yuzu/src/core/hle/kernel/session.h
2014-12-20 21:20:24 -08:00

59 lines
2.5 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include "core/hle/kernel/kernel.h"
namespace Kernel {
static const int kCommandHeaderOffset = 0x80; ///< Offset into command buffer of header
/**
* Returns a pointer to the command buffer in kernel memory
* @param offset Optional offset into command buffer
* @return Pointer to command buffer
*/
inline static u32* GetCommandBuffer(const int offset=0) {
return (u32*)Memory::GetPointer(Memory::KERNEL_MEMORY_VADDR + kCommandHeaderOffset + offset);
}
/**
* Kernel object representing the client endpoint of an IPC session. Sessions are the basic CTR-OS
* primitive for communication between different processes, and are used to implement service calls
* to the various system services.
*
* To make a service call, the client must write the command header and parameters to the buffer
* located at offset 0x80 of the TLS (Thread-Local Storage) area, then execute a SendSyncRequest
* SVC call with its Session handle. The kernel will read the command header, using it to marshall
* the parameters to the process at the server endpoint of the session. After the server replies to
* the request, the response is marshalled back to the caller's TLS buffer and control is
* transferred back to it.
*
* In Citra, only the client endpoint is currently implemented and only HLE calls, where the IPC
* request is answered by C++ code in the emulator, are supported. When SendSyncRequest is called
* with the session handle, this class's SyncRequest method is called, which should read the TLS
* buffer and emulate the call accordingly. Since the code can directly read the emulated memory,
* no parameter marshalling is done.
*
* In the long term, this should be turned into the full-fledged IPC mechanism implemented by
* CTR-OS so that IPC calls can be optionally handled by the real implementations of processes, as
* opposed to HLE simulations.
*/
class Session : public Object {
public:
std::string GetTypeName() const override { return "Session"; }
static Kernel::HandleType GetStaticHandleType() { return Kernel::HandleType::Session; }
Kernel::HandleType GetHandleType() const override { return Kernel::HandleType::Session; }
/**
* Handles a synchronous call to this session using HLE emulation. Emulated <-> emulated calls
* aren't supported yet.
*/
virtual ResultVal<bool> SyncRequest() = 0;
};
}