this is a fairly major re-org of where key constants go that
define platform features. things that were in xous-rs that were
platform specific (namely precursor) were moved into a boards file,
and things that are generic to the system (like PAGE_SIZE) are moved
to a public location in xous-rs::arch.
Implement a functioning CreateProcess syscall on riscv. This call
creates a server in the child process, and connects the server to the
parent. The parent can communicate with the child process using this
server.
The Server ID is passed as four `u32` values to the entrypoint function.
This can be reassembled into something that can then be passed to the
`ReceiveMessage` syscall.
Signed-off-by: Sean Cross <sean@xobs.io>
Mark the private fields in a `MemoryRange` struct as being private. This
allows us to perform operations on the memory range armed with the
knowledge that the entire range is valid and unaliased.
Signed-off-by: Sean Cross <sean@xobs.io>
This function allows for creating arbitrary memory ranges. Mark this
function as `unsafe` in order to warn users that this can be used to
create invalid memory regions.
Signed-off-by: Sean Cross <sean@xobs.io>
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>
