- most global variables carry information which is specific to the
local CPU and each CPU must have its own copy
- cpu local variable must be declared in cpulocal.h between
DECLARE_CPULOCAL_START and DECLARE_CPULOCAL_END markers using
DECLARE_CPULOCAL macro
- to access the cpu local data the provided macros must be used
get_cpu_var(cpu, name)
get_cpu_var_ptr(cpu, name)
get_cpulocal_var(name)
get_cpulocal_var_ptr(name)
- using this macros makes future changes in the implementation
possible
- switching to ELF will make the declaration of cpu local data much
simpler, e.g.
CPULOCAL int blah;
anywhere in the kernel source code
- 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
- kernel exports DSDP (the root pointer where ACPI parsing starts) and
apic_enabled in the machine structure.
- ACPI driver uses DSDP to locate ACPI in memory. acpi_enabled tell
PCI driver to query ACPI for IRQ routing information.
This makes it easier to
- have non-base system drivers (get clobbered by global system.conf)
- have drivers as packages (can't touch global system.conf)
- make configs part of the drivers/servers instead of in global file
(makes system parts more self-contained)
