DUe to https://github.com/rust-lang/rust/issues/114447 direct access to
static mut variables causes a warning which will be turned into an
error in the 2024 edition.
The workaround is to use `addr_of!()` and `addr_of_mut!()` macros and
then dereference that.
Signed-off-by: Sean Cross <sean@xobs.io>
With Rust 1.76.0, we no longer support building with `#![no_std]` or
`panic = "abort"`, both of which are required within the kernel. As a
workaround, go back to building the kernel under
`riscv32imac-unknown-none-elf`.
Signed-off-by: Sean Cross <sean@xobs.io>
Support passing process arguments in register 2 as part of arguments to
a process.
This requires updating the `InitialProcess` struct that is received from
the loader, and so requires modeifications to be made in tandem.
Signed-off-by: Sean Cross <sean@xobs.io>
a lot of re-import warnings have cropped up. While I appreciate
their studiousness on this, the problem is that removing some
of these exports in the API crate could mean that future users
who want access to some API features that aren't used in this
configuration are now unaccessible.
I think it's not a huge problem at the moment, just spam-cleaning
the warnings because there are too many to deal with carefully
at the moment.
When enumerating processes, the `find_process()` process didn't consult
whether a process was actually free. This resulted in a crash,
particularly when attaching a debugger to a crashed process.
Signed-off-by: Sean Cross <sean@xobs.io>
Mark `MemoryRange::as_slice()` and `MemoryRange::as_slice_mut()` as
unsafe.
This is due to the fact that not all representable types can be cast to
an arbitrary value. For example, if Process A sends random values to
Process B, then Process B casts the memory to a slice of `bool`, then
any values that are not 0 or 1 are undefined.
Because these functions can leak UB into the program, they are marked as
unsafe.
This patch adds `unsafe {}` blocks to all instances where this function
is called. Additionally, all instances have been checked to verify that
they do not cast to any invalid types -- most use `u8` or `u32`.
Additionally, the long-deprecated `MemoryRange::from_parts()` call was
removed, since that causes UB without being marked as unsafe.
Signed-off-by: Sean Cross <sean@xobs.io>
With Rust 1.71.0, mut detection has changed slightly, and it is more
aggressive about warning when things do not need to be mutable.
Remove these from the `services` file.
Signed-off-by: Sean Cross <sean@xobs.io>
When debugging an invalid process (e.g. not yet run, terminated, etc.)
return an error rather than silently continuing.
Signed-off-by: Sean Cross <sean@xobs.io>
This adds a basic gdb server. Currently, it is possible to list
processes and inspect memory and threads. It is not yet possible to
actually interact with code (e.g. no breakpoints and no single
stepping).
Signed-off-by: Sean Cross <sean@xobs.io>
Add an initial reimplementation of the gdb-stub using the gdbstub
backing crate.
This supports process enumeration and basic thread investigation.
Processes will pause when the debugger is inspecting them. Memory and
registers can be investigated. Threads can be listed and selected.
It does not yet support breakpoints.
Signed-off-by: Sean Cross <sean@xobs.io>
Even when the print-debug feature isn't turned on, println! macro is still able to output some critical non-debug info to the console such as panics, process crashes and violations, etc. Debugging messages are printed with klog! macro that's disabled when debug-print feature is not set.
this commit adds the facilities to extract eh_frame[_header]
sections and pass it to each process.
A bump is required to `std` to extract the passed parameters.
it works with e.g. shellchat, but not vault.
still scratching my head on what's gone wrong -- it's
crashing in the pre-boot, which means something is not
mapped right for some case that wasn't caught in the
earlier testing.
Note the current thread in the original process when its quantum
expires. This will allow us to clean up after ourselves when a context
switch occurs, and will help to prevent thread starvation.
Signed-off-by: Sean Cross <sean@xobs.io>
For some reason, the current thread becomes 0 during suspend or resume.
This causes an error during boot.
Patch this up while we figure out what's causing it.
Signed-off-by: Sean Cross <sean@xobs.io>
There were a few corner cases when it came to thread selection. Namely,
the same thread had a higher chance of repeatedly being executed.
Clean up these corner cases, and as a result get libstd tests to pass.
Signed-off-by: Sean Cross <sean@xobs.io>
Use a multiply-based algorithm to count the number of leading zeroes.
This results in a function that's just 20 instructions long.
Signed-off-by: Sean Cross <sean@xobs.io>
THe act of finding a runnable thread is so common, yet the kernel
contains three ways of doing this.
Use a unified function to select the next available thread.
Signed-off-by: Sean Cross <sean@xobs.io>
Previously the `current_thread` was set to 0, which is invalid. Set the
`current_thread` so that it defaults to the initial thread ID.
Signed-off-by: Sean Cross <sean@xobs.io>
@xobs found a scheduler bug that would trigger a runnable process
search every time a scalar message returned. This fixes the problem,
causing the quantum to go back to the caller as intended.
Improves performance on the syscall by about 40%.
- strip out gdb-stub. Per xobs, the feature never worked, and it
depends upon a branch of a git repo which is not allowed by crates.io
Since the feature hasn't been developed, and crates.io will not
allow even an optional feature that points to a git repo, the feature
was stripped out.
- rename "kernel" to "xous-kernel", so that we can live in a crates.io
package namespace that is specific to Xous.
still have to figure out the riscv package issue.
Hosted mode spawns processes very differently, and this difference was
not reflected after changes were made to native mode.
Signed-off-by: Sean Cross <sean@xobs.io>
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>
We now us `ProcessStartup` as the return type. This builds in tset
mode, hosted mode, and RISC-V mode.
Process Startup is still not implemented for RISC-V mode.
Signed-off-by: Sean Cross <sean@xobs.io>
