Important points:
----------------
1. Works fine for pb926 + qemu.
2. Scan code logic for kryboard is not complete.
We just have generic keys and shift working.
3. Mouse scancodes are collected but not decoded.
4. Right now we are doing enable_irq(), just before we go for waiting
again for new irqs. This is not correct but we had latency issues.
This needs to be fixed immediately.
5. Also it seems like the notify_clot count should be an atomic
variable. Needs to be discussed.
- Userspace irq handling for timer.
- If no runnable task is left. scheduler busy loops in user context
of last runnable task until a new task becomes runnable.
Irqs can now touch runqueues and do async wakeups. This necessitated
that we implement all wake up wait and runqueue locking work with irqs.
All this, assumes that in an SMP setup we may have cross-cpu wake ups,
runqueue manipulation. If we later decide that we only wake up threads
in the current container, (and lock containers to cpus) we won't really
need spinlocks, or irq disabling anymore. The current set up might be
trivially less responsive, but is more flexible.
A 16-bit device number or id further distinguishes a device on the
system in addition to the device type. This is meant to be used for
the very first identification of the device for further probing. Any
further info is available by userspace mapping and probing.
Followed the kernel physical memory reservation convention
with devices. Devices that are possessable by userspace
are created as boot-time capabilities and placed under the kernel
resources devmem_free capability list. Any userspace container
that is defined with the possession of the device would delete the
device capability making it unavailable to further requests.
cinfo array is now freed along with other init memory.
bootmem allocator memory is reduced to be completely used up.
free boot memory now prints the used free memory as well.
In the former case, when a child was exiting there was a risk of being preempted while it
was also taken away from the runqueue. In this situatuion, it may not have had
the chance of waking up the parent in case if it waits for the child to exit.
This was also true for suspend & resume so they were patched also.
It is not very straightforward to reach a capabilities list. We
now use a single function to find out a capability by its id and
its list, since the two are used frequently together (i.e. cap
removal and destruction)
Implemented a protocol between a client and its pager to
request and get a capability to ipc to another client of the pager.
Pager first ensures the request is valid from its client.
It then tries to use a greater capability that it possesses, to
produce a new capability that the client requested. Once the kernel
validates the correct one and replicates/reduces it to client's
need, it grants it to the client.
Thread ids now contain their container ids in the top 2 nibbles.
Threads on other containers can be addressed by changing those
two nibbles. The addressing of inter-container threads are
subject to capabilities.
VIRTMEM and PHYSMEM are theoretically separate resources to be
protected than a MAP resource, which is meant to protect the syscall
privileges.
In practice MAP is always used together with a VIRTMEM and a PHYSMEM
resource, therefore reach VIRTMEM/PHYSMEM resource is now merged with
the MAP capability, combining the micro-permission bits.
We still have to have the pager structs because they possess intermediate
data during boot up such as for transferring of capability lists to
boot stack one-by-one, and then to newly generated ktcbs.
