x86/x86_64/boot-options.rst

1 .. SPDX-License-Identifier: GPL-2.0
30 		Disable features for corrected errors, e.g. polling timer
39 		Do not opt-in to Local MCE delivery. Use legacy method
62 		Don't overwrite the bios-set CMCI threshold. This boot option
69 		Force-enable recoverable machine check code paths
80 	Use IO-APIC. Default
83 	Don't use the IO-APIC.
86 	Don't use the local APIC
89      Don't use the local APIC (alias for i386 compatibility)
92 	See Documentation/x86/i386/IO-APIC.rst
95 	Don't set up the APIC timer
98 	Don't check the IO-APIC timer. This can work around
99 	problems with incorrect timer initialization on some boards.
102 	Do APIC timer calibration using the pmtimer. Implies
103 	apicmaintimer. Useful when your PIT timer is totally broken.
112     Don't use the HPET timer.
155      Don't stop other CPUs on reboot. This can make reboot more reliable
177     Don't parse the HMAT table for NUMA setup, or soft-reserved memory
224   pci=assign-busses
235 Multiple x86-64 PCI-DMA mapping implementations exist, for example:
239       Kernel boot message: "PCI-DMA: Disabling IOMMU"
242       Kernel boot message: "PCI-DMA: using GART IOMMU"
244    3. <arch/x86_64/kernel/pci-swiotlb.c> : Software IOMMU implementation. Used
247       Kernel boot message: "PCI-DMA: Using software bounce buffering
250    4. <arch/x86_64/pci-calgary.c> : IBM Calgary hardware IOMMU. Used in IBM
253       Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
289       Do scatter-gather (SG) merging. Implies "force" (experimental).
291       Don't do scatter-gather (SG) merging.
324       example, the built-in graphics adapter resides on the first bridge
327       space might stop working. Use this option if you have devices that