callers. These ioctls attempted to enable and disable the ACPI
interpreter at runtime. In practice, it is not possible to boot with
ACPI and then disable it on many systems and trying to do so can cause
crashes, interrupt storms, etc. Binary compatibility with userland is
retained.
MFC after: 2 days
infrastructure. It's not perfect, but it's a lot better than what
we've been using so far. The following rules apply to this:
o BSD component names should be capitalised
o Layer names should be taken from the non-CA set for now. We
may elect to add some new BSD-specific layers later.
- Make it possible to turn off selective debugging flags or layers
by listing them in debug.acpi.layer or debug.acpi.level prefixed
with !.
- Fully implement support for avoiding nodes in the ACPI namespace.
Nodes may be listed in the debug.acpi.avoid environment variable;
these nodes and all their children will be ignored (although still
scanned over) by ACPI functions which scan the namespace. Multiple
nodes can be specified, separated by whitespace.
- Implement support for selectively disabling ACPI subsystem components
via the debug.acpi.disable environment variable. The following
components can be disabled:
o bus creation/scanning of the ACPI 'bus'
o children attachment of children to the ACPI 'bus'
o button the acpi_button control-method button driver
o ec the acpi_ec embedded-controller driver
o isa acpi replacement of PnP BIOS for ISA device discovery
o lid the control-method lid switch driver
o pci pci root-bus discovery
o processor CPU power/speed management
o thermal system temperature detection and control
o timer ACPI timecounter
Multiple components may be disabled by specifying their name(s)
separated by whitespace.
- Add support for ioctl registration. ACPI subsystem components may
register ioctl handlers with the /dev/acpi generic ioctl handler,
allowing us to avoid the need for a multitude of /dev/acpi* control
devices, etc.
ACPICA. Most of these are still works in progress. Support exists for:
- Fixed feature and control method power, lid and sleep buttons.
- Detection of ISA PnP devices using ACPI namespace.
- Detection of PCI root busses using ACPI namespace.
- CPU throttling and sleep states (incomplete)
- Thermal monitoring and cooling control (incomplete)
- Interface to platform embedded controllers (mostly complete)
- ACPI timer (incomplete)
- Simple userland control of sleep states.
- Shutdown and poweroff.
