Due to several errors, multi-page lending did not work properly.
To begin with, if a page was not allocated then it would not be able to
be sent. That is, if you allocated 8192 bytes but only ever accessed the
first 4096 bytes, then an error would be encountered when lending the
unaccessed upper page.
Furthermore, due to a striding error in accessing pointers, half-pages
were treated as full pages.
Signed-off-by: Sean Cross <sean@xobs.io>
This implements a syscall to shut down a server. Servers may not be shut
down if they have outstanding messages that they have seen but not
responded to.
Signed-off-by: Sean Cross <sean@xobs.io>
This reworks the server queue to add a "generation counter". This
counter ensures messages are removed from the queue in the order they
were added, even if they are jumbled up within the queue itself.
Signed-off-by: Sean Cross <sean@xobs.io>
Previously, we would only look at the top item on the server queue. If
it was not a known message, we would return an error.
This patch changes this behavior to look through the entire queue for
something we can take, and then clean it up as we go along.
This allow for having outstanding requests in the queue an forms the
backbone of the sleep server.
Signed-off-by: Sean Cross <sean@xobs.io>
This tracks a variable that has been renamed, and was preventing the
kernel from compiling when debug printing is enabled.
This fixes#19.
Signed-off-by: Sean Cross <sean@xobs.io>
Servers will, by default, get randomly-assigned SIDs. Certain servers
will want to have well-known SIDs, such as the log server or the
nameserver. These will use a separate call in order to perform this
priveledged operation.
A subsequent patch will add `CreateServer`.
Signed-off-by: Sean Cross <sean@xobs.io>
This fixes issues regarding passing memory between processes.
We now properly catch `ReturnMemory` and give the memory back.
Signed-off-by: Sean Cross <sean@xobs.io>
The `sender` was, previously, somewhat mislabeled. It was a combination
of PID and TID, except when it wasn't.
Instead, make this value a combination of ConnectionID and queue index.
This makes it easier to reason about which connection we're responding
to.
Additionally, don't expose teh global Server Index Table to userspace
programs.
Signed-off-by: Sean Cross <sean@xobs.io>
Server IDs were being improperly indexed, resulting in a
probably-invalid server index being returned.
Adjust these so that correct server indices are returned.
Signed-off-by: Sean Cross <sean@xobs.io>
Cargo appears to cache packages in the workspace when multiple packages
use the same crate. Unfortunately, Xous uses different features
depending on whether it's running in the kernel or in userspace.
Pull the kernel version of "xous" in under a different namespace in
order to force it to use a different build.
Signed-off-by: Sean Cross <sean@xobs.io>
The kernel should run in a `no_std` environment, which means it must
currently run without `alloc`. We have our own allocation methods when
running on baremetal hardware.
Begin the work to break out the allocation method so that it will work
on both desktop and baremetal environments.
Signed-off-by: Sean Cross <sean@xobs.io>
Connections weren't getting multiplexed correctly. As a result, they
would respond with the wrong message to a given thread.
Signed-off-by: Sean Cross <sean@xobs.io>
We now have two tests. These tests may be run either in parallel or in series.
If they are run in parallel, then they will each have their own thread
local storage, and each will initialize things from scratch.
If they are run in series, then the thread local storage will be reused
between the two processes.
Signed-off-by: Sean Cross <sean@xobs.io>
This gets basic scalar message passing working again. With this, the
following operations may be performed:
* Starting a server
* Connecting to a server
* Sending a scalar message
Care must be taken to not overflow a server's queue, particularly if
writers are faster than readers.
Signed-off-by: Sean Cross <sean@xobs.io>
The goal is to get a basic message passing engine working that will also
function as a device that works on real hardware.
This is still reworking it to function correctly on a desktop system.
Once that is working, it will be reworked to function once again on
hardware.
Signed-off-by: Sean Cross <sean@xobs.io>
This prepares for new calls to init SystemServices and the MemoryManager
so that they can be initialized with something other than a
KernelArguments struct.
Signed-off-by: Sean Cross <sean@xobs.io>
This refactors the kernel so that it *can* run on baremetal, but it can
also run as part of a full system.
This will aid in developing, and ensure that a minimum amount of unsafe
code is present within the kernel.
Signed-off-by: Sean Cross <sean@xobs.io>
This improves page sharing. Permissions are retained during sharing,
and we should now be able to share multiple pages. Additionally, this
lays the groundwork for mutable sharing.
Signed-off-by: Sean Cross <sean@xobs.io>
