Commit bbea90bb authored by Changbin Du's avatar Changbin Du Committed by Jonathan Corbet

Documentation: x86: convert x86_64/boot-options.txt to reST

This converts the plain text documentation to reStructuredText format and
add it to Sphinx TOC tree. No essential content change.
Signed-off-by: default avatarChangbin Du <changbin.du@gmail.com>
Reviewed-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 8fffdc93
......@@ -27,3 +27,4 @@ x86-specific Documentation
resctrl_ui
usb-legacy-support
i386/index
x86_64/index
AMD64 specific boot options
.. SPDX-License-Identifier: GPL-2.0
===========================
AMD64 Specific Boot Options
===========================
There are many others (usually documented in driver documentation), but
only the AMD64 specific ones are listed here.
Machine check
Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables.
=============
Please see Documentation/x86/x86_64/machinecheck for sysfs runtime tunables.
mce=off
Disable machine check
......@@ -64,64 +68,83 @@ Machine check
mce=recovery
Force-enable recoverable machine check code paths
nomce (for compatibility with i386): same as mce=off
nomce (for compatibility with i386)
same as mce=off
Everything else is in sysfs now.
APICs
=====
apic Use IO-APIC. Default
apic
Use IO-APIC. Default
noapic Don't use the IO-APIC.
noapic
Don't use the IO-APIC.
disableapic Don't use the local APIC
disableapic
Don't use the local APIC
nolapic Don't use the local APIC (alias for i386 compatibility)
nolapic
Don't use the local APIC (alias for i386 compatibility)
pirq=... See Documentation/x86/i386/IO-APIC.txt
pirq=...
See Documentation/x86/i386/IO-APIC.txt
noapictimer Don't set up the APIC timer
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.
no_timer_check Don't check the IO-APIC timer. This can work around
problems with incorrect timer initialization on some boards.
apicpmtimer
Do APIC timer calibration using the pmtimer. Implies
apicmaintimer. Useful when your PIT timer is totally
broken.
Do APIC timer calibration using the pmtimer. Implies
apicmaintimer. Useful when your PIT timer is totally broken.
Timing
======
notsc
Deprecated, use tsc=unstable instead.
Deprecated, use tsc=unstable instead.
nohpet
Don't use the HPET timer.
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.
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.
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.
......@@ -129,67 +152,83 @@ Rebooting
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.
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
on
Enable(default)
off
Disable
NUMA
====
numa=off Only set up a single NUMA node spanning all memory.
numa=off
Only set up a single NUMA node spanning all memory.
numa=noacpi Don't parse the SRAT table for NUMA setup
numa=noacpi
Don't parse the SRAT table for NUMA setup
numa=fake=<size>[MG]
If given as a memory unit, fills all system RAM with nodes of
size interleaved over physical nodes.
If given as a memory unit, fills all system RAM with nodes of
size interleaved over physical nodes.
numa=fake=<N>
If given as an integer, fills all system RAM with N fake nodes
interleaved over physical nodes.
If given as an integer, fills all system RAM with N fake nodes
interleaved over physical nodes.
numa=fake=<N>U
If given as an integer followed by 'U', it will divide each
physical node into N emulated nodes.
If given as an integer followed by 'U', it will divide each
physical node into N emulated nodes.
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
acpi=nocmcff Disable firmware first mode for corrected errors. This
disables parsing the HEST CMC error source to check if
firmware has set the FF flag. This may result in
duplicate corrected error reports.
====
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
acpi=nocmcff
Disable firmware first mode for corrected errors. This
disables parsing the HEST CMC error source to check if
firmware has set the FF flag. This may result in
duplicate corrected error reports.
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 up to NUMBER busses, no matter what the mptable says.
pci=noacpi Don't use ACPI to set up PCI interrupt routing.
===
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 up to 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)
Multiple x86-64 PCI-DMA mapping implementations exist, for example:
===========================================
Multiple x86-64 PCI-DMA mapping implementations exist, for example:
1. <lib/dma-direct.c>: use no hardware/software IOMMU at all
(e.g. because you have < 3 GB memory).
......@@ -209,70 +248,88 @@ IOMMU (input/output memory management unit)
mapping with memory protection, etc.
Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
iommu=[<size>][,noagp][,off][,force][,noforce]
[,memaper[=<order>]][,merge][,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.
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.
noagp Don't initialize the AGP driver and use full aperture.
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:
::
iommu=[<size>][,noagp][,off][,force][,noforce]
[,memaper[=<order>]][,merge][,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.
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.
noagp
Don't initialize the AGP driver and use full aperture.
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.
<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:
Settings for the IBM Calgary hardware IOMMU currently found in IBM
pSeries and xSeries machines
calgary=[64k,128k,256k,512k,1M,2M,4M,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.
calgary=[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.
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 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.
panic
Always panic when IOMMU overflows
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.
Miscellaneous
=============
nogbpages
Do not use GB pages for kernel direct mappings.
gbpages
Use GB pages for kernel direct mappings.
nogbpages
Do not use GB pages for kernel direct mappings.
gbpages
Use GB pages for kernel direct mappings.
.. SPDX-License-Identifier: GPL-2.0
==============
x86_64 Support
==============
.. toctree::
:maxdepth: 2
boot-options
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