This is a holdover from Citra, where the 3DS has both
WaitSynchronization1 and WaitSynchronizationN. The switch only has one
form of wait synchronizing (literally WaitSynchonization). This allows
us to throw out code that doesn't apply at all to the Switch kernel.
Because of this unnecessary dichotomy within the wait synchronization
utilities, we were also neglecting to properly handle waiting on
multiple objects.
While we're at it, we can also scrub out any lingering references to
WaitSynchronization1/WaitSynchronizationN in comments, and change them
to WaitSynchronization (or remove them if the mention no longer
applies).
The actual behavior of this function is slightly more complex than what
we're currently doing within the supervisor call. To avoid dumping most
of this behavior in the supervisor call itself, we can migrate this to
another function.
This member variable is entirely unused. It was only set but never
actually utilized. Given that, we can remove it to get rid of noise in
the thread interface.
Essentially performs the inverse of svcMapProcessCodeMemory. This unmaps
the aliasing region first, then restores the general traits of the
aliased memory.
What this entails, is:
- Restoring Read/Write permissions to the VMA.
- Restoring its memory state to reflect it as a general heap memory region.
- Clearing the memory attributes on the region.
This gives us significantly more control over where in the
initialization process we start execution of the main process.
Previously we were running the main process before the CPU or GPU
threads were initialized (not good). This amends execution to start
after all of our threads are properly set up.
Initially required due to the split codepath with how the initial main
process instance was initialized. We used to initialize the process
like:
Init() {
main_process = Process::Create(...);
kernel.MakeCurrentProcess(main_process.get());
}
Load() {
const auto load_result = loader.Load(*kernel.GetCurrentProcess());
if (load_result != Loader::ResultStatus::Success) {
// Handle error here.
}
...
}
which presented a problem.
Setting a created process as the main process would set the page table
for that process as the main page table. This is fine... until we get to
the part that the page table can have its size changed in the Load()
function via NPDM metadata, which can dictate either a 32-bit, 36-bit,
or 39-bit usable address space.
Now that we have full control over the process' creation in load, we can
simply set the initial process as the main process after all the loading
is done, reflecting the potential page table changes without any
special-casing behavior.
We can also remove the cache flushing within LoadModule(), as execution
wouldn't have even begun yet during all usages of this function, now
that we have the initialization order cleaned up.
Now that we have dependencies on the initialization order, we can move
the creation of the main process to a more sensible area: where we
actually load in the executable data.
This allows localizing the creation and loading of the process in one
location, making the initialization of the process much nicer to trace.
Like with CPU emulation, we generally don't want to fire off the threads
immediately after the relevant classes are initialized, we want to do
this after all necessary data is done loading first.
This splits the thread creation into its own interface member function
to allow controlling when these threads in particular get created.
Our initialization process is a little wonky than one would expect when
it comes to code flow. We initialize the CPU last, as opposed to
hardware, where the CPU obviously needs to be first, otherwise nothing
else would work, and we have code that adds checks to get around this.
For example, in the page table setting code, we check to see if the
system is turned on before we even notify the CPU instances of a page
table switch. This results in dead code (at the moment), because the
only time a page table switch will occur is when the system is *not*
running, preventing the emulated CPU instances from being notified of a
page table switch in a convenient manner (technically the code path
could be taken, but we don't emulate the process creation svc handlers
yet).
This moves the threads creation into its own member function of the core
manager and restores a little order (and predictability) to our
initialization process.
Previously, in the multi-threaded cases, we'd kick off several threads
before even the main kernel process was created and ready to execute (gross!).
Now the initialization process is like so:
Initialization:
1. Timers
2. CPU
3. Kernel
4. Filesystem stuff (kind of gross, but can be amended trivially)
5. Applet stuff (ditto in terms of being kind of gross)
6. Main process (will be moved into the loading step in a following
change)
7. Telemetry (this should be initialized last in the future).
8. Services (4 and 5 should ideally be alongside this).
9. GDB (gross. Uses namespace scope state. Needs to be refactored into a
class or booted altogether).
10. Renderer
11. GPU (will also have its threads created in a separate step in a
following change).
Which... isn't *ideal* per-se, however getting rid of the wonky
intertwining of CPU state initialization out of this mix gets rid of
most of the footguns when it comes to our initialization process.
Some objects declare their handle type as const, while others declare it
as constexpr. This makes the const ones constexpr for consistency, and
prevent unexpected compilation errors if these happen to be attempted to be
used within a constexpr context.
These indicate options that alter how a read/write is performed.
Currently we don't need to handle these, as the only one that seems to
be used is for writes, but all the custom options ever seem to do is
immediate flushing, which we already do by default.
We need to ensure dynarmic gets a valid pointer if the page table is
resized (the relevant pointers would be invalidated in this scenario).
In this scenario, the page table can be resized depending on what kind
of address space is specified within the NPDM metadata (if it's
present).
Adjusts the interface of the wrappers to take a system reference, which
allows accessing a system instance without using the global accessors.
This also allows getting rid of all global accessors within the
supervisor call handling code. While this does make the wrappers
themselves slightly more noisy, this will be further cleaned up in a
follow-up. This eliminates the global system accessors in the current
code while preserving the existing interface.
Keeps the return type consistent with the function name. While we're at
it, we can also reduce the amount of boilerplate involved with handling
these by using structured bindings.
BitField has been trivially copyable since
e99a148628, so we can eliminate these
TODO comments and use ReadObject() directly instead of memcpying the
data.
Rather than make a full copy of the path, we can just use a string view
and truncate the viewed portion of the string instead of creating a totally
new truncated string.
In several places, we have request parsers where there's nothing to
really parse, simply because the HLE function in question operates on
buffers. In these cases we can just remove these instances altogether.
In the other cases, we can retrieve the relevant members from the parser
and at least log them out, giving them some use.
Applies the override specifier where applicable. In the case of
destructors that are defaulted in their definition, they can
simply be removed.
This also removes the unnecessary inclusions being done in audin_u and
audrec_u, given their close proximity.
Quite a bit of these were out of sync with Switchbrew (and in some cases
entirely wrong). While we're at it, also expand the section of named
members. A segment within the control metadata is used to specify
maximum values for the user, device, and cache storage max sizes and
journal sizes.
These appear to be generally used by the am service (e.g. in
CreateCacheStorage, etc).
We need to be checking whether or not the given address is within the
kernel address space or if the given address isn't word-aligned and bail
in these scenarios instead of trashing any kernel state.
For whatever reason, shared memory was being used here instead of
transfer memory, which (quite clearly) will not work based off the name
of the function.
This corrects this wonky usage of shared memory.
Given server sessions can be given a name, we should allow retrieving
it instead of using the default implementation of GetName(), which would
just return "[UNKNOWN KERNEL OBJECT]".
The AddressArbiter type isn't actually used, given the arbiter itself
isn't a direct kernel object (or object that implements the wait object
facilities).
Given this, we can remove the enum entry entirely.
Similarly like svcGetProcessList, this retrieves the list of threads
from the current process. In the kernel itself, a process instance
maintains a list of threads, which are used within this function.
Threads are registered to a process' thread list at thread
initialization, and unregistered from the list upon thread destruction
(if said thread has a non-null owning process).
We assert on the debug event case, as we currently don't implement
kernel debug objects.
Now that ShouldWait() is a const qualified member function, this one can
be made const qualified as well, since it can handle passing a const
qualified this pointer to ShouldWait().
Previously this was performing a u64 + int sign conversion. When dealing
with addresses, we should generally be keeping the arithmetic in the
same signedness type.
This also gets rid of the static lifetime of the constant, as there's no
need to make a trivial type like this potentially live for the entire
duration of the program.
This doesn't really provide any benefit to the resource limit interface.
There's no way for callers to any of the service functions for resource
limits to provide a custom name, so all created instances of resource
limits other than the system resource limit would have a name of
"Unknown".
The system resource limit itself is already trivially identifiable from
its limit values, so there's no real need to take up space in the object to
identify one object meaningfully out of N total objects.
Since C++17, the introduction of deduction guides for locking facilities
means that we no longer need to hardcode the mutex type into the locks
themselves, making it easier to switch mutex types, should it ever be
necessary in the future.
Since C++17, we no longer need to explicitly specify the type of the
mutex within the lock_guard. The type system can now deduce these with
deduction guides.
Based off RE, most of these structure members are register values, which
makes, sense given this service is used to convey fatal errors.
One member indicates the program entry point address, one is a set of
bit flags used to determine which registers to print, and one member
indicates the architecture type.
The only member that still isn't determined is the final member within
the data structure.
The kernel makes sure that the given size to unmap is always the same
size as the entire region managed by the shared memory instance,
otherwise it returns an error code signifying an invalid size.
This is similarly done for transfer memory (which we already check for).
This was initially added to prevent problems from stubbed/not implemented NFC services, but as we never encountered such and as it's only used in a deprecated function anyway, I guess we can just remove it to prevent more clutter of the settings.
Reports the (mostly) correct size through svcGetInfo now for queries to
total used physical memory. This still doesn't correctly handle memory
allocated via svcMapPhysicalMemory, however, we don't currently handle
that case anyways.
This will make operating with the process-related SVC commands much
nicer in the future (the parameter representing the stack size in
svcStartProcess is a 64-bit value).
These functions act in tandem similar to how a lock or mutex require a
balanced lock()/unlock() sequence.
EnterFatalSection simply increments a counter for how many times it has
been called, while LeaveFatalSection ensures that a previous call to
EnterFatalSection has occured. If a previous call has occurred (the
counter is not zero), then the counter gets decremented as one would
expect. If a previous call has not occurred (the counter is zero), then
an error code is returned.
In some cases, our callbacks were using s64 as a parameter, and in other
cases, they were using an int, which is inconsistent.
To make all callbacks consistent, we can just use an s64 as the type for
late cycles, given it gets rid of the need to cast internally.
While we're at it, also resolve some signed/unsigned conversions that
were occurring related to the callback registration.
One behavior that we weren't handling properly in our heap allocation
process was the ability for the heap to be shrunk down in size if a
larger size was previously requested.
This adds the basic behavior to do so and also gets rid of HeapFree, as
it's no longer necessary now that we have allocations and deallocations
going through the same API function.
While we're at it, fully document the behavior that this function
performs.
Makes it more obvious that this function is intending to stand in for
the actual supervisor call itself, and not acting as a general heap
allocation function.
Also the following change will merge the freeing behavior of HeapFree
into this function, so leaving it as HeapAllocate would be misleading.
In cases where HeapAllocate is called with the same size of the current
heap, we can simply do nothing and return successfully.
This avoids doing work where we otherwise don't have to. This is also
what the kernel itself does in this scenario.
Another holdover from citra that can be tossed out is the notion of the
heap needing to be allocated in different addresses. On the switch, the
base address of the heap will always be managed by the memory allocator
in the kernel, so this doesn't need to be specified in the function's
interface itself.
The heap on the switch is always allocated with read/write permissions,
so we don't need to add specifying the memory permissions as part of the
heap allocation itself either.
This also corrects the error code returned from within the function.
If the size of the heap is larger than the entire heap region, then the
kernel will report an out of memory condition.
The use of a shared_ptr is an implementation detail of the VMManager
itself when mapping memory. Because of that, we shouldn't require all
users of the CodeSet to have to allocate the shared_ptr ahead of time.
It's intended that CodeSet simply pass in the required direct data, and
that the memory manager takes care of it from that point on.
This means we just do the shared pointer allocation in a single place,
when loading modules, as opposed to in each loader.
This source file was utilizing its own version of the NSO header.
Instead of keeping this around, we can have the patch manager also use
the version of the header that we have defined in loader/nso.h
The total struct itself is 0x100 (256) bytes in size, so we should be
providing that amount of data.
Without the data, this can result in omitted data from the final loaded
NSO file.
Makes it more evident that one is for actual code and one is for actual
data. Mutable and static are less than ideal terms here, because
read-only data is technically not mutable, but we were mapping it with
that label.
In 93da8e0abf, the page table construct
was moved to the common library (which utilized these inclusions). Since
the move, nothing requires these headers to be included within the
memory header.
- GPU will be released on shutdown, before pages are unmapped.
- On subsequent runs, current_page_table will be not nullptr, but GPU might not be valid yet.
Given this is utilized by the loaders, this allows avoiding inclusion of
the kernel process definitions where avoidable.
This also keeps the loading format for all executable data separate from
the kernel objects.
Neither the NRO or NSO loaders actually make use of the functions or
members provided by the Linker interface, so we can just remove the
inheritance altogether.
This function passes in the desired main applet and library applet
volume levels. We can then just pass those values back within the
relevant volume getter functions, allowing us to unstub those as well.
The initial values for the library and main applet volumes differ. The
main applet volume is 0.25 by default, while the library applet volume
is initialized to 1.0 by default in the services themselves.
Rather than make a global accessor for this sort of thing. We can make
it a part of the thread interface itself. This allows getting rid of a
hidden global accessor in the kernel code.
This condition was checking against the nominal thread priority, whereas
the kernel itself checks against the current priority instead. We were
also assigning the nominal priority, when we should be assigning
current_priority, which takes priority inheritance into account.
This can lead to the incorrect priority being assigned to a thread.
Given we recursively update the relevant threads, we don't need to go
through the whole mutex waiter list. This matches what the kernel does
as well (only accessing the first entry within the waiting list).
* gdbstub: fix IsMemoryBreak() returning false while connected to client
As a result, the only existing codepath for a memory watchpoint hit to break into GDB (InterpeterMainLoop, GDB_BP_CHECK, ARMul_State::RecordBreak) is finally taken,
which exposes incorrect logic* in both RecordBreak and ServeBreak.
* a blank BreakpointAddress structure is passed, which sets r15 (PC) to NULL
* gdbstub: DynCom: default-initialize two members/vars used in conditionals
* gdbstub: DynCom: don't record memory watchpoint hits via RecordBreak()
For now, instead check for GDBStub::IsMemoryBreak() in InterpreterMainLoop and ServeBreak.
Fixes PC being set to a stale/unhit breakpoint address (often zero) when a memory watchpoint (rwatch, watch, awatch) is handled in ServeBreak() and generates a GDB trap.
Reasons for removing a call to RecordBreak() for memory watchpoints:
* The``breakpoint_data`` we pass is typed Execute or None. It describes the predicted next code breakpoint hit relative to PC;
* GDBStub::IsMemoryBreak() returns true if a recent Read/Write operation hit a watchpoint. It doesn't specify which in return, nor does it trace it anywhere. Thus, the only data we could give RecordBreak() is a placeholder BreakpointAddress at offset NULL and type Access. I found the idea silly, compared to simply relying on GDBStub::IsMemoryBreak().
There is currently no measure in the code that remembers the addresses (and types) of any watchpoints that were hit by an instruction, in order to send them to GDB as "extended stop information."
I'm considering an implementation for this.
* gdbstub: Change an ASSERT to DEBUG_ASSERT
I have never seen the (Reg[15] == last_bkpt.address) assert fail in practice, even after several weeks of (locally) developping various branches around GDB. Only leave it inside Debug builds.
