Extend NvServices and implement IDirectory (#107)

* Fix alignment handling in NvHostAsGpu::AllocSpace

* Implement Ioctl{2,3} ioctls

These were added in HOS 3.0.0 in order to ease handling ioctl buffers.

* Introduce support for GPU address space remapping

* Fix nvdrv and am service bugs

Syncpoints are supposed to be allocated from ID 1, they were allocated
at 0 before. The ioctl functions were also missing from the service map

* Fix friend:u service name

* Stub NVGPU_IOCTL_CHANNEL_SET_TIMESLICE

* Stub IManagerForApplication::CheckAvailability

* Add OsFileSystem Directory support and add a size field to directory entries

The size field will be needed by the incoming HOS IDirectory support.

* Implement support for IDirectory

This is used by applications to list the contents of a directory.

* Address feedback

app/CMakeLists.txt

@@ -114,6 +114,7 @@ add_library(skyline SHARED
         ${source_DIR}/skyline/services/fssrv/IFileSystem.cpp
         ${source_DIR}/skyline/services/fssrv/IFile.cpp
         ${source_DIR}/skyline/services/fssrv/IStorage.cpp
+        ${source_DIR}/skyline/services/fssrv/IDirectory.cpp
         ${source_DIR}/skyline/services/nvdrv/INvDrvServices.cpp
         ${source_DIR}/skyline/services/nvdrv/driver.cpp
         ${source_DIR}/skyline/services/nvdrv/devices/nvdevice.cpp

app/src/main/cpp/skyline/gpu/memory_manager.cpp

@@ -14,9 +14,9 @@ namespace skyline::gpu::vmm {
         chunks.push_back(baseChunk);
     }
 
-    std::optional<ChunkDescriptor> MemoryManager::FindChunk(u64 size, ChunkState state) {
-        auto chunk{std::find_if(chunks.begin(), chunks.end(), [size, state](const ChunkDescriptor &chunk) -> bool {
-            return chunk.size > size && chunk.state == state;
+    std::optional<ChunkDescriptor> MemoryManager::FindChunk(ChunkState state, u64 size, u64 alignment) {
+        auto chunk{std::find_if(chunks.begin(), chunks.end(), [state, size, alignment](const ChunkDescriptor &chunk) -> bool {
+            return (alignment ? util::IsAligned(chunk.address, alignment) : true) && chunk.size > size && chunk.state == state;
         })};
 
         if (chunk != chunks.end())
@@ -83,9 +83,9 @@ namespace skyline::gpu::vmm {
         throw exception("Failed to insert chunk into GPU address space!");
     }
 
-    u64 MemoryManager::ReserveSpace(u64 size) {
+    u64 MemoryManager::ReserveSpace(u64 size, u64 alignment) {
         size = util::AlignUp(size, constant::GpuPageSize);
-        auto newChunk{FindChunk(size, ChunkState::Unmapped)};
+        auto newChunk{FindChunk(ChunkState::Unmapped, size, alignment)};
         if (!newChunk)
             return 0;
 
@@ -98,7 +98,7 @@ namespace skyline::gpu::vmm {
 
     u64 MemoryManager::ReserveFixed(u64 address, u64 size) {
         if (!util::IsAligned(address, constant::GpuPageSize))
-            return false;
+            return 0;
 
         size = util::AlignUp(size, constant::GpuPageSize);
 
@@ -107,7 +107,7 @@ namespace skyline::gpu::vmm {
 
     u64 MemoryManager::MapAllocate(u64 address, u64 size) {
         size = util::AlignUp(size, constant::GpuPageSize);
-        auto mappedChunk{FindChunk(size, ChunkState::Unmapped)};
+        auto mappedChunk{FindChunk(ChunkState::Unmapped, size)};
         if (!mappedChunk)
             return 0;
 
@@ -121,26 +121,22 @@ namespace skyline::gpu::vmm {
 
     u64 MemoryManager::MapFixed(u64 address, u64 cpuAddress, u64 size) {
         if (!util::IsAligned(address, constant::GpuPageSize))
-            return false;
+            return 0;
 
         size = util::AlignUp(size, constant::GpuPageSize);
 
         return InsertChunk(ChunkDescriptor(address, size, cpuAddress, ChunkState::Mapped));
     }
 
-    bool MemoryManager::Unmap(u64 address) {
+    bool MemoryManager::Unmap(u64 address, u64 size) {
         if (!util::IsAligned(address, constant::GpuPageSize))
             return false;
 
-        auto chunk{std::find_if(chunks.begin(), chunks.end(), [address](const ChunkDescriptor &chunk) -> bool {
-            return chunk.address == address;
-        })};
-
-        if (chunk == chunks.end())
+        try {
+            InsertChunk(ChunkDescriptor(address, size, 0, ChunkState::Unmapped));
+        } catch (const std::exception &e) {
             return false;
-
-        chunk->state = ChunkState::Reserved;
-        chunk->cpuAddress = 0;
+        }
 
         return true;
     }

app/src/main/cpp/skyline/gpu/memory_manager.h

@@ -43,11 +43,12 @@ namespace skyline {
 
             /**
              * @brief Finds a chunk of the specified type in the GPU address space that is larger than the given size
+             * @param state The state of the chunk to find
              * @param size The minimum size of the chunk to find
-             * @param state The state desired state of the chunk to find
-             * @return The first unmapped chunk in the GPU address space that fits the requested size
+             * @param alignment The alignment of the chunk to find
+             * @return The first unmapped chunk in the GPU address space that fulfils the requested conditions
              */
-            std::optional<ChunkDescriptor> FindChunk(u64 size, ChunkState state);
+            std::optional<ChunkDescriptor> FindChunk(ChunkState state, u64 size, u64 alignment = 0);
 
             /**
              * @brief Inserts a chunk into the chunk list, resizing and splitting as necessary
@@ -62,9 +63,10 @@ namespace skyline {
             /**
              * @brief Reserves a region of the GPU address space so it will not be chosen automatically when mapping
              * @param size The size of the region to reserve
+             * @param alignment The alignment of the region to reserve
              * @return The virtual GPU base address of the region base
              */
-            u64 ReserveSpace(u64 size);
+            u64 ReserveSpace(u64 size, u64 alignment);
 
             /**
              * @brief Reserves a fixed region of the GPU address space so it will not be chosen automatically when mapping
@@ -92,10 +94,10 @@ namespace skyline {
             u64 MapFixed(u64 address, u64 cpuAddress, u64 size);
 
             /**
-             * @brief Unmaps the chunk that starts at 'offset' from the GPU address space
+             * @brief Unmaps all chunks in the given region from the GPU address space
              * @return Whether the operation succeeded
              */
-            bool Unmap(u64 address);
+            bool Unmap(u64 address, u64 size);
 
             void Read(u8 *destination, u64 address, u64 size) const;
 

app/src/main/cpp/skyline/services/account/IManagerForApplication.cpp

@@ -5,4 +5,8 @@
 
 namespace skyline::service::account {
     IManagerForApplication::IManagerForApplication(const DeviceState &state, ServiceManager &manager) : BaseService(state, manager) {}
+
+    Result IManagerForApplication::CheckAvailability(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
+        return {};
+    }
 }

app/src/main/cpp/skyline/services/account/IManagerForApplication.h

@@ -13,5 +13,14 @@ namespace skyline::service::account {
     class IManagerForApplication : public BaseService {
       public:
         IManagerForApplication(const DeviceState &state, ServiceManager &manager);
+
+        /**
+        * @brief This checks if the given user has access to online services
+        */
+        Result CheckAvailability(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
+
+        SERVICE_DECL(
+            SFUNC(0x0, IManagerForApplication, CheckAvailability)
+        )
     };
-}
+}

app/src/main/cpp/skyline/services/am/storage/IStorageAccessor.cpp

@@ -27,7 +27,7 @@ namespace skyline::service::am {
 
     Result IStorageAccessor::Read(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
         auto offset{request.Pop<i64>()};
-        auto size{std::min(static_cast<i64>(request.inputBuf.at(0).size()), static_cast<i64>(parent->content.size()) - offset)};
+        auto size{std::min(static_cast<i64>(request.outputBuf.at(0).size()), static_cast<i64>(parent->content.size()) - offset)};
 
         if (offset > parent->content.size())
             return result::OutOfBounds;

app/src/main/cpp/skyline/services/fssrv/IDirectory.cpp

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#include <kernel/types/KProcess.h>
+#include "results.h"
+#include "IDirectory.h"
+
+namespace skyline::service::fssrv {
+    struct __attribute__((packed)) DirectoryEntry {
+        std::array<char, 0x301> name;
+
+        struct {
+            bool directory : 1;
+            bool archive : 1;
+            u8 _pad_ : 6;
+        } attributes;
+
+        u16 _pad0_;
+        vfs::Directory::EntryType type;
+        u8 _pad1_[3];
+        u64 size;
+    };
+
+    IDirectory::IDirectory(std::shared_ptr<vfs::Directory> backing, std::shared_ptr<vfs::FileSystem> backingFs, const DeviceState &state, ServiceManager &manager) : backing(backing), backingFs(backingFs), BaseService(state, manager) {}
+
+    Result IDirectory::Read(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
+        auto entries{backing->Read()};
+        auto outputEntries{request.inputBuf.at(0).cast<DirectoryEntry>()};
+        size_t i{};
+
+        for (; i < std::min(entries.size(), outputEntries.size()); i++) {
+            auto &entry{entries.at(i)};
+
+            outputEntries[i] = {
+                .type = entry.type,
+                .attributes.directory = (entry.type == vfs::Directory::EntryType::Directory),
+                .size = entry.size,
+            };
+
+            span(outputEntries[i].name).copy_from(entry.name);
+        }
+
+        response.Push<u64>(i);
+        return {};
+    }
+}

app/src/main/cpp/skyline/services/fssrv/IDirectory.h

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#pragma once
+
+#include <services/base_service.h>
+#include <services/serviceman.h>
+#include <vfs/directory.h>
+#include <vfs/filesystem.h>
+
+namespace skyline::service::fssrv {
+    /**
+     * @brief IDirectory is an interface for accessing directory contents
+     * @url https://switchbrew.org/wiki/Filesystem_services#IDirectory
+     */
+    class IDirectory : public BaseService {
+      private:
+        std::shared_ptr<vfs::Directory> backing; //!< Backing directory of the IDirectory
+        std::shared_ptr<vfs::FileSystem> backingFs; //!< Backing filesystem of the IDirectory
+
+      public:
+        IDirectory(std::shared_ptr<vfs::Directory> backing, std::shared_ptr<vfs::FileSystem> backingFs, const DeviceState &state, ServiceManager &manager);
+
+        /**
+         * @brief Reads the contents of an IDirectory
+         */
+        Result Read(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
+
+        SERVICE_DECL(
+            SFUNC(0x0, IDirectory, Read),
+        )
+    };
+}

app/src/main/cpp/skyline/services/fssrv/IFileSystem.cpp

@@ -3,13 +3,14 @@
 
 #include "results.h"
 #include "IFile.h"
+#include "IDirectory.h"
 #include "IFileSystem.h"
 
 namespace skyline::service::fssrv {
     IFileSystem::IFileSystem(std::shared_ptr<vfs::FileSystem> backing, const DeviceState &state, ServiceManager &manager) : backing(backing), BaseService(state, manager) {}
 
     Result IFileSystem::CreateFile(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
-        std::string path{request.inputBuf.at(0).as<char>()};
+        std::string path(request.inputBuf.at(0).as_string(true));
         auto mode{request.Pop<u64>()};
         auto size{request.Pop<u32>()};
 
@@ -17,7 +18,7 @@ namespace skyline::service::fssrv {
     }
 
     Result IFileSystem::GetEntryType(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
-        std::string path{request.inputBuf.at(0).as<char>()};
+        std::string path(request.inputBuf.at(0).as_string(true));
 
         auto type{backing->GetEntryType(path)};
 
@@ -31,7 +32,7 @@ namespace skyline::service::fssrv {
     }
 
     Result IFileSystem::OpenFile(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
-        std::string path{request.inputBuf.at(0).as<char>()};
+        std::string path(request.inputBuf.at(0).as_string(true));
         auto mode{request.Pop<vfs::Backing::Mode>()};
 
         if (!backing->FileExists(path))
@@ -46,6 +47,19 @@ namespace skyline::service::fssrv {
         return {};
     }
 
+    Result IFileSystem::OpenDirectory(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
+        std::string path(request.inputBuf.at(0).as_string(true));
+
+        if (!path.ends_with("/"))
+            path += "/";
+
+        auto listMode{request.Pop<vfs::Directory::ListMode>()};
+        auto directory{backing->OpenDirectory(path, listMode)};
+
+        manager.RegisterService(std::make_shared<IDirectory>(directory, backing, state, manager), session, response);
+        return {};
+    }
+
     Result IFileSystem::Commit(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response) {
         return {};
     }

app/src/main/cpp/skyline/services/fssrv/IFileSystem.h

@@ -35,6 +35,11 @@ namespace skyline::service::fssrv {
          */
         Result OpenFile(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
 
+        /**
+         * @brief This returns an IDirectory handle for the requested path and mask (https://switchbrew.org/wiki/Filesystem_services#OpenDirectory)
+         */
+        Result OpenDirectory(type::KSession &session, ipc::IpcRequest &request, ipc::IpcResponse &response);
+
         /**
          * @brief Commits all changes to the filesystem
          * @url https://switchbrew.org/wiki/Filesystem_services#Commit
@@ -45,6 +50,7 @@ namespace skyline::service::fssrv {
             SFUNC(0x0, IFileSystem, CreateFile),
             SFUNC(0x7, IFileSystem, GetEntryType),
             SFUNC(0x8, IFileSystem, OpenFile),
+            SFUNC(0x9, IFileSystem, OpenDirectory),
             SFUNC(0xA, IFileSystem, Commit)
         )
     };

app/src/main/cpp/skyline/services/nvdrv/INvDrvServices.h

@@ -80,6 +80,8 @@ namespace skyline::service::nvdrv {
             SFUNC(0x3, INvDrvServices, Initialize),
             SFUNC(0x4, INvDrvServices, QueryEvent),
             SFUNC(0x8, INvDrvServices, SetAruid),
+            SFUNC(0xB, INvDrvServices, Ioctl2),
+            SFUNC(0xC, INvDrvServices, Ioctl3),
             SFUNC(0xD, INvDrvServices, SetGraphicsFirmwareMemoryMarginEnabled)
         )
     };

app/src/main/cpp/skyline/services/nvdrv/devices/nvdevice.h

@@ -78,7 +78,7 @@ namespace skyline::service::nvdrv::device {
          * @return The name of the class
          * @note The lifetime of the returned string is tied to that of the class
          */
-        const std::string& GetName();
+        const std::string &GetName();
 
         /**
          * @brief Handles IOCTL calls for devices

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_as_gpu.cpp

@@ -7,6 +7,14 @@
 #include "nvhost_as_gpu.h"
 
 namespace skyline::service::nvdrv::device {
+    struct MappingFlags {
+        bool fixed : 1;
+        u8 _pad0_ : 7;
+        bool remap : 1;
+        u32 _pad1_ : 23;
+    };
+    static_assert(sizeof(MappingFlags) == sizeof(u32));
+
     NvHostAsGpu::NvHostAsGpu(const DeviceState &state) : NvDevice(state) {}
 
     NvStatus NvHostAsGpu::BindChannel(IoctlType type, span<u8> buffer, span<u8> inlineBuffer) {
@@ -15,22 +23,22 @@ namespace skyline::service::nvdrv::device {
 
     NvStatus NvHostAsGpu::AllocSpace(IoctlType type, span<u8> buffer, span<u8> inlineBuffer) {
         struct Data {
-            u32 pages;      // In
-            u32 pageSize;   // In
-            u32 flags;      // In
+            u32 pages;          // In
+            u32 pageSize;       // In
+            MappingFlags flags; // In
             u32 _pad_;
             union {
-                u64 offset; // InOut
-                u64 align;  // In
+                u64 offset;     // InOut
+                u64 align;      // In
             };
-        } region = buffer.as<Data>();
+        } &region = buffer.as<Data>();
 
         u64 size{static_cast<u64>(region.pages) * static_cast<u64>(region.pageSize)};
 
-        if (region.flags & 1)
+        if (region.flags.fixed)
             region.offset = state.gpu->memoryManager.ReserveFixed(region.offset, size);
         else
-            region.offset = state.gpu->memoryManager.ReserveSpace(size);
+            region.offset = state.gpu->memoryManager.ReserveSpace(size, region.align);
 
         if (region.offset == 0) {
             state.logger->Warn("Failed to allocate GPU address space region!");
@@ -43,32 +51,67 @@ namespace skyline::service::nvdrv::device {
     NvStatus NvHostAsGpu::UnmapBuffer(IoctlType type, span<u8> buffer, span<u8> inlineBuffer) {
         u64 offset{buffer.as<u64>()};
 
-        if (!state.gpu->memoryManager.Unmap(offset))
-            state.logger->Warn("Failed to unmap chunk at 0x{:X}", offset);
+        try {
+            auto region{regionMap.at(offset)};
+
+            // Non-fixed regions are unmapped so that they can be used by future non-fixed mappings
+            if (!region.fixed)
+                if (!state.gpu->memoryManager.Unmap(offset, region.size))
+                    state.logger->Warn("Failed to unmap region at 0x{:X}", offset);
+
+            regionMap.erase(offset);
+        } catch (const std::out_of_range &e) {
+            state.logger->Warn("Couldn't find region to unmap at 0x{:X}", offset);
+        }
 
         return NvStatus::Success;
     }
 
     NvStatus NvHostAsGpu::Modify(IoctlType type, span<u8> buffer, span<u8> inlineBuffer) {
         struct Data {
-            u32 flags;        // In
-            u32 kind;         // In
-            u32 nvmapHandle;  // In
-            u32 pageSize;     // InOut
-            u64 bufferOffset; // In
-            u64 mappingSize;  // In
-            u64 offset;       // InOut
-        }  &data = buffer.as<Data>();
+            MappingFlags flags; // In
+            u32 kind;           // In
+            u32 nvmapHandle;    // In
+            u32 pageSize;       // InOut
+            u64 bufferOffset;   // In
+            u64 mappingSize;    // In
+            u64 offset;         // InOut
+        } &data = buffer.as<Data>();
 
         try {
             auto driver{nvdrv::driver.lock()};
             auto nvmap{driver->nvMap.lock()};
             auto mapping{nvmap->handleTable.at(data.nvmapHandle)};
 
+            if (data.flags.remap) {
+                auto region{regionMap.upper_bound(data.offset)};
+                if ((region == regionMap.begin()) || (region == regionMap.end())) {
+                    state.logger->Warn("Cannot remap an unmapped GPU address space region: 0x{:X}", data.offset);
+                    return NvStatus::BadParameter;
+                }
+
+                region--; // Upper bound gives us the region after the one we want
+
+                if (region->second.size < data.mappingSize) {
+                    state.logger->Warn("Cannot remap an partially mapped GPU address space region: 0x{:X}", data.offset);
+                    return NvStatus::BadParameter;
+                }
+
+                u64 gpuAddress{data.offset + data.bufferOffset};
+                u64 cpuAddress{region->second.cpuAddress + data.bufferOffset};
+
+                if (state.gpu->memoryManager.MapFixed(gpuAddress, cpuAddress, data.mappingSize)) {
+                    state.logger->Warn("Failed to remap GPU address space region: 0x{:X}", gpuAddress);
+                    return NvStatus::BadParameter;
+                }
+
+                return NvStatus::Success;
+            }
+
             u64 mapPhysicalAddress{data.bufferOffset + mapping->address};
             u64 mapSize{data.mappingSize ? data.mappingSize : mapping->size};
 
-            if (data.flags & 1)
+            if (data.flags.fixed)
                 data.offset = state.gpu->memoryManager.MapFixed(data.offset, mapPhysicalAddress, mapSize);
             else
                 data.offset = state.gpu->memoryManager.MapAllocate(mapPhysicalAddress, mapSize);
@@ -78,6 +121,8 @@ namespace skyline::service::nvdrv::device {
                 return NvStatus::BadParameter;
             }
 
+            regionMap[data.offset] = {mapPhysicalAddress, mapSize, data.flags.fixed};
+
             return NvStatus::Success;
         } catch (const std::out_of_range &) {
             state.logger->Warn("Invalid NvMap handle: 0x{:X}", data.nvmapHandle);

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_as_gpu.h

@@ -11,6 +11,15 @@ namespace skyline::service::nvdrv::device {
      * @url https://switchbrew.org/wiki/NV_services#.2Fdev.2Fnvhost-as-gpu
      */
     class NvHostAsGpu : public NvDevice {
+      private:
+        struct AddressSpaceRegion {
+            u64 cpuAddress;
+            u64 size;
+            bool fixed;
+        };
+
+        std::map<u64, AddressSpaceRegion> regionMap; //!< This maps the base addresses of mapped buffers to their total sizes and mapping type, this is needed as what was originally a single buffer may have been split into multiple GPU side buffers with the remap flag.
+
       public:
         NvHostAsGpu(const DeviceState &state);
 

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_channel.cpp

@@ -54,7 +54,12 @@ namespace skyline::service::nvdrv::device {
                 throw exception("Waiting on a fence through SubmitGpfifo is unimplemented");
         }
 
-        state.gpu->gpfifo.Push(span(state.process->GetPointer<gpu::gpfifo::GpEntry>(data.address), data.numEntries));
+        state.gpu->gpfifo.Push([&]() {
+            if (type == IoctlType::Ioctl2)
+                return inlineBuffer.cast<gpu::gpfifo::GpEntry>();
+            else
+                return span(state.process->GetPointer<gpu::gpfifo::GpEntry>(data.address), data.numEntries);
+        }());
 
         data.fence.id = channelFence.id;
 
@@ -113,6 +118,10 @@ namespace skyline::service::nvdrv::device {
         return NvStatus::Success;
     }
 
+    NvStatus NvHostChannel::SetTimeslice(IoctlType type, std::span<u8> buffer, std::span<u8> inlineBuffer) {
+        return NvStatus::Success;
+    }
+
     NvStatus NvHostChannel::SetUserData(IoctlType type, span<u8> buffer, span<u8> inlineBuffer) {
         return NvStatus::Success;
     }

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_channel.h

@@ -76,6 +76,12 @@ namespace skyline::service::nvdrv::device {
          */
         NvStatus AllocGpfifoEx2(IoctlType type, span<u8> buffer, span<u8> inlineBuffer);
 
+        /**
+         * @brief Sets the timeslice of the channel
+         * @url https://switchbrew.org/wiki/NV_services#NVGPU_IOCTL_CHANNEL_SET_TIMESLICE)
+         */
+        NvStatus SetTimeslice(IoctlType type, std::span<u8> buffer, std::span<u8> inlineBuffer);
+
         /**
          * @brief Sets the user specific data
          * @url https://switchbrew.org/wiki/NV_services#NVGPU_IOCTL_CHANNEL_SET_USER_DATA
@@ -93,6 +99,7 @@ namespace skyline::service::nvdrv::device {
             NVFUNC(0x480C, NvHostChannel, SetErrorNotifier),
             NVFUNC(0x480D, NvHostChannel, SetPriority),
             NVFUNC(0x481A, NvHostChannel, AllocGpfifoEx2),
+            NVFUNC(0x481B, NvHostChannel, SubmitGpfifo), // Our SubmitGpfifo implementation also handles SubmitGpfifoEx
             NVFUNC(0x4714, NvHostChannel, SetUserData)
         )
     };

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_ctrl.cpp

@@ -112,7 +112,7 @@ namespace skyline::service::nvdrv::device {
             userEventId = FindFreeEvent(data.fence.id);
         }
 
-        auto& event{*events.at(userEventId)};
+        auto &event{*events.at(userEventId)};
         if (event.state == NvHostEvent::State::Cancelled || event.state == NvHostEvent::State::Available || event.state == NvHostEvent::State::Signaled) {
             state.logger->Debug("Now waiting on nvhost event: {} with fence: {}", userEventId, data.fence.id);
             event.Wait(state.gpu, data.fence);

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_ctrl_gpu.cpp

@@ -77,7 +77,13 @@ namespace skyline::service::nvdrv::device {
         if (data.gpuCharacteristicsBufSize < sizeof(GpuCharacteristics))
             return NvStatus::InvalidSize;
 
-        data.gpuCharacteristics = GpuCharacteristics{};
+        // The IOCTL3 version of GetCharacteristics additionally outputs to the inline output buffer
+        if (type == IoctlType::Ioctl3) {
+            auto &inlineCharacteristics{inlineBuffer.as<GpuCharacteristics>()};
+            data.gpuCharacteristics = inlineCharacteristics = GpuCharacteristics{};
+        } else {
+            data.gpuCharacteristics = GpuCharacteristics{};
+        }
         data.gpuCharacteristicsBufSize = sizeof(GpuCharacteristics);
 
         return NvStatus::Success;
@@ -90,8 +96,14 @@ namespace skyline::service::nvdrv::device {
             u64 maskBuf;     // Out
         } &data = buffer.as<Data>();
 
-        if (data.maskBufSize)
-            data.maskBuf = 0x3;
+        if (data.maskBufSize) {
+            if (type == IoctlType::Ioctl3) {
+                auto &inlineMask{inlineBuffer.as<u32>()};
+                data.maskBuf = inlineMask = 0x3;
+            } else {
+                data.maskBuf = 0x3;
+            }
+        }
 
         return NvStatus::Success;
     }

app/src/main/cpp/skyline/services/nvdrv/devices/nvhost_syncpoint.cpp

@@ -28,7 +28,7 @@ namespace skyline::service::nvdrv {
     }
 
     u32 NvHostSyncpoint::FindFreeSyncpoint() {
-        for (u32 i{}; i < constant::MaxHwSyncpointCount; i++)
+        for (u32 i{1}; i < constant::MaxHwSyncpointCount; i++)
             if (!syncpoints[i].reserved)
                 return i;
 

app/src/main/cpp/skyline/services/serviceman.cpp

@@ -73,7 +73,7 @@ namespace skyline::service {
             SERVICE_CASE(pctl::IParentalControlServiceFactory, "pctl:r")
             SERVICE_CASE(lm::ILogService, "lm")
             SERVICE_CASE(account::IAccountServiceForApplication, "acc:u0")
-            SERVICE_CASE(friends::IServiceCreator, "friend")
+            SERVICE_CASE(friends::IServiceCreator, "friend:u")
             SERVICE_CASE(nfp::IUserManager, "nfp:user")
             SERVICE_CASE(nifm::IStaticService, "nifm:u")
             SERVICE_CASE(socket::IClient, "bsd:u")

app/src/main/cpp/skyline/vfs/directory.h

@@ -19,6 +19,7 @@ namespace skyline::vfs {
         struct Entry {
             std::string name;
             EntryType type;
+            size_t size; //!< 0 if a directory
         };
 
         /**
@@ -29,7 +30,7 @@ namespace skyline::vfs {
                 bool directory : 1; //!< The directory listing will contain subdirectories
                 bool file : 1; //!< The directory listing will contain files
             };
-            u32 raw;
+            u32 raw{};
         };
         static_assert(sizeof(ListMode) == 0x4);
 

app/src/main/cpp/skyline/vfs/os_filesystem.cpp

@@ -3,7 +3,6 @@
 
 #include <sys/stat.h>
 #include <fcntl.h>
-
 #include <dirent.h>
 #include <unistd.h>
 #include "os_backing.h"
@@ -84,4 +83,45 @@ namespace skyline::vfs {
 
         return std::nullopt;
     }
+
+    std::shared_ptr<Directory> OsFileSystem::OpenDirectory(const std::string &path, Directory::ListMode listMode) {
+        return std::make_shared<OsFileSystemDirectory>(basePath + path, listMode);
+    }
+
+    OsFileSystemDirectory::OsFileSystemDirectory(const std::string &path, Directory::ListMode listMode) : Directory(listMode), path(path) {}
+
+    std::vector<Directory::Entry> OsFileSystemDirectory::Read() {
+        if (!listMode.file && !listMode.directory)
+            return {};
+
+        std::vector<Directory::Entry> outputEntries;
+
+        struct dirent *entry;
+        auto directory{opendir(path.c_str())};
+        if (!directory)
+            throw exception("Failed to open directory: {}, error: {}", path, strerror(errno));
+
+        while ((entry = readdir(directory))) {
+            struct stat entryInfo;
+            if (stat((path + std::string(entry->d_name)).c_str(), &entryInfo))
+                throw exception("Failed to stat directory entry: {}, error: {}", entry->d_name, strerror(errno));
+
+            std::string name(entry->d_name);
+            if (S_ISDIR(entryInfo.st_mode) && listMode.directory && (name != ".") && (name != "..")) {
+                outputEntries.push_back(Directory::Entry{
+                    .type = Directory::EntryType::Directory,
+                    .name = std::string(entry->d_name),
+                    .size = 0,
+                });
+            } else if (S_ISREG(entryInfo.st_mode) && listMode.file) {
+                outputEntries.push_back(Directory::Entry{
+                    .type = Directory::EntryType::File,
+                    .name = std::string(entry->d_name),
+                    .size = static_cast<size_t>(entryInfo.st_size),
+                });
+            }
+        }
+
+        return outputEntries;
+    }
 }

app/src/main/cpp/skyline/vfs/os_filesystem.h

@@ -23,5 +23,19 @@ namespace skyline::vfs {
         std::shared_ptr<Backing> OpenFile(const std::string &path, Backing::Mode mode = {true, false, false});
 
         std::optional<Directory::EntryType> GetEntryType(const std::string &path);
+
+        std::shared_ptr<Directory> OpenDirectory(const std::string &path, Directory::ListMode listMode);
     };
-}
+
+    /**
+     * @brief OsFileSystemDirectory abstracts access to a native linux directory through the VFS APIs
+     */
+    class OsFileSystemDirectory : public Directory {
+      private:
+        std::string path;
+
+      public:
+        OsFileSystemDirectory(const std::string &path, ListMode listMode);
+
+        std::vector<Entry> Read();
+    };}

app/src/main/cpp/skyline/vfs/partition_filesystem.cpp

@@ -54,7 +54,7 @@ namespace skyline::vfs {
 
         std::vector<Directory::Entry> fileList;
         for (const auto &file : fileMap)
-            fileList.emplace_back(Directory::Entry{file.first, Directory::EntryType::File});
+            fileList.emplace_back(Directory::Entry{file.first, Directory::EntryType::File, file.second.size});
 
         return std::make_shared<PartitionFileSystemDirectory>(fileList, listMode);
     }

app/src/main/cpp/skyline/vfs/region_backing.h

@@ -22,7 +22,7 @@ namespace skyline::vfs {
          */
         RegionBacking(const std::shared_ptr<vfs::Backing> &backing, size_t offset, size_t size, Mode mode = {true, false, false}) : Backing(mode, size), backing(backing), baseOffset(offset) {};
 
-        virtual size_t Read(span<u8> output, size_t offset = 0) {
+        size_t Read(span<u8> output, size_t offset = 0) {
             if (!mode.read)
                 throw exception("Attempting to read a backing that is not readable");
             if (size - offset < output.size())

app/src/main/cpp/skyline/vfs/rom_filesystem.cpp

@@ -92,7 +92,7 @@ namespace skyline::vfs {
                     std::vector<char> name(romFsFileEntry.nameSize);
                     backing->Read(span(name).cast<u8>(), header.fileMetaTableOffset + offset + sizeof(RomFileSystem::RomFsFileEntry));
 
-                    contents.emplace_back(Entry{std::string(name.data(), romFsFileEntry.nameSize), EntryType::File});
+                    contents.emplace_back(Entry{std::string(name.data(), romFsFileEntry.nameSize), EntryType::File, romFsFileEntry.size});
                 }
 
                 offset = romFsFileEntry.siblingOffset;