311 lines
12 KiB
Plaintext
311 lines
12 KiB
Plaintext
|
AMD64 specific boot options
|
||
|
|
|
||
|
|
There are many others (usually documented in driver documentation), but
|
||
|
|
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 on uncorrected errors, log corrected errors
|
||
|
|
1: panic or SIGBUS on uncorrected errors, log corrected errors
|
||
|
|
2: SIGBUS or log uncorrected errors, log corrected errors
|
||
|
|
3: never panic or SIGBUS, log all errors (for testing only)
|
||
|
|
Default is 1
|
||
|
|
Can be also set using sysfs which is preferable.
|
||
|
|
|
||
|
|
nomce (for compatibility with i386): same as mce=off
|
||
|
|
|
||
|
|
Everything else is in sysfs now.
|
||
|
|
|
||
|
|
APICs
|
||
|
|
|
||
|
|
apic Use IO-APIC. Default
|
||
|
|
|
||
|
|
noapic Don't use the IO-APIC.
|
||
|
|
|
||
|
|
disableapic Don't use the local APIC
|
||
|
|
|
||
|
|
nolapic Don't use the local APIC (alias for i386 compatibility)
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
Early Console
|
||
|
|
|
||
|
|
syntax: earlyprintk=vga
|
||
|
|
earlyprintk=serial[,ttySn[,baudrate]]
|
||
|
|
|
||
|
|
The early console is useful when the kernel crashes before the
|
||
|
|
normal console is initialized. It is not enabled by
|
||
|
|
default because it has some cosmetic problems.
|
||
|
|
Append ,keep to not disable it when the real console takes over.
|
||
|
|
Only vga or serial at a time, not both.
|
||
|
|
Currently only ttyS0 and ttyS1 are supported.
|
||
|
|
Interaction with the standard serial driver is not very good.
|
||
|
|
The VGA output is eventually overwritten by the real console.
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
report_lost_ticks
|
||
|
|
Report when timer interrupts are lost because some code turned off
|
||
|
|
interrupts for too long.
|
||
|
|
|
||
|
|
nmi_watchdog=NUMBER[,panic]
|
||
|
|
NUMBER can be:
|
||
|
|
0 don't use an NMI watchdog
|
||
|
|
1 use the IO-APIC timer for the NMI watchdog
|
||
|
|
2 use the local APIC for the NMI watchdog using a performance counter. Note
|
||
|
|
This will use one performance counter and the local APIC's performance
|
||
|
|
vector.
|
||
|
|
When panic is specified panic when an NMI watchdog timeout occurs.
|
||
|
|
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
|
||
|
|
Don't do power saving in the idle loop using HLT, but poll for rescheduling
|
||
|
|
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] | a[cpi] | e[fi] [, [w]arm | [c]old]
|
||
|
|
bios Use the CPU reboot vector for warm reset
|
||
|
|
warm Don't set the cold reboot flag
|
||
|
|
cold Set the cold reboot flag
|
||
|
|
triple Force a triple fault (init)
|
||
|
|
kbd Use the keyboard controller. cold reset (default)
|
||
|
|
acpi Use the ACPI RESET_REG in the FADT. If ACPI is not configured or the
|
||
|
|
ACPI reset does not work, the reboot path attempts the reset using
|
||
|
|
the keyboard controller.
|
||
|
|
efi Use efi reset_system runtime service. If EFI is not configured or the
|
||
|
|
EFI reset does not work, the reboot path attempts the reset using
|
||
|
|
the keyboard controller.
|
||
|
|
|
||
|
|
Using warm reset will be much faster especially on big memory
|
||
|
|
systems because the BIOS will not go through the memory check.
|
||
|
|
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(default)
|
||
|
|
off Disable
|
||
|
|
|
||
|
|
SMP
|
||
|
|
|
||
|
|
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=CMDLINE
|
||
|
|
If a number, fakes CMDLINE nodes and ignores NUMA setup of the
|
||
|
|
actual machine. Otherwise, system memory is configured
|
||
|
|
depending on the sizes and coefficients listed. For example:
|
||
|
|
numa=fake=2*512,1024,4*256,*128
|
||
|
|
gives two 512M nodes, a 1024M node, four 256M nodes, and the
|
||
|
|
rest split into 128M chunks. If the last character of CMDLINE
|
||
|
|
is a *, the remaining memory is divided up equally among its
|
||
|
|
coefficient:
|
||
|
|
numa=fake=2*512,2*
|
||
|
|
gives two 512M nodes and the rest split into two nodes.
|
||
|
|
Otherwise, the remaining system RAM is allocated to an
|
||
|
|
additional node.
|
||
|
|
|
||
|
|
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
|
||
|
|
|
||
|
|
acpi=off Don't enable ACPI
|
||
|
|
acpi=ht Use ACPI boot table parsing, but don't enable 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
|
||
|
|
pci=conf1 Use conf1 access.
|
||
|
|
pci=conf2 Use conf2 access.
|
||
|
|
pci=rom Assign ROMs.
|
||
|
|
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 (input/output memory management unit)
|
||
|
|
|
||
|
|
Currently four x86-64 PCI-DMA mapping implementations exist:
|
||
|
|
|
||
|
|
1. <arch/x86_64/kernel/pci-nommu.c>: use no hardware/software IOMMU at all
|
||
|
|
(e.g. because you have < 3 GB memory).
|
||
|
|
Kernel boot message: "PCI-DMA: Disabling IOMMU"
|
||
|
|
|
||
|
|
2. <arch/x86_64/kernel/pci-gart.c>: AMD GART based hardware IOMMU.
|
||
|
|
Kernel boot message: "PCI-DMA: using GART IOMMU"
|
||
|
|
|
||
|
|
3. <arch/x86_64/kernel/pci-swiotlb.c> : Software IOMMU implementation. Used
|
||
|
|
e.g. if there is no hardware IOMMU in the system and it is need because
|
||
|
|
you have >3GB memory or told the kernel to us it (iommu=soft))
|
||
|
|
Kernel boot message: "PCI-DMA: Using software bounce buffering
|
||
|
|
for IO (SWIOTLB)"
|
||
|
|
|
||
|
|
4. <arch/x86_64/pci-calgary.c> : IBM Calgary hardware IOMMU. Used in IBM
|
||
|
|
pSeries and xSeries servers. This hardware IOMMU supports DMA address
|
||
|
|
mapping with memory protection, etc.
|
||
|
|
Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
|
||
|
|
|
||
|
|
iommu=[<size>][,noagp][,off][,force][,noforce][,leak[=<nr_of_leak_pages>]
|
||
|
|
[,memaper[=<order>]][,merge][,forcesac][,fullflush][,nomerge]
|
||
|
|
[,noaperture][,calgary]
|
||
|
|
|
||
|
|
General iommu options:
|
||
|
|
off Don't initialize and use any kind of IOMMU.
|
||
|
|
noforce Don't force hardware IOMMU usage when it is not needed.
|
||
|
|
(default).
|
||
|
|
force Force the use of the hardware IOMMU even when it is
|
||
|
|
not actually needed (e.g. because < 3 GB memory).
|
||
|
|
soft Use software bounce buffering (SWIOTLB) (default for
|
||
|
|
Intel machines). This can be used to prevent the usage
|
||
|
|
of an available hardware IOMMU.
|
||
|
|
|
||
|
|
iommu options only relevant to the AMD GART hardware IOMMU:
|
||
|
|
<size> Set the size of the remapping area in bytes.
|
||
|
|
allowed Overwrite iommu off workarounds for specific chipsets.
|
||
|
|
fullflush Flush IOMMU on each allocation (default).
|
||
|
|
nofullflush Don't use IOMMU fullflush.
|
||
|
|
leak Turn on simple iommu leak tracing (only when
|
||
|
|
CONFIG_IOMMU_LEAK is on). Default number of leak pages
|
||
|
|
is 20.
|
||
|
|
memaper[=<order>] Allocate an own aperture over RAM with size 32MB<<order.
|
||
|
|
(default: order=1, i.e. 64MB)
|
||
|
|
merge Do scatter-gather (SG) merging. Implies "force"
|
||
|
|
(experimental).
|
||
|
|
nomerge Don't do scatter-gather (SG) merging.
|
||
|
|
noaperture Ask the IOMMU not to touch the aperture for AGP.
|
||
|
|
forcesac Force single-address cycle (SAC) mode for masks <40bits
|
||
|
|
(experimental).
|
||
|
|
noagp Don't initialize the AGP driver and use full aperture.
|
||
|
|
allowdac Allow double-address cycle (DAC) mode, i.e. DMA >4GB.
|
||
|
|
DAC is used with 32-bit PCI to push a 64-bit address in
|
||
|
|
two cycles. When off all DMA over >4GB is forced through
|
||
|
|
an IOMMU or software bounce buffering.
|
||
|
|
nodac Forbid DAC mode, i.e. DMA >4GB.
|
||
|
|
panic Always panic when IOMMU overflows.
|
||
|
|
calgary Use the Calgary IOMMU if it is available
|
||
|
|
|
||
|
|
iommu options only relevant to the software bounce buffering (SWIOTLB) IOMMU
|
||
|
|
implementation:
|
||
|
|
swiotlb=<pages>[,force]
|
||
|
|
<pages> Prereserve that many 128K pages for the software IO
|
||
|
|
bounce buffering.
|
||
|
|
force Force all IO through the software TLB.
|
||
|
|
|
||
|
|
Settings for the IBM Calgary hardware IOMMU currently found in IBM
|
||
|
|
pSeries and xSeries machines:
|
||
|
|
|
||
|
|
calgary=[64k,128k,256k,512k,1M,2M,4M,8M]
|
||
|
|
calgary=[translate_empty_slots]
|
||
|
|
calgary=[disable=<PCI bus number>]
|
||
|
|
panic Always panic when IOMMU overflows
|
||
|
|
|
||
|
|
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=<PCI bus number> - 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 N 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)
|
||
|
|
|
||
|
|
Miscellaneous
|
||
|
|
|
||
|
|
nogbpages
|
||
|
|
Do not use GB pages for kernel direct mappings.
|
||
|
|
gbpages
|
||
|
|
Use GB pages for kernel direct mappings.
|