X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fx86_64%2Fboot-options.txt;h=5c86ed6f0448a8e2378a4ba62d6cedecf236215c;hb=refs%2Fheads%2Fvserver;hp=7f8570a7bdbabc11813a0947fa4db24587aaf0f3;hpb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;p=linux-2.6.git diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 7f8570a7b..5c86ed6f0 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -6,6 +6,18 @@ only the AMD64 specific ones are listed here. Machine check mce=off disable machine check + mce=bootlog Enable logging of machine checks left over from booting. + Disabled by default on AMD because some BIOS leave bogus ones. + If your BIOS doesn't do that it's a good idea to enable though + to make sure you log even machine check events that result + in a reboot. On Intel systems it is enabled by default. + mce=nobootlog + Disable boot machine check logging. + mce=tolerancelevel (number) + 0: always panic, 1: panic if deadlock possible, + 2: try to avoid panic, 3: never panic or exit (for testing) + default is 1 + Can be also set using sysfs which is preferable. nomce (for compatibility with i386): same as mce=off @@ -14,8 +26,6 @@ Machine check APICs apic Use IO-APIC. Default - Unless you have an NVidia or VIA/Uniprocessor board. - Then it defaults to off. noapic Don't use the IO-APIC. @@ -25,6 +35,27 @@ APICs pirq=... See Documentation/i386/IO-APIC.txt + noapictimer Don't set up the APIC timer + + no_timer_check Don't check the IO-APIC timer. This can work around + problems with incorrect timer initialization on some boards. + + apicmaintimer Run time keeping from the local APIC timer instead + of using the PIT/HPET interrupt for this. This is useful + when the PIT/HPET interrupts are unreliable. + + noapicmaintimer Don't do time keeping using the APIC timer. + Useful when this option was auto selected, but doesn't work. + + apicpmtimer + Do APIC timer calibration using the pmtimer. Implies + apicmaintimer. Useful when your PIT timer is totally + broken. + + disable_8254_timer / enable_8254_timer + Enable interrupt 0 timer routing over the 8254 in addition to over + the IO-APIC. The kernel tries to set a sensible default. + Early Console syntax: earlyprintk=vga @@ -44,7 +75,7 @@ Timing notsc Don't use the CPU time stamp counter to read the wall time. This can be used to work around timing problems on multiprocessor systems - with not properly synchronized CPUs. Only useful with a SMP kernel + with not properly synchronized CPUs. report_lost_ticks Report when timer interrupts are lost because some code turned off @@ -61,6 +92,9 @@ Timing This is useful when you use a panic=... timeout and need the box quickly up again. + nohpet + Don't use the HPET timer. + Idle loop idle=poll @@ -68,13 +102,16 @@ Idle loop event. This will make the CPUs eat a lot more power, but may be useful to get slightly better performance in multiprocessor benchmarks. It also makes some profiling using performance counters more accurate. + Please note that on systems with MONITOR/MWAIT support (like Intel EM64T + CPUs) this option has no performance advantage over the normal idle loop. + It may also interact badly with hyperthreading. Rebooting reboot=b[ios] | t[riple] | k[bd] [, [w]arm | [c]old] - bios Use the CPU reboto vector for warm reset + bios Use the CPU reboot vector for warm reset warm Don't set the cold reboot flag - cold Set the cold reboto flag + cold Set the cold reboot flag triple Force a triple fault (init) kbd Use the keyboard controller. cold reset (default) @@ -83,26 +120,17 @@ Rebooting Disadvantage is that not all hardware will be completely reinitialized on reboot so there may be boot problems on some systems. + reboot=force + + Don't stop other CPUs on reboot. This can make reboot more reliable + in some cases. + Non Executable Mappings noexec=on|off - on Enable + on Enable(default) off Disable - noforce (default) Don't enable by default for heap/stack/data, - but allow PROT_EXEC to be effective - - noexec32=opt{,opt} - - Control the no exec default for 32bit processes. - Requires noexec=on or noexec=noforce to be effective. - - Valid options: - all,on Heap,stack,data is non executable. - off (default) Heap,stack,data is executable - stack Stack is non executable, heap/data is. - force Don't imply PROT_EXEC for PROT_READ - compat (default) Imply PROT_EXEC for PROT_READ SMP @@ -112,10 +140,21 @@ SMP cpumask=MASK only use cpus with bits set in mask + additional_cpus=NUM Allow NUM more CPUs for hotplug + (defaults are specified by the BIOS, see Documentation/x86_64/cpu-hotplug-spec) + NUMA numa=off Only set up a single NUMA node spanning all memory. + numa=noacpi Don't parse the SRAT table for NUMA setup + + numa=fake=X Fake X nodes and ignore NUMA setup of the actual machine. + + numa=hotadd=percent + Only allow hotadd memory to preallocate page structures upto + percent of already available memory. + numa=hotadd=0 will disable hotadd memory. ACPI @@ -124,6 +163,12 @@ ACPI interpreter acpi=force Force ACPI on (currently not needed) + acpi=strict Disable out of spec ACPI workarounds. + + acpi_sci={edge,level,high,low} Set up ACPI SCI interrupt. + + acpi=noirq Don't route interrupts + PCI pci=off Don't use PCI @@ -133,11 +178,12 @@ PCI pci=assign-busses Assign busses pci=irqmask=MASK Set PCI interrupt mask to MASK pci=lastbus=NUMBER Scan upto NUMBER busses, no matter what the mptable says. + pci=noacpi Don't use ACPI to set up PCI interrupt routing. IOMMU iommu=[size][,noagp][,off][,force][,noforce][,leak][,memaper[=order]][,merge] - [,forcesac][,fullflush][,nomerge][,noaperture] + [,forcesac][,fullflush][,nomerge][,noaperture][,calgary] size set size of iommu (in bytes) noagp don't initialize the AGP driver and use full aperture. off don't use the IOMMU @@ -153,8 +199,67 @@ IOMMU allowed overwrite iommu off workarounds for specific chipsets. soft Use software bounce buffering (default for Intel machines) noaperture Don't touch the aperture for AGP. + allowdac Allow DMA >4GB + When off all DMA over >4GB is forced through an IOMMU or bounce + buffering. + nodac Forbid DMA >4GB + panic Always panic when IOMMU overflows + calgary Use the Calgary IOMMU if it is available swiotlb=pages[,force] pages Prereserve that many 128K pages for the software IO bounce buffering. force Force all IO through the software TLB. + + calgary=[64k,128k,256k,512k,1M,2M,4M,8M] + calgary=[translate_empty_slots] + calgary=[disable=] + + 64k,...,8M - Set the size of each PCI slot's translation table + when using the Calgary IOMMU. This is the size of the translation + table itself in main memory. The smallest table, 64k, covers an IO + space of 32MB; the largest, 8MB table, can cover an IO space of + 4GB. Normally the kernel will make the right choice by itself. + + translate_empty_slots - Enable translation even on slots that have + no devices attached to them, in case a device will be hotplugged + in the future. + + disable= - Disable translation on a given PHB. For + example, the built-in graphics adapter resides on the first bridge + (PCI bus number 0); if translation (isolation) is enabled on this + bridge, X servers that access the hardware directly from user + space might stop working. Use this option if you have devices that + are accessed from userspace directly on some PCI host bridge. + +Debugging + + oops=panic Always panic on oopses. Default is to just kill the process, + but there is a small probability of deadlocking the machine. + This will also cause panics on machine check exceptions. + Useful together with panic=30 to trigger a reboot. + + kstack=N Print that many words from the kernel stack in oops dumps. + + pagefaulttrace Dump all page faults. Only useful for extreme debugging + and will create a lot of output. + + call_trace=[old|both|newfallback|new] + old: use old inexact backtracer + new: use new exact dwarf2 unwinder + both: print entries from both + newfallback: use new unwinder but fall back to old if it gets + stuck (default) + + call_trace=[old|both|newfallback|new] + old: use old inexact backtracer + new: use new exact dwarf2 unwinder + both: print entries from both + newfallback: use new unwinder but fall back to old if it gets + stuck (default) + +Misc + + noreplacement Don't replace instructions with more appropriate ones + for the CPU. This may be useful on asymmetric MP systems + where some CPU have less capabilities than the others.