- every pci device which implements _PRT acpi method is considered to
be a pci-to-pci bridge
- acpi driver constructs a hierarchy of pci-to-pci bridges
- when pci driver identifies a pci-to-pci bridge it tells acpi driver
what is the primary and the secondary bus for this device
- when pci requests IRQ routing information from acpi, it passes the
bus number too to be able to identify the device accurately
- kernel turns on IO APICs if no_apic is _not_ set or is equal 0
- pci driver must use the acpi driver to setup IRQ routing otherwise
the system cannot work correctly except systems like KVM that use
only legacy (E)ISA IRQs 0-15
- 99% of the code is Intel's ACPICA. The license is compliant with BSD
and GNU and virtually all systems that use ACPI use this code, For
instance it is part of the Linux kernel.
- The only minix specific files are
acpi.c
osminixxf.c
platform/acminix.h
and
include/minix/acpi.h
- At the moment the driver does not register interrupt hooks which I
believe is mainly for handling PnP, events like "battery level is
low" and power management. Should not be difficult to add it if need
be.
- The interface to the outside world is virtually non-existent except
a trivial message based service for PCI driver to query which device
is connected to what IRQ line. This will evolve as more components
start using this driver. VM, Scheduler and IOMMU are the possible
users right now.
- because of dependency on a native 64bit (long long, part of c99) it
is compiled only with a gnu-like compilers which in case of Minix
includes gcc llvm-gcc and clang
