Add /dev/dolphin for homebrew to get information about Dolphin

Adds a /dev/dolphin interface that can be used by
Dolphin-aware software to get information like the
real system time and the Dolphin version.

Source/Core/Core/IOS/DolphinDevice.cpp

@@ -0,0 +1,151 @@
+// Copyright 2019 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <cstring>
+
+#include "Common/Logging/Log.h"
+#include "Common/Timer.h"
+#include "Common/scmrev.h"
+#include "Core/BootManager.h"
+#include "Core/ConfigManager.h"
+#include "Core/Core.h"
+#include "Core/HW/Memmap.h"
+#include "Core/IOS/DolphinDevice.h"
+
+namespace IOS::HLE::Device
+{
+namespace
+{
+enum
+{
+  IOCTL_DOLPHIN_GET_SYSTEM_TIME = 0x01,
+  IOCTL_DOLPHIN_GET_VERSION = 0x02,
+  IOCTL_DOLPHIN_GET_SPEED_LIMIT = 0x03,
+  IOCTL_DOLPHIN_SET_SPEED_LIMIT = 0x04,
+  IOCTL_DOLPHIN_GET_CPU_SPEED = 0x05,
+
+};
+
+IPCCommandResult GetSystemTime(const IOCtlVRequest& request)
+{
+  if (!request.HasNumberOfValidVectors(0, 1))
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  if (request.io_vectors[0].size != 4)
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  const u32 milliseconds = Common::Timer::GetTimeMs();
+
+  Memory::Write_U32(milliseconds, request.io_vectors[0].address);
+  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+}
+
+IPCCommandResult GetVersion(const IOCtlVRequest& request)
+{
+  if (!request.HasNumberOfValidVectors(0, 1))
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  const auto length = std::min(size_t(request.io_vectors[0].size), std::strlen(SCM_DESC_STR));
+
+  Memory::Memset(request.io_vectors[0].address, 0, request.io_vectors[0].size);
+  Memory::CopyToEmu(request.io_vectors[0].address, SCM_DESC_STR, length);
+
+  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+}
+
+IPCCommandResult GetCPUSpeed(const IOCtlVRequest& request)
+{
+  if (!request.HasNumberOfValidVectors(0, 1))
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  if (request.io_vectors[0].size != 4)
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  const SConfig& config = SConfig::GetInstance();
+  const float oc = config.m_OCEnable ? config.m_OCFactor : 1.0f;
+
+  const u32 core_clock = u32(float(SystemTimers::GetTicksPerSecond()) * oc);
+
+  Memory::Write_U32(core_clock, request.io_vectors[0].address);
+
+  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+}
+
+IPCCommandResult GetSpeedLimit(const IOCtlVRequest& request)
+{
+  // get current speed limit
+  if (!request.HasNumberOfValidVectors(0, 1))
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  if (request.io_vectors[0].size != 4)
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  const SConfig& config = SConfig::GetInstance();
+  const u32 speed_percent = config.m_EmulationSpeed * 100;
+  Memory::Write_U32(speed_percent, request.io_vectors[0].address);
+
+  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+}
+
+IPCCommandResult SetSpeedLimit(const IOCtlVRequest& request)
+{
+  // set current speed limit
+  if (!request.HasNumberOfValidVectors(1, 0))
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  if (request.in_vectors[0].size != 4)
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EINVAL);
+  }
+
+  const float speed = float(Memory::Read_U32(request.in_vectors[0].address)) / 100.0f;
+  SConfig::GetInstance().m_EmulationSpeed = speed;
+  BootManager::SetEmulationSpeedReset(true);
+
+  return DolphinDevice::GetDefaultReply(IPC_SUCCESS);
+}
+
+}  // namespace
+
+IPCCommandResult DolphinDevice::IOCtlV(const IOCtlVRequest& request)
+{
+  if (Core::WantsDeterminism())
+  {
+    return DolphinDevice::GetDefaultReply(IPC_EACCES);
+  }
+
+  switch (request.request)
+  {
+  case IOCTL_DOLPHIN_GET_SYSTEM_TIME:
+    return GetSystemTime(request);
+  case IOCTL_DOLPHIN_GET_VERSION:
+    return GetVersion(request);
+  case IOCTL_DOLPHIN_GET_SPEED_LIMIT:
+    return GetSpeedLimit(request);
+  case IOCTL_DOLPHIN_SET_SPEED_LIMIT:
+    return SetSpeedLimit(request);
+  case IOCTL_DOLPHIN_GET_CPU_SPEED:
+    return GetCPUSpeed(request);
+  default:
+    return GetDefaultReply(IPC_EINVAL);
+  }
+}
+}  // namespace IOS::HLE::Device