"acpi=off" vs. "noacpi"

[Ross Minkov]

Hello,

Does anyone know if there is any difference between "acpi=off" and "noacpi"?

I normaly put this in the kickstart file, i.e.:

bootloader --location=mbr --append="noapic noacpi"

Some context:
RHEL4 / 2.6.9-55.ELsmp on hp BL465c

Thanks,
Ross

[TY 007]

Hello Ross,

"acpi=off" should be sufficient.

Sample usage of "noacpi": "pci=noacpi"

Thanks

[Ross Minkov]

Thanks TY 007 for taking the time to respond to my question, but you didn't really answer it.

Is there or isn't there a difference between the 2?

Thanks,
Ross

[Ivan Ferreira · Accepted solution]

The function is the same, but you can specify more options with acpi= other than enable/disable:

force -- enable ACPI if default was off
off -- disable ACPI if default was on (same as noacpi)
noirq -- do not use ACPI for IRQ routing
ht -- run only enough ACPI to enable Hyper Threading
strict -- Be less tolerant of platforms that are not strictly ACPI specification compliant.

[Ross Minkov]

Ivan,

This was exactly what I was looking for. Could you tell me what was your source of information, please?

Thanks,
Ross

[Ivan Ferreira]

The Linux Kernel documentation, normally installed in /usr/share/doc with the kernel-docs package or included in the kernel source. The file is kernel-parameters.txt, online versions everywhere with simple googling:

http://fxr.watson.org/fxr/source/Documentation/kernel-parameters.txt?v=linux-2.4.22