Configuring Solaris ACPI at boot-time
By danasblog on Jun 14, 2005
As part of the new Solaris ACPI subsystem integrated as part of Newboot, I've added a new bit to the "acpi-user-options" boot option.
Historically, acpi-user-options=0x2 has been the only publicly documented option, and is used to disable Solaris use of ACPI for CPU enumeration and interrupt routing. Generally speaking, the pattern has historically been to set acpi-user-options=0x2 if there's any problem at all, just to see if the system works better. Changes made in Solaris 10 have made ACPI use in Solaris much more robust, so disabling use of ACPI should not be required as frequently as in previous releases.
Beginning with Newboot, integrated into Solaris source in April (2005), acpi-user-options has changed in a couple of ways:
The previous ACPI subsystem did not put the system into “ACPI” mode, but left the system in “Legacy” mode, where the system BIOS retains control of the system. The new Solaris ACPI subsystem based on ACPI CA now places the system in ACPI mode by default.
acpi-user-options=0x8 causes the new Solaris ACPI subsystem to leave the system in Legacy mode. This is the first option one should try if ACPI-related issues are suspected.
acpi-user-options=0x4 is present in Solaris 10, and causes both the previous Solaris ACPI subsystem and the new subsystem to partially disable use of ACPI – but Hyper-Threaded CPUs are still enumerated using ACPI tables. This is the second option one should use if ACPI-related issues are suspected.
acpi-user-options=0x2 is present in Solaris 10, and causes both the previous Solaris ACPI subsystem and the new subsystem to disable the use of ACPI.
Generally speaking, the new Solaris ACPI subsystem seems to do very well by default. I'll blog separately about some issues I've diagnosed that appeared to be ACPI-related but turned out to be to something else (BIOS issues, actually).