399 disable: disable HPET and use PIT instead 1400 force: allow force enabled of undocumented chips (ICH4, 1401 VIA, nVidia) --- 100 unchanged lines hidden (view full) --- 1502 1503 icn= [HW,ISDN] 1504 Format: <io>[,<membase>[,<icn_id>[,<icn_id2>]]] 1505 1506 ide-core.nodma= [HW] (E)IDE subsystem 1507 Format: =0.0 to prevent dma on hda, =0.1 hdb =1.0 hdc 1508 .vlb_clock .pci_clock .noflush .nohpa .noprobe .nowerr 1509 .cdrom .chs .ignore_cable are additional options |
| 1505 See Documentation/ide/ide.rst. | 1510 See Documentation/ide/ide.txt. |
| 1506 1507 ide-generic.probe-mask= [HW] (E)IDE subsystem 1508 Format: <int> 1509 Probe mask for legacy ISA IDE ports. Depending on 1510 platform up to 6 ports are supported, enabled by 1511 setting corresponding bits in the mask to 1. The 1512 default value is 0x0, which has a special meaning. 1513 On systems that have PCI, it triggers scanning the --- 149 unchanged lines hidden (view full) --- 1663 startup. 1664 1665 initcall_blacklist= [KNL] Do not execute a comma-separated list of 1666 initcall functions. Useful for debugging built-in 1667 modules and initcalls. 1668 1669 initrd= [BOOT] Specify the location of the initial ramdisk 1670 | 1511 1512 ide-generic.probe-mask= [HW] (E)IDE subsystem 1513 Format: <int> 1514 Probe mask for legacy ISA IDE ports. Depending on 1515 platform up to 6 ports are supported, enabled by 1516 setting corresponding bits in the mask to 1. The 1517 default value is 0x0, which has a special meaning. 1518 On systems that have PCI, it triggers scanning the --- 149 unchanged lines hidden (view full) --- 1668 startup. 1669 1670 initcall_blacklist= [KNL] Do not execute a comma-separated list of 1671 initcall functions. Useful for debugging built-in 1672 modules and initcalls. 1673 1674 initrd= [BOOT] Specify the location of the initial ramdisk 1675 |
| 1671 init_on_alloc= [MM] Fill newly allocated pages and heap objects with 1672 zeroes. 1673 Format: 0 | 1 1674 Default set by CONFIG_INIT_ON_ALLOC_DEFAULT_ON. 1675 1676 init_on_free= [MM] Fill freed pages and heap objects with zeroes. 1677 Format: 0 | 1 1678 Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON. 1679 | |
| 1680 init_pkru= [x86] Specify the default memory protection keys rights 1681 register contents for all processes. 0x55555554 by 1682 default (disallow access to all but pkey 0). Can 1683 override in debugfs after boot. 1684 1685 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver 1686 Format: <irq> 1687 --- 318 unchanged lines hidden (view full) --- 2006 Ethernet adapter MAC address. 2007 2008 kmemleak= [KNL] Boot-time kmemleak enable/disable 2009 Valid arguments: on, off 2010 Default: on 2011 Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, 2012 the default is off. 2013 | 1676 init_pkru= [x86] Specify the default memory protection keys rights 1677 register contents for all processes. 0x55555554 by 1678 default (disallow access to all but pkey 0). Can 1679 override in debugfs after boot. 1680 1681 inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver 1682 Format: <irq> 1683 --- 318 unchanged lines hidden (view full) --- 2002 Ethernet adapter MAC address. 2003 2004 kmemleak= [KNL] Boot-time kmemleak enable/disable 2005 Valid arguments: on, off 2006 Default: on 2007 Built with CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, 2008 the default is off. 2009 |
| 2014 kprobe_event=[probe-list] 2015 [FTRACE] Add kprobe events and enable at boot time. 2016 The probe-list is a semicolon delimited list of probe 2017 definitions. Each definition is same as kprobe_events 2018 interface, but the parameters are comma delimited. 2019 For example, to add a kprobe event on vfs_read with 2020 arg1 and arg2, add to the command line; 2021 2022 kprobe_event=p,vfs_read,$arg1,$arg2 2023 2024 See also Documentation/trace/kprobetrace.rst "Kernel 2025 Boot Parameter" section. 2026 | |
| 2027 kpti= [ARM64] Control page table isolation of user 2028 and kernel address spaces. 2029 Default: enabled on cores which need mitigation. 2030 0: force disabled 2031 1: force enabled 2032 2033 kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. 2034 Default is 0 (don't ignore, but inject #GP) --- 207 unchanged lines hidden (view full) --- 2242 * disable: Disable this device. 2243 2244 If there are multiple matching configurations changing 2245 the same attribute, the last one is used. 2246 2247 memblock=debug [KNL] Enable memblock debug messages. 2248 2249 load_ramdisk= [RAM] List of ramdisks to load from floppy | 2010 kpti= [ARM64] Control page table isolation of user 2011 and kernel address spaces. 2012 Default: enabled on cores which need mitigation. 2013 0: force disabled 2014 1: force enabled 2015 2016 kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs. 2017 Default is 0 (don't ignore, but inject #GP) --- 207 unchanged lines hidden (view full) --- 2225 * disable: Disable this device. 2226 2227 If there are multiple matching configurations changing 2228 the same attribute, the last one is used. 2229 2230 memblock=debug [KNL] Enable memblock debug messages. 2231 2232 load_ramdisk= [RAM] List of ramdisks to load from floppy |
| 2250 See Documentation/admin-guide/blockdev/ramdisk.rst. | 2233 See Documentation/blockdev/ramdisk.txt. |
| 2251 2252 lockd.nlm_grace_period=P [NFS] Assign grace period. 2253 Format: <integer> 2254 2255 lockd.nlm_tcpport=N [NFS] Assign TCP port. 2256 Format: <integer> 2257 2258 lockd.nlm_timeout=T [NFS] Assign timeout value. 2259 Format: <integer> 2260 2261 lockd.nlm_udpport=M [NFS] Assign UDP port. 2262 Format: <integer> 2263 | 2234 2235 lockd.nlm_grace_period=P [NFS] Assign grace period. 2236 Format: <integer> 2237 2238 lockd.nlm_tcpport=N [NFS] Assign TCP port. 2239 Format: <integer> 2240 2241 lockd.nlm_timeout=T [NFS] Assign timeout value. 2242 Format: <integer> 2243 2244 lockd.nlm_udpport=M [NFS] Assign UDP port. 2245 Format: <integer> 2246 |
| 2247 lockdown= [SECURITY] 2248 { integrity | confidentiality } 2249 Enable the kernel lockdown feature. If set to 2250 integrity, kernel features that allow userland to 2251 modify the running kernel are disabled. If set to 2252 confidentiality, kernel features that allow userland 2253 to extract confidential information from the kernel 2254 are also disabled. 2255 |
|
| 2264 locktorture.nreaders_stress= [KNL] 2265 Set the number of locking read-acquisition kthreads. 2266 Defaults to being automatically set based on the 2267 number of online CPUs. 2268 2269 locktorture.nwriters_stress= [KNL] 2270 Set the number of locking write-acquisition kthreads. 2271 --- 123 unchanged lines hidden (view full) --- 2395 (loop.max_loop) unconditionally pre-created at init time. The default 2396 number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead 2397 of statically allocating a predefined number, loop 2398 devices can be requested on-demand with the 2399 /dev/loop-control interface. 2400 2401 mce [X86-32] Machine Check Exception 2402 | 2256 locktorture.nreaders_stress= [KNL] 2257 Set the number of locking read-acquisition kthreads. 2258 Defaults to being automatically set based on the 2259 number of online CPUs. 2260 2261 locktorture.nwriters_stress= [KNL] 2262 Set the number of locking write-acquisition kthreads. 2263 --- 123 unchanged lines hidden (view full) --- 2387 (loop.max_loop) unconditionally pre-created at init time. The default 2388 number is configured by BLK_DEV_LOOP_MIN_COUNT. Instead 2389 of statically allocating a predefined number, loop 2390 devices can be requested on-demand with the 2391 /dev/loop-control interface. 2392 2393 mce [X86-32] Machine Check Exception 2394 |
| 2403 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.rst | 2395 mce=option [X86-64] See Documentation/x86/x86_64/boot-options.txt |
| 2404 2405 md= [HW] RAID subsystems devices and level 2406 See Documentation/admin-guide/md.rst. 2407 2408 mdacon= [MDA] 2409 Format: <first>,<last> 2410 Specifies range of consoles to be captured by the MDA. 2411 --- 39 unchanged lines hidden (view full) --- 2451 per-device physically contiguous DMA buffers. 2452 2453 memhp_default_state=online/offline 2454 [KNL] Set the initial state for the memory hotplug 2455 onlining policy. If not specified, the default value is 2456 set according to the 2457 CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config 2458 option. | 2396 2397 md= [HW] RAID subsystems devices and level 2398 See Documentation/admin-guide/md.rst. 2399 2400 mdacon= [MDA] 2401 Format: <first>,<last> 2402 Specifies range of consoles to be captured by the MDA. 2403 --- 39 unchanged lines hidden (view full) --- 2443 per-device physically contiguous DMA buffers. 2444 2445 memhp_default_state=online/offline 2446 [KNL] Set the initial state for the memory hotplug 2447 onlining policy. If not specified, the default value is 2448 set according to the 2449 CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE kernel config 2450 option. |
| 2459 See Documentation/admin-guide/mm/memory-hotplug.rst. | 2451 See Documentation/memory-hotplug.txt. |
| 2460 2461 memmap=exactmap [KNL,X86] Enable setting of an exact 2462 E820 memory map, as specified by the user. 2463 Such memmap=exactmap lines can be constructed based on 2464 BIOS output or other requirements. See the memmap=nn@ss 2465 option description. 2466 2467 memmap=nn[KMG]@ss[KMG] --- 72 unchanged lines hidden (view full) --- 2540 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control 2541 Valid arguments: on, off 2542 Default (depends on kernel configuration option): 2543 on (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y) 2544 off (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n) 2545 mem_encrypt=on: Activate SME 2546 mem_encrypt=off: Do not activate SME 2547 | 2452 2453 memmap=exactmap [KNL,X86] Enable setting of an exact 2454 E820 memory map, as specified by the user. 2455 Such memmap=exactmap lines can be constructed based on 2456 BIOS output or other requirements. See the memmap=nn@ss 2457 option description. 2458 2459 memmap=nn[KMG]@ss[KMG] --- 72 unchanged lines hidden (view full) --- 2532 mem_encrypt= [X86-64] AMD Secure Memory Encryption (SME) control 2533 Valid arguments: on, off 2534 Default (depends on kernel configuration option): 2535 on (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=y) 2536 off (CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n) 2537 mem_encrypt=on: Activate SME 2538 mem_encrypt=off: Do not activate SME 2539 |
| 2548 Refer to Documentation/virt/kvm/amd-memory-encryption.rst | 2540 Refer to Documentation/x86/amd-memory-encryption.txt |
| 2549 for details on when memory encryption can be activated. 2550 2551 mem_sleep_default= [SUSPEND] Default system suspend mode: 2552 s2idle - Suspend-To-Idle 2553 shallow - Power-On Suspend or equivalent (if supported) 2554 deep - Suspend-To-RAM or equivalent (if supported) 2555 See Documentation/admin-guide/pm/sleep-states.rst. 2556 --- 42 unchanged lines hidden (view full) --- 2599 aggregation of existing arch-specific options. 2600 2601 off 2602 Disable all optional CPU mitigations. This 2603 improves system performance, but it may also 2604 expose users to several CPU vulnerabilities. 2605 Equivalent to: nopti [X86,PPC] 2606 kpti=0 [ARM64] | 2541 for details on when memory encryption can be activated. 2542 2543 mem_sleep_default= [SUSPEND] Default system suspend mode: 2544 s2idle - Suspend-To-Idle 2545 shallow - Power-On Suspend or equivalent (if supported) 2546 deep - Suspend-To-RAM or equivalent (if supported) 2547 See Documentation/admin-guide/pm/sleep-states.rst. 2548 --- 42 unchanged lines hidden (view full) --- 2591 aggregation of existing arch-specific options. 2592 2593 off 2594 Disable all optional CPU mitigations. This 2595 improves system performance, but it may also 2596 expose users to several CPU vulnerabilities. 2597 Equivalent to: nopti [X86,PPC] 2598 kpti=0 [ARM64] |
| 2607 nospectre_v1 [X86,PPC] | 2599 nospectre_v1 [PPC] |
| 2608 nobp=0 [S390] 2609 nospectre_v2 [X86,PPC,S390,ARM64] 2610 spectre_v2_user=off [X86] 2611 spec_store_bypass_disable=off [X86,PPC] 2612 ssbd=force-off [ARM64] 2613 l1tf=off [X86] 2614 mds=off [X86] 2615 --- 232 unchanged lines hidden (view full) --- 2848 Format: [state][,regs][,debounce][,die] 2849 2850 nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels 2851 Format: [panic,][nopanic,][num] 2852 Valid num: 0 or 1 2853 0 - turn hardlockup detector in nmi_watchdog off 2854 1 - turn hardlockup detector in nmi_watchdog on 2855 When panic is specified, panic when an NMI watchdog | 2600 nobp=0 [S390] 2601 nospectre_v2 [X86,PPC,S390,ARM64] 2602 spectre_v2_user=off [X86] 2603 spec_store_bypass_disable=off [X86,PPC] 2604 ssbd=force-off [ARM64] 2605 l1tf=off [X86] 2606 mds=off [X86] 2607 --- 232 unchanged lines hidden (view full) --- 2840 Format: [state][,regs][,debounce][,die] 2841 2842 nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels 2843 Format: [panic,][nopanic,][num] 2844 Valid num: 0 or 1 2845 0 - turn hardlockup detector in nmi_watchdog off 2846 1 - turn hardlockup detector in nmi_watchdog on 2847 When panic is specified, panic when an NMI watchdog |
| 2856 timeout occurs (or 'nopanic' to not panic on an NMI 2857 watchdog, if CONFIG_BOOTPARAM_HARDLOCKUP_PANIC is set) 2858 To disable both hard and soft lockup detectors, | 2848 timeout occurs (or 'nopanic' to override the opposite 2849 default). To disable both hard and soft lockup detectors, |
| 2859 please see 'nowatchdog'. 2860 This is useful when you use a panic=... timeout and 2861 need the box quickly up again. 2862 2863 These settings can be accessed at runtime via 2864 the nmi_watchdog and hardlockup_panic sysctls. 2865 2866 netpoll.carrier_timeout= --- 18 unchanged lines hidden (view full) --- 2885 not work reliably with all consoles, but is known 2886 to work with serial and VGA consoles. 2887 To facilitate more flexible debugging, we also add 2888 console_suspend, a printk module parameter to control 2889 it. Users could use console_suspend (usually 2890 /sys/module/printk/parameters/console_suspend) to 2891 turn on/off it dynamically. 2892 | 2850 please see 'nowatchdog'. 2851 This is useful when you use a panic=... timeout and 2852 need the box quickly up again. 2853 2854 These settings can be accessed at runtime via 2855 the nmi_watchdog and hardlockup_panic sysctls. 2856 2857 netpoll.carrier_timeout= --- 18 unchanged lines hidden (view full) --- 2876 not work reliably with all consoles, but is known 2877 to work with serial and VGA consoles. 2878 To facilitate more flexible debugging, we also add 2879 console_suspend, a printk module parameter to control 2880 it. Users could use console_suspend (usually 2881 /sys/module/printk/parameters/console_suspend) to 2882 turn on/off it dynamically. 2883 |
| 2893 novmcoredd [KNL,KDUMP] 2894 Disable device dump. Device dump allows drivers to 2895 append dump data to vmcore so you can collect driver 2896 specified debug info. Drivers can append the data 2897 without any limit and this data is stored in memory, 2898 so this may cause significant memory stress. Disabling 2899 device dump can help save memory but the driver debug 2900 data will be no longer available. This parameter 2901 is only available when CONFIG_PROC_VMCORE_DEVICE_DUMP 2902 is set. 2903 | |
| 2904 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien 2905 caches in the slab allocator. Saves per-node memory, 2906 but will impact performance. 2907 2908 noalign [KNL,ARM] 2909 2910 noaltinstr [S390] Disables alternative instructions patching 2911 (CPU alternatives feature). --- 39 unchanged lines hidden (view full) --- 2951 read implies executable mappings 2952 2953 nofpu [MIPS,SH] Disable hardware FPU at boot time. 2954 2955 nofxsr [BUGS=X86-32] Disables x86 floating point extended 2956 register save and restore. The kernel will only save 2957 legacy floating-point registers on task switch. 2958 | 2884 noaliencache [MM, NUMA, SLAB] Disables the allocation of alien 2885 caches in the slab allocator. Saves per-node memory, 2886 but will impact performance. 2887 2888 noalign [KNL,ARM] 2889 2890 noaltinstr [S390] Disables alternative instructions patching 2891 (CPU alternatives feature). --- 39 unchanged lines hidden (view full) --- 2931 read implies executable mappings 2932 2933 nofpu [MIPS,SH] Disable hardware FPU at boot time. 2934 2935 nofxsr [BUGS=X86-32] Disables x86 floating point extended 2936 register save and restore. The kernel will only save 2937 legacy floating-point registers on task switch. 2938 |
| 2959 nohugeiomap [KNL,x86,PPC] Disable kernel huge I/O mappings. | 2939 nohugeiomap [KNL,x86] Disable kernel huge I/O mappings. |
| 2960 2961 nosmt [KNL,S390] Disable symmetric multithreading (SMT). 2962 Equivalent to smt=1. 2963 2964 [KNL,x86] Disable symmetric multithreading (SMT). 2965 nosmt=force: Force disable SMT, cannot be undone 2966 via the sysfs control file. 2967 | 2940 2941 nosmt [KNL,S390] Disable symmetric multithreading (SMT). 2942 Equivalent to smt=1. 2943 2944 [KNL,x86] Disable symmetric multithreading (SMT). 2945 nosmt=force: Force disable SMT, cannot be undone 2946 via the sysfs control file. 2947 |
| 2968 nospectre_v1 [X86,PPC] Disable mitigations for Spectre Variant 1 2969 (bounds check bypass). With this option data leaks are 2970 possible in the system. | 2948 nospectre_v1 [PPC] Disable mitigations for Spectre Variant 1 (bounds 2949 check bypass). With this option data leaks are possible 2950 in the system. |
| 2971 2972 nospectre_v2 [X86,PPC_FSL_BOOK3E,ARM64] Disable all mitigations for 2973 the Spectre variant 2 (indirect branch prediction) 2974 vulnerability. System may allow data leaks with this 2975 option. 2976 2977 nospec_store_bypass_disable 2978 [HW] Disable all mitigations for the Speculative Store Bypass vulnerability --- 184 unchanged lines hidden (view full) --- 3163 nr_uarts= [SERIAL] maximum number of UARTs to be registered. 3164 3165 numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing. 3166 Allowed values are enable and disable 3167 3168 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. 3169 'node', 'default' can be specified 3170 This can be set from sysctl after boot. | 2951 2952 nospectre_v2 [X86,PPC_FSL_BOOK3E,ARM64] Disable all mitigations for 2953 the Spectre variant 2 (indirect branch prediction) 2954 vulnerability. System may allow data leaks with this 2955 option. 2956 2957 nospec_store_bypass_disable 2958 [HW] Disable all mitigations for the Speculative Store Bypass vulnerability --- 184 unchanged lines hidden (view full) --- 3143 nr_uarts= [SERIAL] maximum number of UARTs to be registered. 3144 3145 numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing. 3146 Allowed values are enable and disable 3147 3148 numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. 3149 'node', 'default' can be specified 3150 This can be set from sysctl after boot. |
| 3171 See Documentation/admin-guide/sysctl/vm.rst for details. | 3151 See Documentation/sysctl/vm.txt for details. |
| 3172 3173 ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. 3174 See Documentation/debugging-via-ohci1394.txt for more 3175 info. 3176 3177 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands 3178 Rather than timing out after 20 ms if an EC 3179 command is not properly ACKed, override the length --- 107 unchanged lines hidden (view full) --- 3287 Halt all CPUs after the first oops has been printed for 3288 the specified number of seconds. This is to be used if 3289 your oopses keep scrolling off the screen. 3290 3291 pcbit= [HW,ISDN] 3292 3293 pcd. [PARIDE] 3294 See header of drivers/block/paride/pcd.c. | 3152 3153 ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. 3154 See Documentation/debugging-via-ohci1394.txt for more 3155 info. 3156 3157 olpc_ec_timeout= [OLPC] ms delay when issuing EC commands 3158 Rather than timing out after 20 ms if an EC 3159 command is not properly ACKed, override the length --- 107 unchanged lines hidden (view full) --- 3267 Halt all CPUs after the first oops has been printed for 3268 the specified number of seconds. This is to be used if 3269 your oopses keep scrolling off the screen. 3270 3271 pcbit= [HW,ISDN] 3272 3273 pcd. [PARIDE] 3274 See header of drivers/block/paride/pcd.c. |
| 3295 See also Documentation/admin-guide/blockdev/paride.rst. | 3275 See also Documentation/blockdev/paride.txt. |
| 3296 3297 pci=option[,option...] [PCI] various PCI subsystem options. 3298 3299 Some options herein operate on a specific device 3300 or a set of devices (<pci_dev>). These are 3301 specified in one of the following formats: 3302 3303 [<domain>:]<bus>:<dev>.<func>[/<dev>.<func>]* --- 227 unchanged lines hidden (view full) --- 3531 pd_ignore_unused 3532 [PM] 3533 Keep all power-domains already enabled by bootloader on, 3534 even if no driver has claimed them. This is useful 3535 for debug and development, but should not be 3536 needed on a platform with proper driver support. 3537 3538 pd. [PARIDE] | 3276 3277 pci=option[,option...] [PCI] various PCI subsystem options. 3278 3279 Some options herein operate on a specific device 3280 or a set of devices (<pci_dev>). These are 3281 specified in one of the following formats: 3282 3283 [<domain>:]<bus>:<dev>.<func>[/<dev>.<func>]* --- 227 unchanged lines hidden (view full) --- 3511 pd_ignore_unused 3512 [PM] 3513 Keep all power-domains already enabled by bootloader on, 3514 even if no driver has claimed them. This is useful 3515 for debug and development, but should not be 3516 needed on a platform with proper driver support. 3517 3518 pd. [PARIDE] |
| 3539 See Documentation/admin-guide/blockdev/paride.rst. | 3519 See Documentation/blockdev/paride.txt. |
| 3540 3541 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at 3542 boot time. 3543 Format: { 0 | 1 } 3544 See arch/parisc/kernel/pdc_chassis.c 3545 3546 percpu_alloc= Select which percpu first chunk allocator to use. 3547 Currently supported values are "embed" and "page". 3548 Archs may support subset or none of the selections. 3549 See comments in mm/percpu.c for details on each 3550 allocator. This parameter is primarily for debugging 3551 and performance comparison. 3552 3553 pf. [PARIDE] | 3520 3521 pdcchassis= [PARISC,HW] Disable/Enable PDC Chassis Status codes at 3522 boot time. 3523 Format: { 0 | 1 } 3524 See arch/parisc/kernel/pdc_chassis.c 3525 3526 percpu_alloc= Select which percpu first chunk allocator to use. 3527 Currently supported values are "embed" and "page". 3528 Archs may support subset or none of the selections. 3529 See comments in mm/percpu.c for details on each 3530 allocator. This parameter is primarily for debugging 3531 and performance comparison. 3532 3533 pf. [PARIDE] |
| 3554 See Documentation/admin-guide/blockdev/paride.rst. | 3534 See Documentation/blockdev/paride.txt. |
| 3555 3556 pg. [PARIDE] | 3535 3536 pg. [PARIDE] |
| 3557 See Documentation/admin-guide/blockdev/paride.rst. | 3537 See Documentation/blockdev/paride.txt. |
| 3558 3559 pirq= [SMP,APIC] Manual mp-table setup | 3538 3539 pirq= [SMP,APIC] Manual mp-table setup |
| 3560 See Documentation/x86/i386/IO-APIC.rst. | 3540 See Documentation/x86/i386/IO-APIC.txt. |
| 3561 3562 plip= [PPT,NET] Parallel port network link 3563 Format: { parport<nr> | timid | 0 } 3564 See also Documentation/admin-guide/parport.rst. 3565 3566 pmtmr= [X86] Manual setup of pmtmr I/O Port. 3567 Override pmtimer IOPort with a hex value. 3568 e.g. pmtmr=0x508 --- 92 unchanged lines hidden (view full) --- 3661 Param: "sleep" - profile D-state sleeping (millisecs). 3662 Requires CONFIG_SCHEDSTATS 3663 Param: "kvm" - profile VM exits. 3664 Param: <number> - step/bucket size as a power of 2 for 3665 statistical time based profiling. 3666 3667 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk 3668 before loading. | 3541 3542 plip= [PPT,NET] Parallel port network link 3543 Format: { parport<nr> | timid | 0 } 3544 See also Documentation/admin-guide/parport.rst. 3545 3546 pmtmr= [X86] Manual setup of pmtmr I/O Port. 3547 Override pmtimer IOPort with a hex value. 3548 e.g. pmtmr=0x508 --- 92 unchanged lines hidden (view full) --- 3641 Param: "sleep" - profile D-state sleeping (millisecs). 3642 Requires CONFIG_SCHEDSTATS 3643 Param: "kvm" - profile VM exits. 3644 Param: <number> - step/bucket size as a power of 2 for 3645 statistical time based profiling. 3646 3647 prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk 3648 before loading. |
| 3669 See Documentation/admin-guide/blockdev/ramdisk.rst. | 3649 See Documentation/blockdev/ramdisk.txt. |
| 3670 3671 psi= [KNL] Enable or disable pressure stall information 3672 tracking. 3673 Format: <bool> 3674 3675 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to 3676 probe for; one of (bare|imps|exps|lifebook|any). 3677 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports --- 5 unchanged lines hidden (view full) --- 3683 [HW,MOUSE] Set desired mouse resolution, in dpi. 3684 psmouse.smartscroll= 3685 [HW,MOUSE] Controls Logitech smartscroll autorepeat. 3686 0 = disabled, 1 = enabled (default). 3687 3688 pstore.backend= Specify the name of the pstore backend to use 3689 3690 pt. [PARIDE] | 3650 3651 psi= [KNL] Enable or disable pressure stall information 3652 tracking. 3653 Format: <bool> 3654 3655 psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to 3656 probe for; one of (bare|imps|exps|lifebook|any). 3657 psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports --- 5 unchanged lines hidden (view full) --- 3663 [HW,MOUSE] Set desired mouse resolution, in dpi. 3664 psmouse.smartscroll= 3665 [HW,MOUSE] Controls Logitech smartscroll autorepeat. 3666 0 = disabled, 1 = enabled (default). 3667 3668 pstore.backend= Specify the name of the pstore backend to use 3669 3670 pt. [PARIDE] |
| 3691 See Documentation/admin-guide/blockdev/paride.rst. | 3671 See Documentation/blockdev/paride.txt. |
| 3692 3693 pti= [X86_64] Control Page Table Isolation of user and 3694 kernel address spaces. Disabling this feature 3695 removes hardening, but improves performance of 3696 system calls and interrupts. 3697 3698 on - unconditionally enable 3699 off - unconditionally disable --- 12 unchanged lines hidden (view full) --- 3712 quiet [KNL] Disable most log messages 3713 3714 r128= [HW,DRM] 3715 3716 raid= [HW,RAID] 3717 See Documentation/admin-guide/md.rst. 3718 3719 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes | 3672 3673 pti= [X86_64] Control Page Table Isolation of user and 3674 kernel address spaces. Disabling this feature 3675 removes hardening, but improves performance of 3676 system calls and interrupts. 3677 3678 on - unconditionally enable 3679 off - unconditionally disable --- 12 unchanged lines hidden (view full) --- 3692 quiet [KNL] Disable most log messages 3693 3694 r128= [HW,DRM] 3695 3696 raid= [HW,RAID] 3697 See Documentation/admin-guide/md.rst. 3698 3699 ramdisk_size= [RAM] Sizes of RAM disks in kilobytes |
| 3720 See Documentation/admin-guide/blockdev/ramdisk.rst. | 3700 See Documentation/blockdev/ramdisk.txt. |
| 3721 3722 random.trust_cpu={on,off} 3723 [KNL] Enable or disable trusting the use of the 3724 CPU's random number generator (if available) to 3725 fully seed the kernel's CRNG. Default is controlled 3726 by CONFIG_RANDOM_TRUST_CPU. 3727 3728 ras=option[,option,...] [KNL] RAS-specific options --- 47 unchanged lines hidden (view full) --- 3776 RCU grace-period initialization. 3777 3778 rcutree.gp_preinit_delay= [KNL] 3779 Set the number of jiffies to delay each step of 3780 RCU grace-period pre-initialization, that is, 3781 the propagation of recent CPU-hotplug changes up 3782 the rcu_node combining tree. 3783 | 3701 3702 random.trust_cpu={on,off} 3703 [KNL] Enable or disable trusting the use of the 3704 CPU's random number generator (if available) to 3705 fully seed the kernel's CRNG. Default is controlled 3706 by CONFIG_RANDOM_TRUST_CPU. 3707 3708 ras=option[,option,...] [KNL] RAS-specific options --- 47 unchanged lines hidden (view full) --- 3756 RCU grace-period initialization. 3757 3758 rcutree.gp_preinit_delay= [KNL] 3759 Set the number of jiffies to delay each step of 3760 RCU grace-period pre-initialization, that is, 3761 the propagation of recent CPU-hotplug changes up 3762 the rcu_node combining tree. 3763 |
| 3784 rcutree.use_softirq= [KNL] 3785 If set to zero, move all RCU_SOFTIRQ processing to 3786 per-CPU rcuc kthreads. Defaults to a non-zero 3787 value, meaning that RCU_SOFTIRQ is used by default. 3788 Specify rcutree.use_softirq=0 to use rcuc kthreads. 3789 | |
| 3790 rcutree.rcu_fanout_exact= [KNL] 3791 Disable autobalancing of the rcu_node combining 3792 tree. This is used by rcutorture, and might 3793 possibly be useful for architectures having high 3794 cache-to-cache transfer latencies. 3795 3796 rcutree.rcu_fanout_leaf= [KNL] 3797 Change the number of CPUs assigned to each --- 287 unchanged lines hidden (view full) --- 4085 rcupdate.rcu_self_test= [KNL] 4086 Run the RCU early boot self tests 4087 4088 rdinit= [KNL] 4089 Format: <full_path> 4090 Run specified binary instead of /init from the ramdisk, 4091 used for early userspace startup. See initrd. 4092 | 3764 rcutree.rcu_fanout_exact= [KNL] 3765 Disable autobalancing of the rcu_node combining 3766 tree. This is used by rcutorture, and might 3767 possibly be useful for architectures having high 3768 cache-to-cache transfer latencies. 3769 3770 rcutree.rcu_fanout_leaf= [KNL] 3771 Change the number of CPUs assigned to each --- 287 unchanged lines hidden (view full) --- 4059 rcupdate.rcu_self_test= [KNL] 4060 Run the RCU early boot self tests 4061 4062 rdinit= [KNL] 4063 Format: <full_path> 4064 Run specified binary instead of /init from the ramdisk, 4065 used for early userspace startup. See initrd. 4066 |
| 4093 rdrand= [X86] 4094 force - Override the decision by the kernel to hide the 4095 advertisement of RDRAND support (this affects 4096 certain AMD processors because of buggy BIOS 4097 support, specifically around the suspend/resume 4098 path). 4099 | |
| 4100 rdt= [HW,X86,RDT] 4101 Turn on/off individual RDT features. List is: 4102 cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp, 4103 mba. 4104 E.g. to turn on cmt and turn off mba use: 4105 rdt=cmt,!mba 4106 4107 reboot= [KNL] --- 7 unchanged lines hidden (view full) --- 4115 reboot only), 4116 reboot_type is one of bios, acpi, kbd, triple, efi, or pci, 4117 reboot_force is either force or not specified, 4118 reboot_cpu is s[mp]#### with #### being the processor 4119 to be used for rebooting. 4120 4121 relax_domain_level= 4122 [KNL, SMP] Set scheduler's default relax_domain_level. | 4067 rdt= [HW,X86,RDT] 4068 Turn on/off individual RDT features. List is: 4069 cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, l2cdp, 4070 mba. 4071 E.g. to turn on cmt and turn off mba use: 4072 rdt=cmt,!mba 4073 4074 reboot= [KNL] --- 7 unchanged lines hidden (view full) --- 4082 reboot only), 4083 reboot_type is one of bios, acpi, kbd, triple, efi, or pci, 4084 reboot_force is either force or not specified, 4085 reboot_cpu is s[mp]#### with #### being the processor 4086 to be used for rebooting. 4087 4088 relax_domain_level= 4089 [KNL, SMP] Set scheduler's default relax_domain_level. |
| 4123 See Documentation/admin-guide/cgroup-v1/cpusets.rst. | 4090 See Documentation/cgroup-v1/cpusets.txt. |
| 4124 4125 reserve= [KNL,BUGS] Force kernel to ignore I/O ports or memory 4126 Format: <base1>,<size1>[,<base2>,<size2>,...] 4127 Reserve I/O ports or memory so the kernel won't use 4128 them. If <base> is less than 0x10000, the region 4129 is assumed to be I/O ports; otherwise it is memory. 4130 4131 reservetop= [X86-32] --- 13 unchanged lines hidden (view full) --- 4145 Specify the partition device for software suspend 4146 Format: 4147 {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>} 4148 4149 resume_offset= [SWSUSP] 4150 Specify the offset from the beginning of the partition 4151 given by "resume=" at which the swap header is located, 4152 in <PAGE_SIZE> units (needed only for swap files). | 4091 4092 reserve= [KNL,BUGS] Force kernel to ignore I/O ports or memory 4093 Format: <base1>,<size1>[,<base2>,<size2>,...] 4094 Reserve I/O ports or memory so the kernel won't use 4095 them. If <base> is less than 0x10000, the region 4096 is assumed to be I/O ports; otherwise it is memory. 4097 4098 reservetop= [X86-32] --- 13 unchanged lines hidden (view full) --- 4112 Specify the partition device for software suspend 4113 Format: 4114 {/dev/<dev> | PARTUUID=<uuid> | <int>:<int> | <hex>} 4115 4116 resume_offset= [SWSUSP] 4117 Specify the offset from the beginning of the partition 4118 given by "resume=" at which the swap header is located, 4119 in <PAGE_SIZE> units (needed only for swap files). |
| 4153 See Documentation/power/swsusp-and-swap-files.rst | 4120 See Documentation/power/swsusp-and-swap-files.txt |
| 4154 4155 resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to 4156 read the resume files 4157 4158 resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. 4159 Useful for devices that are detected asynchronously 4160 (e.g. USB and MMC devices). 4161 --- 211 unchanged lines hidden (view full) --- 4373 functionality. 4374 4375 softlockup_all_cpu_backtrace= 4376 [KNL] Should the soft-lockup detector generate 4377 backtraces on all cpus. 4378 Format: <integer> 4379 4380 sonypi.*= [HW] Sony Programmable I/O Control Device driver | 4121 4122 resumedelay= [HIBERNATION] Delay (in seconds) to pause before attempting to 4123 read the resume files 4124 4125 resumewait [HIBERNATION] Wait (indefinitely) for resume device to show up. 4126 Useful for devices that are detected asynchronously 4127 (e.g. USB and MMC devices). 4128 --- 211 unchanged lines hidden (view full) --- 4340 functionality. 4341 4342 softlockup_all_cpu_backtrace= 4343 [KNL] Should the soft-lockup detector generate 4344 backtraces on all cpus. 4345 Format: <integer> 4346 4347 sonypi.*= [HW] Sony Programmable I/O Control Device driver |
| 4381 See Documentation/admin-guide/laptops/sonypi.rst | 4348 See Documentation/laptops/sonypi.txt |
| 4382 4383 spectre_v2= [X86] Control mitigation of Spectre variant 2 4384 (indirect branch speculation) vulnerability. 4385 The default operation protects the kernel from 4386 user space attacks. 4387 4388 on - unconditionally enable, implies 4389 spectre_v2_user=on --- 235 unchanged lines hidden (view full) --- 4625 Sets the number of seconds to remain in a suspend test 4626 mode before resuming the system (see 4627 /sys/power/pm_test). Only available when CONFIG_PM_DEBUG 4628 is set. Default value is 5. 4629 4630 swapaccount=[0|1] 4631 [KNL] Enable accounting of swap in memory resource 4632 controller if no parameter or 1 is given or disable | 4349 4350 spectre_v2= [X86] Control mitigation of Spectre variant 2 4351 (indirect branch speculation) vulnerability. 4352 The default operation protects the kernel from 4353 user space attacks. 4354 4355 on - unconditionally enable, implies 4356 spectre_v2_user=on --- 235 unchanged lines hidden (view full) --- 4592 Sets the number of seconds to remain in a suspend test 4593 mode before resuming the system (see 4594 /sys/power/pm_test). Only available when CONFIG_PM_DEBUG 4595 is set. Default value is 5. 4596 4597 swapaccount=[0|1] 4598 [KNL] Enable accounting of swap in memory resource 4599 controller if no parameter or 1 is given or disable |
| 4633 it if 0 is given (See Documentation/admin-guide/cgroup-v1/memory.rst) | 4600 it if 0 is given (See Documentation/cgroup-v1/memory.txt) |
| 4634 4635 swiotlb= [ARM,IA-64,PPC,MIPS,X86] 4636 Format: { <int> | force | noforce } 4637 <int> -- Number of I/O TLB slabs 4638 force -- force using of bounce buffers even if they 4639 wouldn't be automatically used by the kernel 4640 noforce -- Never use bounce buffers (for debugging) 4641 --- 58 unchanged lines hidden (view full) --- 4700 Specify global default ACPI thermal zone polling rate 4701 <deci-seconds>: poll all this frequency 4702 0: no polling (default) 4703 4704 threadirqs [KNL] 4705 Force threading of all interrupt handlers except those 4706 marked explicitly IRQF_NO_THREAD. 4707 | 4601 4602 swiotlb= [ARM,IA-64,PPC,MIPS,X86] 4603 Format: { <int> | force | noforce } 4604 <int> -- Number of I/O TLB slabs 4605 force -- force using of bounce buffers even if they 4606 wouldn't be automatically used by the kernel 4607 noforce -- Never use bounce buffers (for debugging) 4608 --- 58 unchanged lines hidden (view full) --- 4667 Specify global default ACPI thermal zone polling rate 4668 <deci-seconds>: poll all this frequency 4669 0: no polling (default) 4670 4671 threadirqs [KNL] 4672 Force threading of all interrupt handlers except those 4673 marked explicitly IRQF_NO_THREAD. 4674 |
| 4675 tmem [KNL,XEN] 4676 Enable the Transcendent memory driver if built-in. 4677 4678 tmem.cleancache=0|1 [KNL, XEN] 4679 Default is on (1). Disable the usage of the cleancache 4680 API to send anonymous pages to the hypervisor. 4681 4682 tmem.frontswap=0|1 [KNL, XEN] 4683 Default is on (1). Disable the usage of the frontswap 4684 API to send swap pages to the hypervisor. If disabled 4685 the selfballooning and selfshrinking are force disabled. 4686 4687 tmem.selfballooning=0|1 [KNL, XEN] 4688 Default is on (1). Disable the driving of swap pages 4689 to the hypervisor. 4690 4691 tmem.selfshrinking=0|1 [KNL, XEN] 4692 Default is on (1). Partial swapoff that immediately 4693 transfers pages from Xen hypervisor back to the 4694 kernel based on different criteria. 4695 |
|
| 4708 topology= [S390] 4709 Format: {off | on} 4710 Specify if the kernel should make use of the cpu 4711 topology information if the hardware supports this. 4712 The scheduler will make use of this information and 4713 e.g. base its process migration decisions on it. 4714 Default is on. 4715 --- 326 unchanged lines hidden (view full) --- 5042 5043 Try vdso32=0 if you encounter an error that says: 5044 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 5045 5046 vector= [IA-64,SMP] 5047 vector=percpu: enable percpu vector domain 5048 5049 video= [FB] Frame buffer configuration | 4696 topology= [S390] 4697 Format: {off | on} 4698 Specify if the kernel should make use of the cpu 4699 topology information if the hardware supports this. 4700 The scheduler will make use of this information and 4701 e.g. base its process migration decisions on it. 4702 Default is on. 4703 --- 326 unchanged lines hidden (view full) --- 5030 5031 Try vdso32=0 if you encounter an error that says: 5032 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! 5033 5034 vector= [IA-64,SMP] 5035 vector=percpu: enable percpu vector domain 5036 5037 video= [FB] Frame buffer configuration |
| 5050 See Documentation/fb/modedb.rst. | 5038 See Documentation/fb/modedb.txt. |
| 5051 5052 video.brightness_switch_enabled= [0,1] 5053 If set to 1, on receiving an ACPI notify event 5054 generated by hotkey, video driver will adjust brightness 5055 level and then send out the event to user space through 5056 the allocated input device; If set to 0, video driver 5057 will only send out the event without touching backlight 5058 brightness level. --- 11 unchanged lines hidden (view full) --- 5070 request_irq()) 5071 <id> := (optional) platform device id 5072 example: 5073 virtio_mmio.device=1K@0x100b0000:48:7 5074 5075 Can be used multiple times for multiple devices. 5076 5077 vga= [BOOT,X86-32] Select a particular video mode | 5039 5040 video.brightness_switch_enabled= [0,1] 5041 If set to 1, on receiving an ACPI notify event 5042 generated by hotkey, video driver will adjust brightness 5043 level and then send out the event to user space through 5044 the allocated input device; If set to 0, video driver 5045 will only send out the event without touching backlight 5046 brightness level. --- 11 unchanged lines hidden (view full) --- 5058 request_irq()) 5059 <id> := (optional) platform device id 5060 example: 5061 virtio_mmio.device=1K@0x100b0000:48:7 5062 5063 Can be used multiple times for multiple devices. 5064 5065 vga= [BOOT,X86-32] Select a particular video mode |
| 5078 See Documentation/x86/boot.rst and 5079 Documentation/admin-guide/svga.rst. | 5066 See Documentation/x86/boot.txt and 5067 Documentation/svga.txt. |
| 5080 Use vga=ask for menu. 5081 This is actually a boot loader parameter; the value is 5082 passed to the kernel using a special protocol. 5083 5084 vm_debug[=options] [KNL] Available with CONFIG_DEBUG_VM=y. 5085 May slow down system boot speed, especially when 5086 enabled on systems with a large amount of memory. 5087 All options are enabled by default, and this --- 28 unchanged lines hidden (view full) --- 5116 Controls the behavior of vsyscalls (i.e. calls to 5117 fixed addresses of 0xffffffffff600x00 from legacy 5118 code). Most statically-linked binaries and older 5119 versions of glibc use these calls. Because these 5120 functions are at fixed addresses, they make nice 5121 targets for exploits that can control RIP. 5122 5123 emulate [default] Vsyscalls turn into traps and are | 5068 Use vga=ask for menu. 5069 This is actually a boot loader parameter; the value is 5070 passed to the kernel using a special protocol. 5071 5072 vm_debug[=options] [KNL] Available with CONFIG_DEBUG_VM=y. 5073 May slow down system boot speed, especially when 5074 enabled on systems with a large amount of memory. 5075 All options are enabled by default, and this --- 28 unchanged lines hidden (view full) --- 5104 Controls the behavior of vsyscalls (i.e. calls to 5105 fixed addresses of 0xffffffffff600x00 from legacy 5106 code). Most statically-linked binaries and older 5107 versions of glibc use these calls. Because these 5108 functions are at fixed addresses, they make nice 5109 targets for exploits that can control RIP. 5110 5111 emulate [default] Vsyscalls turn into traps and are |
| 5124 emulated reasonably safely. The vsyscall 5125 page is readable. | 5112 emulated reasonably safely. |
| 5126 | 5113 |
| 5127 xonly Vsyscalls turn into traps and are 5128 emulated reasonably safely. The vsyscall 5129 page is not readable. | 5114 native Vsyscalls are native syscall instructions. 5115 This is a little bit faster than trapping 5116 and makes a few dynamic recompilers work 5117 better than they would in emulation mode. 5118 It also makes exploits much easier to write. |
| 5130 5131 none Vsyscalls don't work at all. This makes 5132 them quite hard to use for exploits but 5133 might break your system. 5134 5135 vt.color= [VT] Default text color. 5136 Format: 0xYX, X = foreground, Y = background. 5137 Default: 0x07 = light gray on black. --- 39 unchanged lines hidden (view full) --- 5177 5178 vt.italic= [VT] Default color for italic text; 0-15. 5179 Default: 2 = green. 5180 5181 vt.underline= [VT] Default color for underlined text; 0-15. 5182 Default: 3 = cyan. 5183 5184 watchdog timers [HW,WDT] For information on watchdog timers, | 5119 5120 none Vsyscalls don't work at all. This makes 5121 them quite hard to use for exploits but 5122 might break your system. 5123 5124 vt.color= [VT] Default text color. 5125 Format: 0xYX, X = foreground, Y = background. 5126 Default: 0x07 = light gray on black. --- 39 unchanged lines hidden (view full) --- 5166 5167 vt.italic= [VT] Default color for italic text; 0-15. 5168 Default: 2 = green. 5169 5170 vt.underline= [VT] Default color for underlined text; 0-15. 5171 Default: 3 = cyan. 5172 5173 watchdog timers [HW,WDT] For information on watchdog timers, |
| 5185 see Documentation/watchdog/watchdog-parameters.rst | 5174 see Documentation/watchdog/watchdog-parameters.txt |
| 5186 or other driver-specific files in the 5187 Documentation/watchdog/ directory. 5188 5189 watchdog_thresh= 5190 [KNL] 5191 Set the hard lockup detector stall duration 5192 threshold in seconds. The soft lockup detector 5193 threshold is set to twice the value. A value of 0 --- 75 unchanged lines hidden (view full) --- 5269 5270 xen_nopvspin [X86,XEN] 5271 Disables the ticketlock slowpath using Xen PV 5272 optimizations. 5273 5274 xen_nopv [X86] 5275 Disables the PV optimizations forcing the HVM guest to 5276 run as generic HVM guest with no PV drivers. | 5175 or other driver-specific files in the 5176 Documentation/watchdog/ directory. 5177 5178 watchdog_thresh= 5179 [KNL] 5180 Set the hard lockup detector stall duration 5181 threshold in seconds. The soft lockup detector 5182 threshold is set to twice the value. A value of 0 --- 75 unchanged lines hidden (view full) --- 5258 5259 xen_nopvspin [X86,XEN] 5260 Disables the ticketlock slowpath using Xen PV 5261 optimizations. 5262 5263 xen_nopv [X86] 5264 Disables the PV optimizations forcing the HVM guest to 5265 run as generic HVM guest with no PV drivers. |
| 5277 This option is obsoleted by the "nopv" option, which 5278 has equivalent effect for XEN platform. | |
| 5279 5280 xen_scrub_pages= [XEN] 5281 Boolean option to control scrubbing pages before giving them back 5282 to Xen, for use by other domains. Can be also changed at runtime 5283 with /sys/devices/system/xen_memory/xen_memory0/scrub_pages. 5284 Default value controlled with CONFIG_XEN_SCRUB_PAGES_DEFAULT. 5285 5286 xen_timer_slop= [X86-64,XEN] 5287 Set the timer slop (in nanoseconds) for the virtual Xen 5288 timers (default is 100000). This adjusts the minimum 5289 delta of virtualized Xen timers, where lower values 5290 improve timer resolution at the expense of processing 5291 more timer interrupts. 5292 | 5266 5267 xen_scrub_pages= [XEN] 5268 Boolean option to control scrubbing pages before giving them back 5269 to Xen, for use by other domains. Can be also changed at runtime 5270 with /sys/devices/system/xen_memory/xen_memory0/scrub_pages. 5271 Default value controlled with CONFIG_XEN_SCRUB_PAGES_DEFAULT. 5272 5273 xen_timer_slop= [X86-64,XEN] 5274 Set the timer slop (in nanoseconds) for the virtual Xen 5275 timers (default is 100000). This adjusts the minimum 5276 delta of virtualized Xen timers, where lower values 5277 improve timer resolution at the expense of processing 5278 more timer interrupts. 5279 |
| 5293 nopv= [X86,XEN,KVM,HYPER_V,VMWARE] 5294 Disables the PV optimizations forcing the guest to run 5295 as generic guest with no PV drivers. Currently support 5296 XEN HVM, KVM, HYPER_V and VMWARE guest. 5297 | |
| 5298 xirc2ps_cs= [NET,PCMCIA] 5299 Format: 5300 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] 5301 | 5280 xirc2ps_cs= [NET,PCMCIA] 5281 Format: 5282 <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] 5283 |
| 5302 xive= [PPC] 5303 By default on POWER9 and above, the kernel will 5304 natively use the XIVE interrupt controller. This option 5305 allows the fallback firmware mode to be used: 5306 5307 off Fallback to firmware control of XIVE interrupt 5308 controller on both pseries and powernv 5309 platforms. Only useful on POWER9 and above. 5310 | |
| 5311 xhci-hcd.quirks [USB,KNL] 5312 A hex value specifying bitmask with supplemental xhci 5313 host controller quirks. Meaning of each bit can be 5314 consulted in header drivers/usb/host/xhci.h. | 5284 xhci-hcd.quirks [USB,KNL] 5285 A hex value specifying bitmask with supplemental xhci 5286 host controller quirks. Meaning of each bit can be 5287 consulted in header drivers/usb/host/xhci.h. |