41 files changed, 786 insertions, 478 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 753f55ebe..293d9647b 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -490,6 +490,10 @@ add_library(core STATIC
     hle/service/filesystem/fsp_pr.h
     hle/service/filesystem/fsp_srv.cpp
     hle/service/filesystem/fsp_srv.h
+    hle/service/filesystem/romfs_controller.cpp
+    hle/service/filesystem/romfs_controller.h
+    hle/service/filesystem/save_data_controller.cpp
+    hle/service/filesystem/save_data_controller.h
     hle/service/fgm/fgm.cpp
     hle/service/fgm/fgm.h
     hle/service/friend/friend.cpp
diff --git a/src/core/arm/nce/patcher.cpp b/src/core/arm/nce/patcher.cpp
index 47a7a8880..c7285e3a0 100644
--- a/src/core/arm/nce/patcher.cpp
+++ b/src/core/arm/nce/patcher.cpp
@@ -22,14 +22,10 @@ using NativeExecutionParameters = Kernel::KThread::NativeExecutionParameters;
 constexpr size_t MaxRelativeBranch = 128_MiB;
 constexpr u32 ModuleCodeIndex = 0x24 / sizeof(u32);
 
-Patcher::Patcher() : c(m_patch_instructions) {}
-
-Patcher::~Patcher() = default;
-
-void Patcher::PatchText(const Kernel::PhysicalMemory& program_image,
-                        const Kernel::CodeSet::Segment& code) {
-    // Branch to the first instruction of the module.
-    this->BranchToModule(0);
+Patcher::Patcher() : c(m_patch_instructions) {
+    // The first word of the patch section is always a branch to the first instruction of the
+    // module.
+    c.dw(0);
 
     // Write save context helper function.
     c.l(m_save_context);
@@ -38,6 +34,25 @@ void Patcher::PatchText(const Kernel::PhysicalMemory& program_image,
     // Write load context helper function.
     c.l(m_load_context);
     WriteLoadContext();
+}
+
+Patcher::~Patcher() = default;
+
+bool Patcher::PatchText(const Kernel::PhysicalMemory& program_image,
+                        const Kernel::CodeSet::Segment& code) {
+    // If we have patched modules but cannot reach the new module, then it needs its own patcher.
+    const size_t image_size = program_image.size();
+    if (total_program_size + image_size > MaxRelativeBranch && total_program_size > 0) {
+        return false;
+    }
+
+    // Add a new module patch to our list
+    modules.emplace_back();
+    curr_patch = &modules.back();
+
+    // The first word of the patch section is always a branch to the first instruction of the
+    // module.
+    curr_patch->m_branch_to_module_relocations.push_back({0, 0});
 
     // Retrieve text segment data.
     const auto text = std::span{program_image}.subspan(code.offset, code.size);
@@ -94,16 +109,17 @@ void Patcher::PatchText(const Kernel::PhysicalMemory& program_image,
         }
 
         if (auto exclusive = Exclusive{inst}; exclusive.Verify()) {
-            m_exclusives.push_back(i);
+            curr_patch->m_exclusives.push_back(i);
         }
     }
 
     // Determine patching mode for the final relocation step
-    const size_t image_size = program_image.size();
+    total_program_size += image_size;
     this->mode = image_size > MaxRelativeBranch ? PatchMode::PreText : PatchMode::PostData;
+    return true;
 }
 
-void Patcher::RelocateAndCopy(Common::ProcessAddress load_base,
+bool Patcher::RelocateAndCopy(Common::ProcessAddress load_base,
                               const Kernel::CodeSet::Segment& code,
                               Kernel::PhysicalMemory& program_image,
                               EntryTrampolines* out_trampolines) {
@@ -120,7 +136,7 @@ void Patcher::RelocateAndCopy(Common::ProcessAddress load_base,
         if (mode == PatchMode::PreText) {
             rc.B(rel.patch_offset - patch_size - rel.module_offset);
         } else {
-            rc.B(image_size - rel.module_offset + rel.patch_offset);
+            rc.B(total_program_size - rel.module_offset + rel.patch_offset);
         }
     };
 
@@ -129,7 +145,7 @@ void Patcher::RelocateAndCopy(Common::ProcessAddress load_base,
         if (mode == PatchMode::PreText) {
             rc.B(patch_size - rel.patch_offset + rel.module_offset);
         } else {
-            rc.B(rel.module_offset - image_size - rel.patch_offset);
+            rc.B(rel.module_offset - total_program_size - rel.patch_offset);
         }
     };
 
@@ -137,7 +153,7 @@ void Patcher::RelocateAndCopy(Common::ProcessAddress load_base,
         if (mode == PatchMode::PreText) {
             return GetInteger(load_base) + patch_offset;
         } else {
-            return GetInteger(load_base) + image_size + patch_offset;
+            return GetInteger(load_base) + total_program_size + patch_offset;
         }
     };
 
@@ -150,39 +166,50 @@ void Patcher::RelocateAndCopy(Common::ProcessAddress load_base,
     };
 
     // We are now ready to relocate!
-    for (const Relocation& rel : m_branch_to_patch_relocations) {
+    auto& patch = modules[m_relocate_module_index++];
+    for (const Relocation& rel : patch.m_branch_to_patch_relocations) {
         ApplyBranchToPatchRelocation(text_words.data() + rel.module_offset / sizeof(u32), rel);
     }
-    for (const Relocation& rel : m_branch_to_module_relocations) {
+    for (const Relocation& rel : patch.m_branch_to_module_relocations) {
         ApplyBranchToModuleRelocation(m_patch_instructions.data() + rel.patch_offset / sizeof(u32),
                                       rel);
     }
 
     // Rewrite PC constants and record post trampolines
-    for (const Relocation& rel : m_write_module_pc_relocations) {
+    for (const Relocation& rel : patch.m_write_module_pc_relocations) {
         oaknut::CodeGenerator rc{m_patch_instructions.data() + rel.patch_offset / sizeof(u32)};
         rc.dx(RebasePc(rel.module_offset));
     }
-    for (const Trampoline& rel : m_trampolines) {
+    for (const Trampoline& rel : patch.m_trampolines) {
         out_trampolines->insert({RebasePc(rel.module_offset), RebasePatch(rel.patch_offset)});
     }
 
     // Cortex-A57 seems to treat all exclusives as ordered, but newer processors do not.
     // Convert to ordered to preserve this assumption.
-    for (const ModuleTextAddress i : m_exclusives) {
+    for (const ModuleTextAddress i : patch.m_exclusives) {
         auto exclusive = Exclusive{text_words[i]};
         text_words[i] = exclusive.AsOrdered();
     }
 
-    // Copy to program image
-    if (this->mode == PatchMode::PreText) {
-        std::memcpy(program_image.data(), m_patch_instructions.data(),
-                    m_patch_instructions.size() * sizeof(u32));
-    } else {
-        program_image.resize(image_size + patch_size);
-        std::memcpy(program_image.data() + image_size, m_patch_instructions.data(),
-                    m_patch_instructions.size() * sizeof(u32));
+    // Remove the patched module size from the total. This is done so total_program_size
+    // always represents the distance from the currently patched module to the patch section.
+    total_program_size -= image_size;
+
+    // Only copy to the program image of the last module
+    if (m_relocate_module_index == modules.size()) {
+        if (this->mode == PatchMode::PreText) {
+            ASSERT(image_size == total_program_size);
+            std::memcpy(program_image.data(), m_patch_instructions.data(),
+                        m_patch_instructions.size() * sizeof(u32));
+        } else {
+            program_image.resize(image_size + patch_size);
+            std::memcpy(program_image.data() + image_size, m_patch_instructions.data(),
+                        m_patch_instructions.size() * sizeof(u32));
+        }
+        return true;
     }
+
+    return false;
 }
 
 size_t Patcher::GetSectionSize() const noexcept {
@@ -322,7 +349,7 @@ void Patcher::WriteSvcTrampoline(ModuleDestLabel module_dest, u32 svc_id) {
 
     // Write the post-SVC trampoline address, which will jump back to the guest after restoring its
     // state.
-    m_trampolines.push_back({c.offset(), module_dest});
+    curr_patch->m_trampolines.push_back({c.offset(), module_dest});
 
     // Host called this location. Save the return address so we can
     // unwind the stack properly when jumping back.
diff --git a/src/core/arm/nce/patcher.h b/src/core/arm/nce/patcher.h
index c6d1608c1..a44f385e2 100644
--- a/src/core/arm/nce/patcher.h
+++ b/src/core/arm/nce/patcher.h
@@ -31,9 +31,9 @@ public:
     explicit Patcher();
     ~Patcher();
 
-    void PatchText(const Kernel::PhysicalMemory& program_image,
+    bool PatchText(const Kernel::PhysicalMemory& program_image,
                    const Kernel::CodeSet::Segment& code);
-    void RelocateAndCopy(Common::ProcessAddress load_base, const Kernel::CodeSet::Segment& code,
+    bool RelocateAndCopy(Common::ProcessAddress load_base, const Kernel::CodeSet::Segment& code,
                          Kernel::PhysicalMemory& program_image, EntryTrampolines* out_trampolines);
     size_t GetSectionSize() const noexcept;
 
@@ -61,16 +61,16 @@ private:
 
 private:
     void BranchToPatch(uintptr_t module_dest) {
-        m_branch_to_patch_relocations.push_back({c.offset(), module_dest});
+        curr_patch->m_branch_to_patch_relocations.push_back({c.offset(), module_dest});
     }
 
     void BranchToModule(uintptr_t module_dest) {
-        m_branch_to_module_relocations.push_back({c.offset(), module_dest});
+        curr_patch->m_branch_to_module_relocations.push_back({c.offset(), module_dest});
         c.dw(0);
     }
 
     void WriteModulePc(uintptr_t module_dest) {
-        m_write_module_pc_relocations.push_back({c.offset(), module_dest});
+        curr_patch->m_write_module_pc_relocations.push_back({c.offset(), module_dest});
         c.dx(0);
     }
 
@@ -84,15 +84,22 @@ private:
         uintptr_t module_offset; ///< Offset in bytes from the start of the text section.
     };
 
+    struct ModulePatch {
+        std::vector<Trampoline> m_trampolines;
+        std::vector<Relocation> m_branch_to_patch_relocations{};
+        std::vector<Relocation> m_branch_to_module_relocations{};
+        std::vector<Relocation> m_write_module_pc_relocations{};
+        std::vector<ModuleTextAddress> m_exclusives{};
+    };
+
     oaknut::VectorCodeGenerator c;
-    std::vector<Trampoline> m_trampolines;
-    std::vector<Relocation> m_branch_to_patch_relocations{};
-    std::vector<Relocation> m_branch_to_module_relocations{};
-    std::vector<Relocation> m_write_module_pc_relocations{};
-    std::vector<ModuleTextAddress> m_exclusives{};
     oaknut::Label m_save_context{};
     oaknut::Label m_load_context{};
     PatchMode mode{PatchMode::None};
+    size_t total_program_size{};
+    size_t m_relocate_module_index{};
+    std::vector<ModulePatch> modules;
+    ModulePatch* curr_patch;
 };
 
 } // namespace Core::NCE
diff --git a/src/core/core.cpp b/src/core/core.cpp
index c063f7719..461eea9c8 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -413,6 +413,7 @@ struct System::Impl {
         kernel.ShutdownCores();
         services.reset();
         service_manager.reset();
+        fs_controller.Reset();
         cheat_engine.reset();
         telemetry_session.reset();
         time_manager.Shutdown();
diff --git a/src/core/debugger/debugger.cpp b/src/core/debugger/debugger.cpp
index 0e270eb50..e86aae846 100644
--- a/src/core/debugger/debugger.cpp
+++ b/src/core/debugger/debugger.cpp
@@ -114,7 +114,7 @@ public:
     }
 
     Kernel::KThread* GetActiveThread() override {
-        return state->active_thread;
+        return state->active_thread.GetPointerUnsafe();
     }
 
 private:
@@ -147,11 +147,14 @@ private:
 
         std::scoped_lock lk{connection_lock};
 
+        // Find the process we are going to debug.
+        SetDebugProcess();
+
         // Ensure everything is stopped.
         PauseEmulation();
 
         // Set up the new frontend.
-        frontend = std::make_unique<GDBStub>(*this, system);
+        frontend = std::make_unique<GDBStub>(*this, system, debug_process.GetPointerUnsafe());
 
         // Set the new state. This will tear down any existing state.
         state = ConnectionState{
@@ -194,15 +197,20 @@ private:
             UpdateActiveThread();
 
             if (state->info.type == SignalType::Watchpoint) {
-                frontend->Watchpoint(state->active_thread, *state->info.watchpoint);
+                frontend->Watchpoint(std::addressof(*state->active_thread),
+                                     *state->info.watchpoint);
             } else {
-                frontend->Stopped(state->active_thread);
+                frontend->Stopped(std::addressof(*state->active_thread));
             }
 
             break;
         case SignalType::ShuttingDown:
             frontend->ShuttingDown();
 
+            // Release members.
+            state->active_thread.Reset(nullptr);
+            debug_process.Reset(nullptr);
+
             // Wait for emulation to shut down gracefully now.
             state->signal_pipe.close();
             state->client_socket.shutdown(boost::asio::socket_base::shutdown_both);
@@ -222,7 +230,7 @@ private:
                 stopped = true;
                 PauseEmulation();
                 UpdateActiveThread();
-                frontend->Stopped(state->active_thread);
+                frontend->Stopped(state->active_thread.GetPointerUnsafe());
                 break;
             }
             case DebuggerAction::Continue:
@@ -232,7 +240,7 @@ private:
                 MarkResumed([&] {
                     state->active_thread->SetStepState(Kernel::StepState::StepPending);
                     state->active_thread->Resume(Kernel::SuspendType::Debug);
-                    ResumeEmulation(state->active_thread);
+                    ResumeEmulation(state->active_thread.GetPointerUnsafe());
                 });
                 break;
             case DebuggerAction::StepThreadLocked: {
@@ -255,6 +263,7 @@ private:
     }
 
     void PauseEmulation() {
+        Kernel::KScopedLightLock ll{debug_process->GetListLock()};
         Kernel::KScopedSchedulerLock sl{system.Kernel()};
 
         // Put all threads to sleep on next scheduler round.
@@ -264,6 +273,9 @@ private:
     }
 
     void ResumeEmulation(Kernel::KThread* except = nullptr) {
+        Kernel::KScopedLightLock ll{debug_process->GetListLock()};
+        Kernel::KScopedSchedulerLock sl{system.Kernel()};
+
         // Wake up all threads.
         for (auto& thread : ThreadList()) {
             if (std::addressof(thread) == except) {
@@ -277,15 +289,16 @@ private:
 
     template <typename Callback>
     void MarkResumed(Callback&& cb) {
-        Kernel::KScopedSchedulerLock sl{system.Kernel()};
         stopped = false;
         cb();
     }
 
     void UpdateActiveThread() {
+        Kernel::KScopedLightLock ll{debug_process->GetListLock()};
+
         auto& threads{ThreadList()};
         for (auto& thread : threads) {
-            if (std::addressof(thread) == state->active_thread) {
+            if (std::addressof(thread) == state->active_thread.GetPointerUnsafe()) {
                 // Thread is still alive, no need to update.
                 return;
             }
@@ -293,12 +306,18 @@ private:
         state->active_thread = std::addressof(threads.front());
     }
 
+private:
+    void SetDebugProcess() {
+        debug_process = std::move(system.Kernel().GetProcessList().back());
+    }
+
     Kernel::KProcess::ThreadList& ThreadList() {
-        return system.ApplicationProcess()->GetThreadList();
+        return debug_process->GetThreadList();
     }
 
 private:
     System& system;
+    Kernel::KScopedAutoObject<Kernel::KProcess> debug_process;
     std::unique_ptr<DebuggerFrontend> frontend;
 
     boost::asio::io_context io_context;
@@ -310,7 +329,7 @@ private:
         boost::process::async_pipe signal_pipe;
 
         SignalInfo info;
-        Kernel::KThread* active_thread;
+        Kernel::KScopedAutoObject<Kernel::KThread> active_thread;
         std::array<u8, 4096> client_data;
         bool pipe_data;
     };
diff --git a/src/core/debugger/gdbstub.cpp b/src/core/debugger/gdbstub.cpp
index 4051ed4af..80091cc7e 100644
--- a/src/core/debugger/gdbstub.cpp
+++ b/src/core/debugger/gdbstub.cpp
@@ -108,9 +108,9 @@ static std::string EscapeXML(std::string_view data) {
     return escaped;
 }
 
-GDBStub::GDBStub(DebuggerBackend& backend_, Core::System& system_)
-    : DebuggerFrontend(backend_), system{system_} {
-    if (system.ApplicationProcess()->Is64Bit()) {
+GDBStub::GDBStub(DebuggerBackend& backend_, Core::System& system_, Kernel::KProcess* debug_process_)
+    : DebuggerFrontend(backend_), system{system_}, debug_process{debug_process_} {
+    if (GetProcess()->Is64Bit()) {
         arch = std::make_unique<GDBStubA64>();
     } else {
         arch = std::make_unique<GDBStubA32>();
@@ -276,7 +276,7 @@ void GDBStub::ExecuteCommand(std::string_view packet, std::vector<DebuggerAction
         const size_t size{static_cast<size_t>(strtoll(command.data() + sep, nullptr, 16))};
 
         std::vector<u8> mem(size);
-        if (system.ApplicationMemory().ReadBlock(addr, mem.data(), size)) {
+        if (GetMemory().ReadBlock(addr, mem.data(), size)) {
             // Restore any bytes belonging to replaced instructions.
             auto it = replaced_instructions.lower_bound(addr);
             for (; it != replaced_instructions.end() && it->first < addr + size; it++) {
@@ -310,8 +310,8 @@ void GDBStub::ExecuteCommand(std::string_view packet, std::vector<DebuggerAction
         const auto mem_substr{std::string_view(command).substr(mem_sep)};
         const auto mem{Common::HexStringToVector(mem_substr, false)};
 
-        if (system.ApplicationMemory().WriteBlock(addr, mem.data(), size)) {
-            Core::InvalidateInstructionCacheRange(system.ApplicationProcess(), addr, size);
+        if (GetMemory().WriteBlock(addr, mem.data(), size)) {
+            Core::InvalidateInstructionCacheRange(GetProcess(), addr, size);
             SendReply(GDB_STUB_REPLY_OK);
         } else {
             SendReply(GDB_STUB_REPLY_ERR);
@@ -353,7 +353,7 @@ void GDBStub::HandleBreakpointInsert(std::string_view command) {
     const size_t addr{static_cast<size_t>(strtoll(command.data() + addr_sep, nullptr, 16))};
     const size_t size{static_cast<size_t>(strtoll(command.data() + size_sep, nullptr, 16))};
 
-    if (!system.ApplicationMemory().IsValidVirtualAddressRange(addr, size)) {
+    if (!GetMemory().IsValidVirtualAddressRange(addr, size)) {
         SendReply(GDB_STUB_REPLY_ERR);
         return;
     }
@@ -362,22 +362,20 @@ void GDBStub::HandleBreakpointInsert(std::string_view command) {
 
     switch (type) {
     case BreakpointType::Software:
-        replaced_instructions[addr] = system.ApplicationMemory().Read32(addr);
-        system.ApplicationMemory().Write32(addr, arch->BreakpointInstruction());
-        Core::InvalidateInstructionCacheRange(system.ApplicationProcess(), addr, sizeof(u32));
+        replaced_instructions[addr] = GetMemory().Read32(addr);
+        GetMemory().Write32(addr, arch->BreakpointInstruction());
+        Core::InvalidateInstructionCacheRange(GetProcess(), addr, sizeof(u32));
         success = true;
         break;
     case BreakpointType::WriteWatch:
-        success = system.ApplicationProcess()->InsertWatchpoint(addr, size,
-                                                                Kernel::DebugWatchpointType::Write);
+        success = GetProcess()->InsertWatchpoint(addr, size, Kernel::DebugWatchpointType::Write);
         break;
     case BreakpointType::ReadWatch:
-        success = system.ApplicationProcess()->InsertWatchpoint(addr, size,
-                                                                Kernel::DebugWatchpointType::Read);
+        success = GetProcess()->InsertWatchpoint(addr, size, Kernel::DebugWatchpointType::Read);
         break;
     case BreakpointType::AccessWatch:
-        success = system.ApplicationProcess()->InsertWatchpoint(
-            addr, size, Kernel::DebugWatchpointType::ReadOrWrite);
+        success =
+            GetProcess()->InsertWatchpoint(addr, size, Kernel::DebugWatchpointType::ReadOrWrite);
         break;
     case BreakpointType::Hardware:
     default:
@@ -400,7 +398,7 @@ void GDBStub::HandleBreakpointRemove(std::string_view command) {
     const size_t addr{static_cast<size_t>(strtoll(command.data() + addr_sep, nullptr, 16))};
     const size_t size{static_cast<size_t>(strtoll(command.data() + size_sep, nullptr, 16))};
 
-    if (!system.ApplicationMemory().IsValidVirtualAddressRange(addr, size)) {
+    if (!GetMemory().IsValidVirtualAddressRange(addr, size)) {
         SendReply(GDB_STUB_REPLY_ERR);
         return;
     }
@@ -411,24 +409,22 @@ void GDBStub::HandleBreakpointRemove(std::string_view command) {
     case BreakpointType::Software: {
         const auto orig_insn{replaced_instructions.find(addr)};
         if (orig_insn != replaced_instructions.end()) {
-            system.ApplicationMemory().Write32(addr, orig_insn->second);
-            Core::InvalidateInstructionCacheRange(system.ApplicationProcess(), addr, sizeof(u32));
+            GetMemory().Write32(addr, orig_insn->second);
+            Core::InvalidateInstructionCacheRange(GetProcess(), addr, sizeof(u32));
             replaced_instructions.erase(addr);
             success = true;
         }
         break;
     }
     case BreakpointType::WriteWatch:
-        success = system.ApplicationProcess()->RemoveWatchpoint(addr, size,
-                                                                Kernel::DebugWatchpointType::Write);
+        success = GetProcess()->RemoveWatchpoint(addr, size, Kernel::DebugWatchpointType::Write);
         break;
     case BreakpointType::ReadWatch:
-        success = system.ApplicationProcess()->RemoveWatchpoint(addr, size,
-                                                                Kernel::DebugWatchpointType::Read);
+        success = GetProcess()->RemoveWatchpoint(addr, size, Kernel::DebugWatchpointType::Read);
         break;
     case BreakpointType::AccessWatch:
-        success = system.ApplicationProcess()->RemoveWatchpoint(
-            addr, size, Kernel::DebugWatchpointType::ReadOrWrite);
+        success =
+            GetProcess()->RemoveWatchpoint(addr, size, Kernel::DebugWatchpointType::ReadOrWrite);
         break;
     case BreakpointType::Hardware:
     default:
@@ -466,10 +462,10 @@ void GDBStub::HandleQuery(std::string_view command) {
         const auto target_xml{arch->GetTargetXML()};
         SendReply(PaginateBuffer(target_xml, command.substr(30)));
     } else if (command.starts_with("Offsets")) {
-        const auto main_offset = Core::FindMainModuleEntrypoint(system.ApplicationProcess());
+        const auto main_offset = Core::FindMainModuleEntrypoint(GetProcess());
         SendReply(fmt::format("TextSeg={:x}", GetInteger(main_offset)));
     } else if (command.starts_with("Xfer:libraries:read::")) {
-        auto modules = Core::FindModules(system.ApplicationProcess());
+        auto modules = Core::FindModules(GetProcess());
 
         std::string buffer;
         buffer += R"(<?xml version="1.0"?>)";
@@ -483,7 +479,7 @@ void GDBStub::HandleQuery(std::string_view command) {
         SendReply(PaginateBuffer(buffer, command.substr(21)));
     } else if (command.starts_with("fThreadInfo")) {
         // beginning of list
-        const auto& threads = system.ApplicationProcess()->GetThreadList();
+        const auto& threads = GetProcess()->GetThreadList();
         std::vector<std::string> thread_ids;
         for (const auto& thread : threads) {
             thread_ids.push_back(fmt::format("{:x}", thread.GetThreadId()));
@@ -497,7 +493,7 @@ void GDBStub::HandleQuery(std::string_view command) {
         buffer += R"(<?xml version="1.0"?>)";
         buffer += "<threads>";
 
-        const auto& threads = system.ApplicationProcess()->GetThreadList();
+        const auto& threads = GetProcess()->GetThreadList();
         for (const auto& thread : threads) {
             auto thread_name{Core::GetThreadName(&thread)};
             if (!thread_name) {
@@ -613,7 +609,7 @@ void GDBStub::HandleRcmd(const std::vector<u8>& command) {
     std::string_view command_str{reinterpret_cast<const char*>(&command[0]), command.size()};
     std::string reply;
 
-    auto* process = system.ApplicationProcess();
+    auto* process = GetProcess();
     auto& page_table = process->GetPageTable();
 
     const char* commands = "Commands:\n"
@@ -714,7 +710,7 @@ void GDBStub::HandleRcmd(const std::vector<u8>& command) {
 }
 
 Kernel::KThread* GDBStub::GetThreadByID(u64 thread_id) {
-    auto& threads{system.ApplicationProcess()->GetThreadList()};
+    auto& threads{GetProcess()->GetThreadList()};
     for (auto& thread : threads) {
         if (thread.GetThreadId() == thread_id) {
             return std::addressof(thread);
@@ -783,4 +779,12 @@ void GDBStub::SendStatus(char status) {
     backend.WriteToClient(buf);
 }
 
+Kernel::KProcess* GDBStub::GetProcess() {
+    return debug_process;
+}
+
+Core::Memory::Memory& GDBStub::GetMemory() {
+    return GetProcess()->GetMemory();
+}
+
 } // namespace Core
diff --git a/src/core/debugger/gdbstub.h b/src/core/debugger/gdbstub.h
index 368197920..232dcf49f 100644
--- a/src/core/debugger/gdbstub.h
+++ b/src/core/debugger/gdbstub.h
@@ -12,13 +12,22 @@
 #include "core/debugger/debugger_interface.h"
 #include "core/debugger/gdbstub_arch.h"
 
+namespace Kernel {
+class KProcess;
+}
+
+namespace Core::Memory {
+class Memory;
+}
+
 namespace Core {
 
 class System;
 
 class GDBStub : public DebuggerFrontend {
 public:
-    explicit GDBStub(DebuggerBackend& backend, Core::System& system);
+    explicit GDBStub(DebuggerBackend& backend, Core::System& system,
+                     Kernel::KProcess* debug_process);
     ~GDBStub() override;
 
     void Connected() override;
@@ -42,8 +51,12 @@ private:
     void SendReply(std::string_view data);
     void SendStatus(char status);
 
+    Kernel::KProcess* GetProcess();
+    Core::Memory::Memory& GetMemory();
+
 private:
     Core::System& system;
+    Kernel::KProcess* debug_process;
     std::unique_ptr<GDBStubArch> arch;
     std::vector<char> current_command;
     std::map<VAddr, u32> replaced_instructions;
diff --git a/src/core/file_sys/savedata_factory.cpp b/src/core/file_sys/savedata_factory.cpp
index 12b3bd797..23196cd5f 100644
--- a/src/core/file_sys/savedata_factory.cpp
+++ b/src/core/file_sys/savedata_factory.cpp
@@ -97,8 +97,9 @@ std::string SaveDataAttribute::DebugInfo() const {
                        static_cast<u8>(rank), index);
 }
 
-SaveDataFactory::SaveDataFactory(Core::System& system_, VirtualDir save_directory_)
-    : dir{std::move(save_directory_)}, system{system_} {
+SaveDataFactory::SaveDataFactory(Core::System& system_, ProgramId program_id_,
+                                 VirtualDir save_directory_)
+    : system{system_}, program_id{program_id_}, dir{std::move(save_directory_)} {
     // Delete all temporary storages
     // On hardware, it is expected that temporary storage be empty at first use.
     dir->DeleteSubdirectoryRecursive("temp");
@@ -110,7 +111,7 @@ VirtualDir SaveDataFactory::Create(SaveDataSpaceId space, const SaveDataAttribut
     PrintSaveDataAttributeWarnings(meta);
 
     const auto save_directory =
-        GetFullPath(system, dir, space, meta.type, meta.title_id, meta.user_id, meta.save_id);
+        GetFullPath(program_id, dir, space, meta.type, meta.title_id, meta.user_id, meta.save_id);
 
     return dir->CreateDirectoryRelative(save_directory);
 }
@@ -118,7 +119,7 @@ VirtualDir SaveDataFactory::Create(SaveDataSpaceId space, const SaveDataAttribut
 VirtualDir SaveDataFactory::Open(SaveDataSpaceId space, const SaveDataAttribute& meta) const {
 
     const auto save_directory =
-        GetFullPath(system, dir, space, meta.type, meta.title_id, meta.user_id, meta.save_id);
+        GetFullPath(program_id, dir, space, meta.type, meta.title_id, meta.user_id, meta.save_id);
 
     auto out = dir->GetDirectoryRelative(save_directory);
 
@@ -147,14 +148,14 @@ std::string SaveDataFactory::GetSaveDataSpaceIdPath(SaveDataSpaceId space) {
     }
 }
 
-std::string SaveDataFactory::GetFullPath(Core::System& system, VirtualDir dir,
+std::string SaveDataFactory::GetFullPath(ProgramId program_id, VirtualDir dir,
                                          SaveDataSpaceId space, SaveDataType type, u64 title_id,
                                          u128 user_id, u64 save_id) {
     // According to switchbrew, if a save is of type SaveData and the title id field is 0, it should
     // be interpreted as the title id of the current process.
     if (type == SaveDataType::SaveData || type == SaveDataType::DeviceSaveData) {
         if (title_id == 0) {
-            title_id = system.GetApplicationProcessProgramID();
+            title_id = program_id;
         }
     }
 
@@ -201,7 +202,7 @@ std::string SaveDataFactory::GetUserGameSaveDataRoot(u128 user_id, bool future)
 SaveDataSize SaveDataFactory::ReadSaveDataSize(SaveDataType type, u64 title_id,
                                                u128 user_id) const {
     const auto path =
-        GetFullPath(system, dir, SaveDataSpaceId::NandUser, type, title_id, user_id, 0);
+        GetFullPath(program_id, dir, SaveDataSpaceId::NandUser, type, title_id, user_id, 0);
     const auto relative_dir = GetOrCreateDirectoryRelative(dir, path);
 
     const auto size_file = relative_dir->GetFile(GetSaveDataSizeFileName());
@@ -220,7 +221,7 @@ SaveDataSize SaveDataFactory::ReadSaveDataSize(SaveDataType type, u64 title_id,
 void SaveDataFactory::WriteSaveDataSize(SaveDataType type, u64 title_id, u128 user_id,
                                         SaveDataSize new_value) const {
     const auto path =
-        GetFullPath(system, dir, SaveDataSpaceId::NandUser, type, title_id, user_id, 0);
+        GetFullPath(program_id, dir, SaveDataSpaceId::NandUser, type, title_id, user_id, 0);
     const auto relative_dir = GetOrCreateDirectoryRelative(dir, path);
 
     const auto size_file = relative_dir->CreateFile(GetSaveDataSizeFileName());
diff --git a/src/core/file_sys/savedata_factory.h b/src/core/file_sys/savedata_factory.h
index fd4887e99..30d96928e 100644
--- a/src/core/file_sys/savedata_factory.h
+++ b/src/core/file_sys/savedata_factory.h
@@ -87,10 +87,13 @@ constexpr const char* GetSaveDataSizeFileName() {
     return ".yuzu_save_size";
 }
 
+using ProgramId = u64;
+
 /// File system interface to the SaveData archive
 class SaveDataFactory {
 public:
-    explicit SaveDataFactory(Core::System& system_, VirtualDir save_directory_);
+    explicit SaveDataFactory(Core::System& system_, ProgramId program_id_,
+                             VirtualDir save_directory_);
     ~SaveDataFactory();
 
     VirtualDir Create(SaveDataSpaceId space, const SaveDataAttribute& meta) const;
@@ -99,7 +102,7 @@ public:
     VirtualDir GetSaveDataSpaceDirectory(SaveDataSpaceId space) const;
 
     static std::string GetSaveDataSpaceIdPath(SaveDataSpaceId space);
-    static std::string GetFullPath(Core::System& system, VirtualDir dir, SaveDataSpaceId space,
+    static std::string GetFullPath(ProgramId program_id, VirtualDir dir, SaveDataSpaceId space,
                                    SaveDataType type, u64 title_id, u128 user_id, u64 save_id);
     static std::string GetUserGameSaveDataRoot(u128 user_id, bool future);
 
@@ -110,8 +113,9 @@ public:
     void SetAutoCreate(bool state);
 
 private:
-    VirtualDir dir;
     Core::System& system;
+    ProgramId program_id;
+    VirtualDir dir;
     bool auto_create{true};
 };
 
diff --git a/src/core/hle/kernel/k_memory_block_manager.cpp b/src/core/hle/kernel/k_memory_block_manager.cpp
index 58a1e7216..f08a6e448 100644
--- a/src/core/hle/kernel/k_memory_block_manager.cpp
+++ b/src/core/hle/kernel/k_memory_block_manager.cpp
@@ -28,14 +28,14 @@ Result KMemoryBlockManager::Initialize(KProcessAddress st, KProcessAddress nd,
 }
 
 void KMemoryBlockManager::Finalize(KMemoryBlockSlabManager* slab_manager,
-                                   HostUnmapCallback&& host_unmap_callback) {
+                                   BlockCallback&& block_callback) {
     // Erase every block until we have none left.
     auto it = m_memory_block_tree.begin();
     while (it != m_memory_block_tree.end()) {
         KMemoryBlock* block = std::addressof(*it);
         it = m_memory_block_tree.erase(it);
+        block_callback(block->GetAddress(), block->GetSize());
         slab_manager->Free(block);
-        host_unmap_callback(block->GetAddress(), block->GetSize());
     }
 
     ASSERT(m_memory_block_tree.empty());
diff --git a/src/core/hle/kernel/k_memory_block_manager.h b/src/core/hle/kernel/k_memory_block_manager.h
index cb7b6f430..377628504 100644
--- a/src/core/hle/kernel/k_memory_block_manager.h
+++ b/src/core/hle/kernel/k_memory_block_manager.h
@@ -85,11 +85,11 @@ public:
 public:
     KMemoryBlockManager();
 
-    using HostUnmapCallback = std::function<void(Common::ProcessAddress, u64)>;
+    using BlockCallback = std::function<void(Common::ProcessAddress, u64)>;
 
     Result Initialize(KProcessAddress st, KProcessAddress nd,
                       KMemoryBlockSlabManager* slab_manager);
-    void Finalize(KMemoryBlockSlabManager* slab_manager, HostUnmapCallback&& host_unmap_callback);
+    void Finalize(KMemoryBlockSlabManager* slab_manager, BlockCallback&& block_callback);
 
     iterator end() {
         return m_memory_block_tree.end();
diff --git a/src/core/hle/kernel/k_page_table_base.cpp b/src/core/hle/kernel/k_page_table_base.cpp
index 73fbda331..3f0a39d33 100644
--- a/src/core/hle/kernel/k_page_table_base.cpp
+++ b/src/core/hle/kernel/k_page_table_base.cpp
@@ -431,15 +431,43 @@ Result KPageTableBase::InitializeForProcess(Svc::CreateProcessFlag as_type, bool
                                                m_memory_block_slab_manager));
 }
 
+Result KPageTableBase::FinalizeProcess() {
+    // Only process tables should be finalized.
+    ASSERT(!this->IsKernel());
+
+    // NOTE: Here Nintendo calls an unknown OnFinalize function.
+    // this->OnFinalize();
+
+    // NOTE: Here Nintendo calls a second unknown OnFinalize function.
+    // this->OnFinalize2();
+
+    // NOTE: Here Nintendo does a page table walk to discover heap pages to free.
+    // We will use the block manager finalization below to free them.
+
+    R_SUCCEED();
+}
+
 void KPageTableBase::Finalize() {
-    auto HostUnmapCallback = [&](KProcessAddress addr, u64 size) {
-        if (Settings::IsFastmemEnabled()) {
+    this->FinalizeProcess();
+
+    auto BlockCallback = [&](KProcessAddress addr, u64 size) {
+        if (m_impl->fastmem_arena) {
             m_system.DeviceMemory().buffer.Unmap(GetInteger(addr), size, false);
         }
+
+        // Get physical pages.
+        KPageGroup pg(m_kernel, m_block_info_manager);
+        this->MakePageGroup(pg, addr, size / PageSize);
+
+        // Free the pages.
+        pg.CloseAndReset();
     };
 
     // Finalize memory blocks.
-    m_memory_block_manager.Finalize(m_memory_block_slab_manager, std::move(HostUnmapCallback));
+    {
+        KScopedLightLock lk(m_general_lock);
+        m_memory_block_manager.Finalize(m_memory_block_slab_manager, std::move(BlockCallback));
+    }
 
     // Free any unsafe mapped memory.
     if (m_mapped_unsafe_physical_memory) {
diff --git a/src/core/hle/kernel/k_page_table_base.h b/src/core/hle/kernel/k_page_table_base.h
index 077cafc96..748419f86 100644
--- a/src/core/hle/kernel/k_page_table_base.h
+++ b/src/core/hle/kernel/k_page_table_base.h
@@ -241,6 +241,7 @@ public:
                                 KResourceLimit* resource_limit, Core::Memory::Memory& memory,
                                 KProcessAddress aslr_space_start);
 
+    Result FinalizeProcess();
     void Finalize();
 
     bool IsKernel() const {
diff --git a/src/core/hle/kernel/k_process.cpp b/src/core/hle/kernel/k_process.cpp
index 068e71dff..53735a225 100644
--- a/src/core/hle/kernel/k_process.cpp
+++ b/src/core/hle/kernel/k_process.cpp
@@ -171,6 +171,12 @@ void KProcess::Finalize() {
         m_resource_limit->Close();
     }
 
+    // Clear expensive resources, as the destructor is not called for guest objects.
+    for (auto& interface : m_arm_interfaces) {
+        interface.reset();
+    }
+    m_exclusive_monitor.reset();
+
     // Perform inherited finalization.
     KSynchronizationObject::Finalize();
 }
@@ -1233,10 +1239,10 @@ void KProcess::LoadModule(CodeSet code_set, KProcessAddress base_addr) {
     ReprotectSegment(code_set.DataSegment(), Svc::MemoryPermission::ReadWrite);
 
 #ifdef HAS_NCE
-    if (this->IsApplication() && Settings::IsNceEnabled()) {
+    const auto& patch = code_set.PatchSegment();
+    if (this->IsApplication() && Settings::IsNceEnabled() && patch.size != 0) {
         auto& buffer = m_kernel.System().DeviceMemory().buffer;
         const auto& code = code_set.CodeSegment();
-        const auto& patch = code_set.PatchSegment();
         buffer.Protect(GetInteger(base_addr + code.addr), code.size,
                        Common::MemoryPermission::Read | Common::MemoryPermission::Execute);
         buffer.Protect(GetInteger(base_addr + patch.addr), patch.size,
diff --git a/src/core/hle/kernel/kernel.cpp b/src/core/hle/kernel/kernel.cpp
index 1030f0c12..f3683cdcc 100644
--- a/src/core/hle/kernel/kernel.cpp
+++ b/src/core/hle/kernel/kernel.cpp
@@ -112,7 +112,14 @@ struct KernelCore::Impl {
             old_process->Close();
         }
 
-        process_list.clear();
+        {
+            std::scoped_lock lk{process_list_lock};
+            for (auto* const process : process_list) {
+                process->Terminate();
+                process->Close();
+            }
+            process_list.clear();
+        }
 
         next_object_id = 0;
         next_kernel_process_id = KProcess::InitialProcessIdMin;
@@ -770,6 +777,7 @@ struct KernelCore::Impl {
     std::atomic<u64> next_thread_id{1};
 
     // Lists all processes that exist in the current session.
+    std::mutex process_list_lock;
     std::vector<KProcess*> process_list;
     std::atomic<KProcess*> application_process{};
     std::unique_ptr<Kernel::GlobalSchedulerContext> global_scheduler_context;
@@ -869,9 +877,19 @@ KResourceLimit* KernelCore::GetSystemResourceLimit() {
 }
 
 void KernelCore::AppendNewProcess(KProcess* process) {
+    process->Open();
+
+    std::scoped_lock lk{impl->process_list_lock};
     impl->process_list.push_back(process);
 }
 
+void KernelCore::RemoveProcess(KProcess* process) {
+    std::scoped_lock lk{impl->process_list_lock};
+    if (std::erase(impl->process_list, process)) {
+        process->Close();
+    }
+}
+
 void KernelCore::MakeApplicationProcess(KProcess* process) {
     impl->MakeApplicationProcess(process);
 }
@@ -884,8 +902,15 @@ const KProcess* KernelCore::ApplicationProcess() const {
     return impl->application_process;
 }
 
-const std::vector<KProcess*>& KernelCore::GetProcessList() const {
-    return impl->process_list;
+std::list<KScopedAutoObject<KProcess>> KernelCore::GetProcessList() {
+    std::list<KScopedAutoObject<KProcess>> processes;
+    std::scoped_lock lk{impl->process_list_lock};
+
+    for (auto* const process : impl->process_list) {
+        processes.emplace_back(process);
+    }
+
+    return processes;
 }
 
 Kernel::GlobalSchedulerContext& KernelCore::GlobalSchedulerContext() {
diff --git a/src/core/hle/kernel/kernel.h b/src/core/hle/kernel/kernel.h
index 5d4102145..8ea5bed1c 100644
--- a/src/core/hle/kernel/kernel.h
+++ b/src/core/hle/kernel/kernel.h
@@ -5,6 +5,7 @@
 
 #include <array>
 #include <functional>
+#include <list>
 #include <memory>
 #include <string>
 #include <unordered_map>
@@ -116,8 +117,9 @@ public:
     /// Retrieves a shared pointer to the system resource limit instance.
     KResourceLimit* GetSystemResourceLimit();
 
-    /// Adds the given shared pointer to an internal list of active processes.
+    /// Adds/removes the given pointer to an internal list of active processes.
     void AppendNewProcess(KProcess* process);
+    void RemoveProcess(KProcess* process);
 
     /// Makes the given process the new application process.
     void MakeApplicationProcess(KProcess* process);
@@ -129,7 +131,7 @@ public:
     const KProcess* ApplicationProcess() const;
 
     /// Retrieves the list of processes.
-    const std::vector<KProcess*>& GetProcessList() const;
+    std::list<KScopedAutoObject<KProcess>> GetProcessList();
 
     /// Gets the sole instance of the global scheduler
     Kernel::GlobalSchedulerContext& GlobalSchedulerContext();
diff --git a/src/core/hle/kernel/svc/svc_process.cpp b/src/core/hle/kernel/svc/svc_process.cpp
index caa8bee9a..5c3e8829f 100644
--- a/src/core/hle/kernel/svc/svc_process.cpp
+++ b/src/core/hle/kernel/svc/svc_process.cpp
@@ -74,13 +74,15 @@ Result GetProcessList(Core::System& system, s32* out_num_processes, u64 out_proc
     }
 
     auto& memory = GetCurrentMemory(kernel);
-    const auto& process_list = kernel.GetProcessList();
+    auto process_list = kernel.GetProcessList();
+    auto it = process_list.begin();
+
     const auto num_processes = process_list.size();
     const auto copy_amount =
         std::min(static_cast<std::size_t>(out_process_ids_size), num_processes);
 
-    for (std::size_t i = 0; i < copy_amount; ++i) {
-        memory.Write64(out_process_ids, process_list[i]->GetProcessId());
+    for (std::size_t i = 0; i < copy_amount && it != process_list.end(); ++i, ++it) {
+        memory.Write64(out_process_ids, (*it)->GetProcessId());
         out_process_ids += sizeof(u64);
     }
 
diff --git a/src/core/hle/service/acc/profile_manager.cpp b/src/core/hle/service/acc/profile_manager.cpp
index 5542d6cbc..683f44e27 100644
--- a/src/core/hle/service/acc/profile_manager.cpp
+++ b/src/core/hle/service/acc/profile_manager.cpp
@@ -61,9 +61,7 @@ ProfileManager::ProfileManager() {
     OpenUser(*GetUser(current));
 }
 
-ProfileManager::~ProfileManager() {
-    WriteUserSaveFile();
-}
+ProfileManager::~ProfileManager() = default;
 
 /// After a users creation it needs to be "registered" to the system. AddToProfiles handles the
 /// internal management of the users profiles
@@ -113,6 +111,8 @@ Result ProfileManager::CreateNewUser(UUID uuid, const ProfileUsername& username)
         return ERROR_USER_ALREADY_EXISTS;
     }
 
+    is_save_needed = true;
+
     return AddUser({
         .user_uuid = uuid,
         .username = username,
@@ -326,6 +326,9 @@ bool ProfileManager::RemoveUser(UUID uuid) {
     profiles[*index] = ProfileInfo{};
     std::stable_partition(profiles.begin(), profiles.end(),
                           [](const ProfileInfo& profile) { return profile.user_uuid.IsValid(); });
+
+    is_save_needed = true;
+
     return true;
 }
 
@@ -340,6 +343,8 @@ bool ProfileManager::SetProfileBase(UUID uuid, const ProfileBase& profile_new) {
     profile.username = profile_new.username;
     profile.creation_time = profile_new.timestamp;
 
+    is_save_needed = true;
+
     return true;
 }
 
@@ -348,6 +353,7 @@ bool ProfileManager::SetProfileBaseAndData(Common::UUID uuid, const ProfileBase&
     const auto index = GetUserIndex(uuid);
     if (index.has_value() && SetProfileBase(uuid, profile_new)) {
         profiles[*index].data = data_new;
+        is_save_needed = true;
         return true;
     }
 
@@ -391,6 +397,10 @@ void ProfileManager::ParseUserSaveFile() {
 }
 
 void ProfileManager::WriteUserSaveFile() {
+    if (!is_save_needed) {
+        return;
+    }
+
     ProfileDataRaw raw{};
 
     for (std::size_t i = 0; i < MAX_USERS; ++i) {
@@ -423,7 +433,10 @@ void ProfileManager::WriteUserSaveFile() {
     if (!save.IsOpen() || !save.SetSize(sizeof(ProfileDataRaw)) || !save.WriteObject(raw)) {
         LOG_WARNING(Service_ACC, "Failed to write save data to file... No changes to user data "
                                  "made in current session will be saved.");
+        return;
     }
+
+    is_save_needed = false;
 }
 
 }; // namespace Service::Account
diff --git a/src/core/hle/service/acc/profile_manager.h b/src/core/hle/service/acc/profile_manager.h
index 900e32200..e21863e64 100644
--- a/src/core/hle/service/acc/profile_manager.h
+++ b/src/core/hle/service/acc/profile_manager.h
@@ -103,6 +103,7 @@ private:
     std::optional<std::size_t> AddToProfiles(const ProfileInfo& profile);
     bool RemoveProfileAtIndex(std::size_t index);
 
+    bool is_save_needed{};
     std::array<ProfileInfo, MAX_USERS> profiles{};
     std::array<ProfileInfo, MAX_USERS> stored_opened_profiles{};
     std::size_t user_count{};
diff --git a/src/core/hle/service/am/am.cpp b/src/core/hle/service/am/am.cpp
index 9e05bdafa..a768bdc54 100644
--- a/src/core/hle/service/am/am.cpp
+++ b/src/core/hle/service/am/am.cpp
@@ -36,6 +36,7 @@
 #include "core/hle/service/caps/caps_su.h"
 #include "core/hle/service/caps/caps_types.h"
 #include "core/hle/service/filesystem/filesystem.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
 #include "core/hle/service/ipc_helpers.h"
 #include "core/hle/service/ns/ns.h"
 #include "core/hle/service/nvnflinger/fb_share_buffer_manager.h"
@@ -2178,7 +2179,7 @@ void IApplicationFunctions::EnsureSaveData(HLERequestContext& ctx) {
     attribute.type = FileSys::SaveDataType::SaveData;
 
     FileSys::VirtualDir save_data{};
-    const auto res = system.GetFileSystemController().CreateSaveData(
+    const auto res = system.GetFileSystemController().OpenSaveDataController()->CreateSaveData(
         &save_data, FileSys::SaveDataSpaceId::NandUser, attribute);
 
     IPC::ResponseBuilder rb{ctx, 4};
@@ -2353,7 +2354,7 @@ void IApplicationFunctions::ExtendSaveData(HLERequestContext& ctx) {
               "new_journal={:016X}",
               static_cast<u8>(type), user_id[1], user_id[0], new_normal_size, new_journal_size);
 
-    system.GetFileSystemController().WriteSaveDataSize(
+    system.GetFileSystemController().OpenSaveDataController()->WriteSaveDataSize(
         type, system.GetApplicationProcessProgramID(), user_id,
         {new_normal_size, new_journal_size});
 
@@ -2378,7 +2379,7 @@ void IApplicationFunctions::GetSaveDataSize(HLERequestContext& ctx) {
     LOG_DEBUG(Service_AM, "called with type={:02X}, user_id={:016X}{:016X}", type, user_id[1],
               user_id[0]);
 
-    const auto size = system.GetFileSystemController().ReadSaveDataSize(
+    const auto size = system.GetFileSystemController().OpenSaveDataController()->ReadSaveDataSize(
         type, system.GetApplicationProcessProgramID(), user_id);
 
     IPC::ResponseBuilder rb{ctx, 6};
diff --git a/src/core/hle/service/audio/audin_u.cpp b/src/core/hle/service/audio/audin_u.cpp
index 56fee4591..de2aa6906 100644
--- a/src/core/hle/service/audio/audin_u.cpp
+++ b/src/core/hle/service/audio/audin_u.cpp
@@ -18,11 +18,11 @@ using namespace AudioCore::AudioIn;
 class IAudioIn final : public ServiceFramework<IAudioIn> {
 public:
     explicit IAudioIn(Core::System& system_, Manager& manager, size_t session_id,
-                      const std::string& device_name, const AudioInParameter& in_params, u32 handle,
-                      u64 applet_resource_user_id)
+                      const std::string& device_name, const AudioInParameter& in_params,
+                      Kernel::KProcess* handle, u64 applet_resource_user_id)
         : ServiceFramework{system_, "IAudioIn"},
           service_context{system_, "IAudioIn"}, event{service_context.CreateEvent("AudioInEvent")},
-          impl{std::make_shared<In>(system_, manager, event, session_id)} {
+          process{handle}, impl{std::make_shared<In>(system_, manager, event, session_id)} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {0, &IAudioIn::GetAudioInState, "GetAudioInState"},
@@ -45,6 +45,8 @@ public:
 
         RegisterHandlers(functions);
 
+        process->Open();
+
         if (impl->GetSystem()
                 .Initialize(device_name, in_params, handle, applet_resource_user_id)
                 .IsError()) {
@@ -55,6 +57,7 @@ public:
     ~IAudioIn() override {
         impl->Free();
         service_context.CloseEvent(event);
+        process->Close();
     }
 
     [[nodiscard]] std::shared_ptr<In> GetImpl() {
@@ -196,6 +199,7 @@ private:
 
     KernelHelpers::ServiceContext service_context;
     Kernel::KEvent* event;
+    Kernel::KProcess* process;
     std::shared_ptr<AudioCore::AudioIn::In> impl;
     Common::ScratchBuffer<u64> released_buffer;
 };
@@ -267,6 +271,14 @@ void AudInU::OpenAudioIn(HLERequestContext& ctx) {
     auto device_name = Common::StringFromBuffer(device_name_data);
     auto handle{ctx.GetCopyHandle(0)};
 
+    auto process{ctx.GetObjectFromHandle<Kernel::KProcess>(handle)};
+    if (process.IsNull()) {
+        LOG_ERROR(Service_Audio, "Failed to get process handle");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultUnknown);
+        return;
+    }
+
     std::scoped_lock l{impl->mutex};
     auto link{impl->LinkToManager()};
     if (link.IsError()) {
@@ -287,8 +299,9 @@ void AudInU::OpenAudioIn(HLERequestContext& ctx) {
     LOG_DEBUG(Service_Audio, "Opening new AudioIn, sessionid={}, free sessions={}", new_session_id,
               impl->num_free_sessions);
 
-    auto audio_in = std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name,
-                                               in_params, handle, applet_resource_user_id);
+    auto audio_in =
+        std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name, in_params,
+                                   process.GetPointerUnsafe(), applet_resource_user_id);
     impl->sessions[new_session_id] = audio_in->GetImpl();
     impl->applet_resource_user_ids[new_session_id] = applet_resource_user_id;
 
@@ -318,6 +331,14 @@ void AudInU::OpenAudioInProtocolSpecified(HLERequestContext& ctx) {
     auto device_name = Common::StringFromBuffer(device_name_data);
     auto handle{ctx.GetCopyHandle(0)};
 
+    auto process{ctx.GetObjectFromHandle<Kernel::KProcess>(handle)};
+    if (process.IsNull()) {
+        LOG_ERROR(Service_Audio, "Failed to get process handle");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultUnknown);
+        return;
+    }
+
     std::scoped_lock l{impl->mutex};
     auto link{impl->LinkToManager()};
     if (link.IsError()) {
@@ -338,8 +359,9 @@ void AudInU::OpenAudioInProtocolSpecified(HLERequestContext& ctx) {
     LOG_DEBUG(Service_Audio, "Opening new AudioIn, sessionid={}, free sessions={}", new_session_id,
               impl->num_free_sessions);
 
-    auto audio_in = std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name,
-                                               in_params, handle, applet_resource_user_id);
+    auto audio_in =
+        std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name, in_params,
+                                   process.GetPointerUnsafe(), applet_resource_user_id);
     impl->sessions[new_session_id] = audio_in->GetImpl();
     impl->applet_resource_user_ids[new_session_id] = applet_resource_user_id;
 
diff --git a/src/core/hle/service/audio/audout_u.cpp b/src/core/hle/service/audio/audout_u.cpp
index ca683d72c..8cc7b69f4 100644
--- a/src/core/hle/service/audio/audout_u.cpp
+++ b/src/core/hle/service/audio/audout_u.cpp
@@ -26,9 +26,10 @@ class IAudioOut final : public ServiceFramework<IAudioOut> {
 public:
     explicit IAudioOut(Core::System& system_, AudioCore::AudioOut::Manager& manager,
                        size_t session_id, const std::string& device_name,
-                       const AudioOutParameter& in_params, u32 handle, u64 applet_resource_user_id)
+                       const AudioOutParameter& in_params, Kernel::KProcess* handle,
+                       u64 applet_resource_user_id)
         : ServiceFramework{system_, "IAudioOut"}, service_context{system_, "IAudioOut"},
-          event{service_context.CreateEvent("AudioOutEvent")},
+          event{service_context.CreateEvent("AudioOutEvent")}, process{handle},
           impl{std::make_shared<AudioCore::AudioOut::Out>(system_, manager, event, session_id)} {
 
         // clang-format off
@@ -50,11 +51,14 @@ public:
         };
         // clang-format on
         RegisterHandlers(functions);
+
+        process->Open();
     }
 
     ~IAudioOut() override {
         impl->Free();
         service_context.CloseEvent(event);
+        process->Close();
     }
 
     [[nodiscard]] std::shared_ptr<AudioCore::AudioOut::Out> GetImpl() {
@@ -206,6 +210,7 @@ private:
 
     KernelHelpers::ServiceContext service_context;
     Kernel::KEvent* event;
+    Kernel::KProcess* process;
     std::shared_ptr<AudioCore::AudioOut::Out> impl;
     Common::ScratchBuffer<u64> released_buffer;
 };
@@ -257,6 +262,14 @@ void AudOutU::OpenAudioOut(HLERequestContext& ctx) {
     auto device_name = Common::StringFromBuffer(device_name_data);
     auto handle{ctx.GetCopyHandle(0)};
 
+    auto process{ctx.GetObjectFromHandle<Kernel::KProcess>(handle)};
+    if (process.IsNull()) {
+        LOG_ERROR(Service_Audio, "Failed to get process handle");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultUnknown);
+        return;
+    }
+
     auto link{impl->LinkToManager()};
     if (link.IsError()) {
         LOG_ERROR(Service_Audio, "Failed to link Audio Out to Audio Manager");
@@ -276,10 +289,11 @@ void AudOutU::OpenAudioOut(HLERequestContext& ctx) {
     LOG_DEBUG(Service_Audio, "Opening new AudioOut, sessionid={}, free sessions={}", new_session_id,
               impl->num_free_sessions);
 
-    auto audio_out = std::make_shared<IAudioOut>(system, *impl, new_session_id, device_name,
-                                                 in_params, handle, applet_resource_user_id);
-    result = audio_out->GetImpl()->GetSystem().Initialize(device_name, in_params, handle,
-                                                          applet_resource_user_id);
+    auto audio_out =
+        std::make_shared<IAudioOut>(system, *impl, new_session_id, device_name, in_params,
+                                    process.GetPointerUnsafe(), applet_resource_user_id);
+    result = audio_out->GetImpl()->GetSystem().Initialize(
+        device_name, in_params, process.GetPointerUnsafe(), applet_resource_user_id);
     if (result.IsError()) {
         LOG_ERROR(Service_Audio, "Failed to initialize the AudioOut System!");
         IPC::ResponseBuilder rb{ctx, 2};
diff --git a/src/core/hle/service/filesystem/filesystem.cpp b/src/core/hle/service/filesystem/filesystem.cpp
index 780f8c74d..ca6d8d607 100644
--- a/src/core/hle/service/filesystem/filesystem.cpp
+++ b/src/core/hle/service/filesystem/filesystem.cpp
@@ -24,15 +24,13 @@
 #include "core/hle/service/filesystem/fsp_ldr.h"
 #include "core/hle/service/filesystem/fsp_pr.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
+#include "core/hle/service/filesystem/romfs_controller.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
 #include "core/hle/service/server_manager.h"
 #include "core/loader/loader.h"
 
 namespace Service::FileSystem {
 
-// A default size for normal/journal save data size if application control metadata cannot be found.
-// This should be large enough to satisfy even the most extreme requirements (~4.2GB)
-constexpr u64 SUFFICIENT_SAVE_DATA_SIZE = 0xF0000000;
-
 static FileSys::VirtualDir GetDirectoryRelativeWrapped(FileSys::VirtualDir base,
                                                        std::string_view dir_name_) {
     std::string dir_name(Common::FS::SanitizePath(dir_name_));
@@ -297,145 +295,65 @@ FileSystemController::FileSystemController(Core::System& system_) : system{syste
 
 FileSystemController::~FileSystemController() = default;
 
-Result FileSystemController::RegisterRomFS(std::unique_ptr<FileSys::RomFSFactory>&& factory) {
-    romfs_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered RomFS");
-    return ResultSuccess;
-}
-
-Result FileSystemController::RegisterSaveData(std::unique_ptr<FileSys::SaveDataFactory>&& factory) {
-    ASSERT_MSG(save_data_factory == nullptr, "Tried to register a second save data");
-    save_data_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered save data");
-    return ResultSuccess;
-}
+Result FileSystemController::RegisterProcess(
+    ProcessId process_id, ProgramId program_id,
+    std::shared_ptr<FileSys::RomFSFactory>&& romfs_factory) {
+    std::scoped_lock lk{registration_lock};
 
-Result FileSystemController::RegisterSDMC(std::unique_ptr<FileSys::SDMCFactory>&& factory) {
-    ASSERT_MSG(sdmc_factory == nullptr, "Tried to register a second SDMC");
-    sdmc_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered SDMC");
-    return ResultSuccess;
-}
+    registrations.emplace(process_id, Registration{
+                                          .program_id = program_id,
+                                          .romfs_factory = std::move(romfs_factory),
+                                          .save_data_factory = CreateSaveDataFactory(program_id),
+                                      });
 
-Result FileSystemController::RegisterBIS(std::unique_ptr<FileSys::BISFactory>&& factory) {
-    ASSERT_MSG(bis_factory == nullptr, "Tried to register a second BIS");
-    bis_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered BIS");
+    LOG_DEBUG(Service_FS, "Registered for process {}", process_id);
     return ResultSuccess;
 }
 
-void FileSystemController::SetPackedUpdate(FileSys::VirtualFile update_raw) {
-    LOG_TRACE(Service_FS, "Setting packed update for romfs");
-
-    if (romfs_factory == nullptr)
-        return;
-
-    romfs_factory->SetPackedUpdate(std::move(update_raw));
-}
-
-FileSys::VirtualFile FileSystemController::OpenRomFSCurrentProcess() const {
-    LOG_TRACE(Service_FS, "Opening RomFS for current process");
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->OpenCurrentProcess(system.GetApplicationProcessProgramID());
-}
-
-FileSys::VirtualFile FileSystemController::OpenPatchedRomFS(u64 title_id,
-                                                            FileSys::ContentRecordType type) const {
-    LOG_TRACE(Service_FS, "Opening patched RomFS for title_id={:016X}", title_id);
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->OpenPatchedRomFS(title_id, type);
-}
-
-FileSys::VirtualFile FileSystemController::OpenPatchedRomFSWithProgramIndex(
-    u64 title_id, u8 program_index, FileSys::ContentRecordType type) const {
-    LOG_TRACE(Service_FS, "Opening patched RomFS for title_id={:016X}, program_index={}", title_id,
-              program_index);
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->OpenPatchedRomFSWithProgramIndex(title_id, program_index, type);
-}
-
-FileSys::VirtualFile FileSystemController::OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
-                                                     FileSys::ContentRecordType type) const {
-    LOG_TRACE(Service_FS, "Opening RomFS for title_id={:016X}, storage_id={:02X}, type={:02X}",
-              title_id, storage_id, type);
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->Open(title_id, storage_id, type);
-}
-
-std::shared_ptr<FileSys::NCA> FileSystemController::OpenBaseNca(
-    u64 title_id, FileSys::StorageId storage_id, FileSys::ContentRecordType type) const {
-    return romfs_factory->GetEntry(title_id, storage_id, type);
-}
-
-Result FileSystemController::CreateSaveData(FileSys::VirtualDir* out_save_data,
-                                            FileSys::SaveDataSpaceId space,
-                                            const FileSys::SaveDataAttribute& save_struct) const {
-    LOG_TRACE(Service_FS, "Creating Save Data for space_id={:01X}, save_struct={}", space,
-              save_struct.DebugInfo());
+Result FileSystemController::OpenProcess(
+    ProgramId* out_program_id, std::shared_ptr<SaveDataController>* out_save_data_controller,
+    std::shared_ptr<RomFsController>* out_romfs_controller, ProcessId process_id) {
+    std::scoped_lock lk{registration_lock};
 
-    if (save_data_factory == nullptr) {
+    const auto it = registrations.find(process_id);
+    if (it == registrations.end()) {
         return FileSys::ERROR_ENTITY_NOT_FOUND;
     }
 
-    auto save_data = save_data_factory->Create(space, save_struct);
-    if (save_data == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
-
-    *out_save_data = save_data;
+    *out_program_id = it->second.program_id;
+    *out_save_data_controller =
+        std::make_shared<SaveDataController>(system, it->second.save_data_factory);
+    *out_romfs_controller =
+        std::make_shared<RomFsController>(it->second.romfs_factory, it->second.program_id);
     return ResultSuccess;
 }
 
-Result FileSystemController::OpenSaveData(FileSys::VirtualDir* out_save_data,
-                                          FileSys::SaveDataSpaceId space,
-                                          const FileSys::SaveDataAttribute& attribute) const {
-    LOG_TRACE(Service_FS, "Opening Save Data for space_id={:01X}, save_struct={}", space,
-              attribute.DebugInfo());
-
-    if (save_data_factory == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
+void FileSystemController::SetPackedUpdate(ProcessId process_id, FileSys::VirtualFile update_raw) {
+    LOG_TRACE(Service_FS, "Setting packed update for romfs");
 
-    auto save_data = save_data_factory->Open(space, attribute);
-    if (save_data == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    std::scoped_lock lk{registration_lock};
+    const auto it = registrations.find(process_id);
+    if (it == registrations.end()) {
+        return;
     }
 
-    *out_save_data = save_data;
-    return ResultSuccess;
+    it->second.romfs_factory->SetPackedUpdate(std::move(update_raw));
 }
 
-Result FileSystemController::OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
-                                               FileSys::SaveDataSpaceId space) const {
-    LOG_TRACE(Service_FS, "Opening Save Data Space for space_id={:01X}", space);
-
-    if (save_data_factory == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
+std::shared_ptr<SaveDataController> FileSystemController::OpenSaveDataController() {
+    return std::make_shared<SaveDataController>(system, CreateSaveDataFactory(ProgramId{}));
+}
 
-    auto save_data_space = save_data_factory->GetSaveDataSpaceDirectory(space);
-    if (save_data_space == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
+std::shared_ptr<FileSys::SaveDataFactory> FileSystemController::CreateSaveDataFactory(
+    ProgramId program_id) {
+    using YuzuPath = Common::FS::YuzuPath;
+    const auto rw_mode = FileSys::Mode::ReadWrite;
 
-    *out_save_data_space = save_data_space;
-    return ResultSuccess;
+    auto vfs = system.GetFilesystem();
+    const auto nand_directory =
+        vfs->OpenDirectory(Common::FS::GetYuzuPathString(YuzuPath::NANDDir), rw_mode);
+    return std::make_shared<FileSys::SaveDataFactory>(system, program_id,
+                                                      std::move(nand_directory));
 }
 
 Result FileSystemController::OpenSDMC(FileSys::VirtualDir* out_sdmc) const {
@@ -540,48 +458,6 @@ u64 FileSystemController::GetTotalSpaceSize(FileSys::StorageId id) const {
     return 0;
 }
 
-FileSys::SaveDataSize FileSystemController::ReadSaveDataSize(FileSys::SaveDataType type,
-                                                             u64 title_id, u128 user_id) const {
-    if (save_data_factory == nullptr) {
-        return {0, 0};
-    }
-
-    const auto value = save_data_factory->ReadSaveDataSize(type, title_id, user_id);
-
-    if (value.normal == 0 && value.journal == 0) {
-        FileSys::SaveDataSize new_size{SUFFICIENT_SAVE_DATA_SIZE, SUFFICIENT_SAVE_DATA_SIZE};
-
-        FileSys::NACP nacp;
-        const auto res = system.GetAppLoader().ReadControlData(nacp);
-
-        if (res != Loader::ResultStatus::Success) {
-            const FileSys::PatchManager pm{system.GetApplicationProcessProgramID(),
-                                           system.GetFileSystemController(),
-                                           system.GetContentProvider()};
-            const auto metadata = pm.GetControlMetadata();
-            const auto& nacp_unique = metadata.first;
-
-            if (nacp_unique != nullptr) {
-                new_size = {nacp_unique->GetDefaultNormalSaveSize(),
-                            nacp_unique->GetDefaultJournalSaveSize()};
-            }
-        } else {
-            new_size = {nacp.GetDefaultNormalSaveSize(), nacp.GetDefaultJournalSaveSize()};
-        }
-
-        WriteSaveDataSize(type, title_id, user_id, new_size);
-        return new_size;
-    }
-
-    return value;
-}
-
-void FileSystemController::WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
-                                             FileSys::SaveDataSize new_value) const {
-    if (save_data_factory != nullptr)
-        save_data_factory->WriteSaveDataSize(type, title_id, user_id, new_value);
-}
-
 void FileSystemController::SetGameCard(FileSys::VirtualFile file) {
     gamecard = std::make_unique<FileSys::XCI>(file);
     const auto dir = gamecard->ConcatenatedPseudoDirectory();
@@ -801,14 +677,9 @@ FileSys::VirtualDir FileSystemController::GetBCATDirectory(u64 title_id) const {
     return bis_factory->GetBCATDirectory(title_id);
 }
 
-void FileSystemController::SetAutoSaveDataCreation(bool enable) {
-    save_data_factory->SetAutoCreate(enable);
-}
-
 void FileSystemController::CreateFactories(FileSys::VfsFilesystem& vfs, bool overwrite) {
     if (overwrite) {
         bis_factory = nullptr;
-        save_data_factory = nullptr;
         sdmc_factory = nullptr;
     }
 
@@ -836,11 +707,6 @@ void FileSystemController::CreateFactories(FileSys::VfsFilesystem& vfs, bool ove
                                        bis_factory->GetUserNANDContents());
     }
 
-    if (save_data_factory == nullptr) {
-        save_data_factory =
-            std::make_unique<FileSys::SaveDataFactory>(system, std::move(nand_directory));
-    }
-
     if (sdmc_factory == nullptr) {
         sdmc_factory = std::make_unique<FileSys::SDMCFactory>(std::move(sd_directory),
                                                               std::move(sd_load_directory));
@@ -849,12 +715,19 @@ void FileSystemController::CreateFactories(FileSys::VfsFilesystem& vfs, bool ove
     }
 }
 
+void FileSystemController::Reset() {
+    std::scoped_lock lk{registration_lock};
+    registrations.clear();
+}
+
 void LoopProcess(Core::System& system) {
     auto server_manager = std::make_unique<ServerManager>(system);
 
+    const auto FileSystemProxyFactory = [&] { return std::make_shared<FSP_SRV>(system); };
+
     server_manager->RegisterNamedService("fsp-ldr", std::make_shared<FSP_LDR>(system));
     server_manager->RegisterNamedService("fsp:pr", std::make_shared<FSP_PR>(system));
-    server_manager->RegisterNamedService("fsp-srv", std::make_shared<FSP_SRV>(system));
+    server_manager->RegisterNamedService("fsp-srv", std::move(FileSystemProxyFactory));
     ServerManager::RunServer(std::move(server_manager));
 }
 
diff --git a/src/core/hle/service/filesystem/filesystem.h b/src/core/hle/service/filesystem/filesystem.h
index 276d264e1..48f37d289 100644
--- a/src/core/hle/service/filesystem/filesystem.h
+++ b/src/core/hle/service/filesystem/filesystem.h
@@ -43,6 +43,9 @@ class ServiceManager;
 
 namespace FileSystem {
 
+class RomFsController;
+class SaveDataController;
+
 enum class ContentStorageId : u32 {
     System,
     User,
@@ -61,32 +64,24 @@ enum class OpenDirectoryMode : u64 {
 };
 DECLARE_ENUM_FLAG_OPERATORS(OpenDirectoryMode);
 
+using ProcessId = u64;
+using ProgramId = u64;
+
 class FileSystemController {
 public:
     explicit FileSystemController(Core::System& system_);
     ~FileSystemController();
 
-    Result RegisterRomFS(std::unique_ptr<FileSys::RomFSFactory>&& factory);
-    Result RegisterSaveData(std::unique_ptr<FileSys::SaveDataFactory>&& factory);
-    Result RegisterSDMC(std::unique_ptr<FileSys::SDMCFactory>&& factory);
-    Result RegisterBIS(std::unique_ptr<FileSys::BISFactory>&& factory);
-
-    void SetPackedUpdate(FileSys::VirtualFile update_raw);
-    FileSys::VirtualFile OpenRomFSCurrentProcess() const;
-    FileSys::VirtualFile OpenPatchedRomFS(u64 title_id, FileSys::ContentRecordType type) const;
-    FileSys::VirtualFile OpenPatchedRomFSWithProgramIndex(u64 title_id, u8 program_index,
-                                                          FileSys::ContentRecordType type) const;
-    FileSys::VirtualFile OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
-                                   FileSys::ContentRecordType type) const;
-    std::shared_ptr<FileSys::NCA> OpenBaseNca(u64 title_id, FileSys::StorageId storage_id,
-                                              FileSys::ContentRecordType type) const;
-
-    Result CreateSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
-                          const FileSys::SaveDataAttribute& save_struct) const;
-    Result OpenSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
-                        const FileSys::SaveDataAttribute& save_struct) const;
-    Result OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
-                             FileSys::SaveDataSpaceId space) const;
+    Result RegisterProcess(ProcessId process_id, ProgramId program_id,
+                           std::shared_ptr<FileSys::RomFSFactory>&& factory);
+    Result OpenProcess(ProgramId* out_program_id,
+                       std::shared_ptr<SaveDataController>* out_save_data_controller,
+                       std::shared_ptr<RomFsController>* out_romfs_controller,
+                       ProcessId process_id);
+    void SetPackedUpdate(ProcessId process_id, FileSys::VirtualFile update_raw);
+
+    std::shared_ptr<SaveDataController> OpenSaveDataController();
+
     Result OpenSDMC(FileSys::VirtualDir* out_sdmc) const;
     Result OpenBISPartition(FileSys::VirtualDir* out_bis_partition,
                             FileSys::BisPartitionId id) const;
@@ -96,11 +91,6 @@ public:
     u64 GetFreeSpaceSize(FileSys::StorageId id) const;
     u64 GetTotalSpaceSize(FileSys::StorageId id) const;
 
-    FileSys::SaveDataSize ReadSaveDataSize(FileSys::SaveDataType type, u64 title_id,
-                                           u128 user_id) const;
-    void WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
-                           FileSys::SaveDataSize new_value) const;
-
     void SetGameCard(FileSys::VirtualFile file);
     FileSys::XCI* GetGameCard() const;
 
@@ -133,15 +123,24 @@ public:
 
     FileSys::VirtualDir GetBCATDirectory(u64 title_id) const;
 
-    void SetAutoSaveDataCreation(bool enable);
-
     // Creates the SaveData, SDMC, and BIS Factories. Should be called once and before any function
     // above is called.
     void CreateFactories(FileSys::VfsFilesystem& vfs, bool overwrite = true);
 
+    void Reset();
+
 private:
-    std::unique_ptr<FileSys::RomFSFactory> romfs_factory;
-    std::unique_ptr<FileSys::SaveDataFactory> save_data_factory;
+    std::shared_ptr<FileSys::SaveDataFactory> CreateSaveDataFactory(ProgramId program_id);
+
+    struct Registration {
+        ProgramId program_id;
+        std::shared_ptr<FileSys::RomFSFactory> romfs_factory;
+        std::shared_ptr<FileSys::SaveDataFactory> save_data_factory;
+    };
+
+    std::mutex registration_lock;
+    std::map<ProcessId, Registration> registrations;
+
     std::unique_ptr<FileSys::SDMCFactory> sdmc_factory;
     std::unique_ptr<FileSys::BISFactory> bis_factory;
 
diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index 82ecc1b90..a2397bec4 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -27,6 +27,8 @@
 #include "core/hle/result.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
+#include "core/hle/service/filesystem/romfs_controller.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
 #include "core/hle/service/hle_ipc.h"
 #include "core/hle/service/ipc_helpers.h"
 #include "core/reporter.h"
@@ -577,9 +579,11 @@ private:
 
 class ISaveDataInfoReader final : public ServiceFramework<ISaveDataInfoReader> {
 public:
-    explicit ISaveDataInfoReader(Core::System& system_, FileSys::SaveDataSpaceId space,
-                                 FileSystemController& fsc_)
-        : ServiceFramework{system_, "ISaveDataInfoReader"}, fsc{fsc_} {
+    explicit ISaveDataInfoReader(Core::System& system_,
+                                 std::shared_ptr<SaveDataController> save_data_controller_,
+                                 FileSys::SaveDataSpaceId space)
+        : ServiceFramework{system_, "ISaveDataInfoReader"}, save_data_controller{
+                                                                save_data_controller_} {
         static const FunctionInfo functions[] = {
             {0, &ISaveDataInfoReader::ReadSaveDataInfo, "ReadSaveDataInfo"},
         };
@@ -626,7 +630,7 @@ private:
 
     void FindAllSaves(FileSys::SaveDataSpaceId space) {
         FileSys::VirtualDir save_root{};
-        const auto result = fsc.OpenSaveDataSpace(&save_root, space);
+        const auto result = save_data_controller->OpenSaveDataSpace(&save_root, space);
 
         if (result != ResultSuccess || save_root == nullptr) {
             LOG_ERROR(Service_FS, "The save root for the space_id={:02X} was invalid!", space);
@@ -723,7 +727,8 @@ private:
     };
     static_assert(sizeof(SaveDataInfo) == 0x60, "SaveDataInfo has incorrect size.");
 
-    FileSystemController& fsc;
+    ProcessId process_id = 0;
+    std::shared_ptr<SaveDataController> save_data_controller;
     std::vector<SaveDataInfo> info;
     u64 next_entry_index = 0;
 };
@@ -863,21 +868,20 @@ FSP_SRV::FSP_SRV(Core::System& system_)
     if (Settings::values.enable_fs_access_log) {
         access_log_mode = AccessLogMode::SdCard;
     }
-
-    // This should be true on creation
-    fsc.SetAutoSaveDataCreation(true);
 }
 
 FSP_SRV::~FSP_SRV() = default;
 
 void FSP_SRV::SetCurrentProcess(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-    current_process_id = rp.Pop<u64>();
+    current_process_id = ctx.GetPID();
 
     LOG_DEBUG(Service_FS, "called. current_process_id=0x{:016X}", current_process_id);
 
+    const auto res =
+        fsc.OpenProcess(&program_id, &save_data_controller, &romfs_controller, current_process_id);
+
     IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    rb.Push(res);
 }
 
 void FSP_SRV::OpenFileSystemWithPatch(HLERequestContext& ctx) {
@@ -916,7 +920,8 @@ void FSP_SRV::CreateSaveDataFileSystem(HLERequestContext& ctx) {
               uid[1], uid[0]);
 
     FileSys::VirtualDir save_data_dir{};
-    fsc.CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandUser, save_struct);
+    save_data_controller->CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandUser,
+                                         save_struct);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
@@ -931,7 +936,8 @@ void FSP_SRV::CreateSaveDataFileSystemBySystemSaveDataId(HLERequestContext& ctx)
     LOG_DEBUG(Service_FS, "called save_struct = {}", save_struct.DebugInfo());
 
     FileSys::VirtualDir save_data_dir{};
-    fsc.CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandSystem, save_struct);
+    save_data_controller->CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandSystem,
+                                         save_struct);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
@@ -950,7 +956,8 @@ void FSP_SRV::OpenSaveDataFileSystem(HLERequestContext& ctx) {
     LOG_INFO(Service_FS, "called.");
 
     FileSys::VirtualDir dir{};
-    auto result = fsc.OpenSaveData(&dir, parameters.space_id, parameters.attribute);
+    auto result =
+        save_data_controller->OpenSaveData(&dir, parameters.space_id, parameters.attribute);
     if (result != ResultSuccess) {
         IPC::ResponseBuilder rb{ctx, 2, 0, 0};
         rb.Push(FileSys::ERROR_ENTITY_NOT_FOUND);
@@ -1001,7 +1008,7 @@ void FSP_SRV::OpenSaveDataInfoReaderBySaveDataSpaceId(HLERequestContext& ctx) {
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(ResultSuccess);
     rb.PushIpcInterface<ISaveDataInfoReader>(
-        std::make_shared<ISaveDataInfoReader>(system, space, fsc));
+        std::make_shared<ISaveDataInfoReader>(system, save_data_controller, space));
 }
 
 void FSP_SRV::OpenSaveDataInfoReaderOnlyCacheStorage(HLERequestContext& ctx) {
@@ -1009,8 +1016,8 @@ void FSP_SRV::OpenSaveDataInfoReaderOnlyCacheStorage(HLERequestContext& ctx) {
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(ResultSuccess);
-    rb.PushIpcInterface<ISaveDataInfoReader>(system, FileSys::SaveDataSpaceId::TemporaryStorage,
-                                             fsc);
+    rb.PushIpcInterface<ISaveDataInfoReader>(system, save_data_controller,
+                                             FileSys::SaveDataSpaceId::TemporaryStorage);
 }
 
 void FSP_SRV::WriteSaveDataFileSystemExtraDataBySaveDataAttribute(HLERequestContext& ctx) {
@@ -1050,7 +1057,7 @@ void FSP_SRV::OpenDataStorageByCurrentProcess(HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called");
 
     if (!romfs) {
-        auto current_romfs = fsc.OpenRomFSCurrentProcess();
+        auto current_romfs = romfs_controller->OpenRomFSCurrentProcess();
         if (!current_romfs) {
             // TODO (bunnei): Find the right error code to use here
             LOG_CRITICAL(Service_FS, "no file system interface available!");
@@ -1078,7 +1085,7 @@ void FSP_SRV::OpenDataStorageByDataId(HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called with storage_id={:02X}, unknown={:08X}, title_id={:016X}",
               storage_id, unknown, title_id);
 
-    auto data = fsc.OpenRomFS(title_id, storage_id, FileSys::ContentRecordType::Data);
+    auto data = romfs_controller->OpenRomFS(title_id, storage_id, FileSys::ContentRecordType::Data);
 
     if (!data) {
         const auto archive = FileSys::SystemArchive::SynthesizeSystemArchive(title_id);
@@ -1101,7 +1108,8 @@ void FSP_SRV::OpenDataStorageByDataId(HLERequestContext& ctx) {
 
     const FileSys::PatchManager pm{title_id, fsc, content_provider};
 
-    auto base = fsc.OpenBaseNca(title_id, storage_id, FileSys::ContentRecordType::Data);
+    auto base =
+        romfs_controller->OpenBaseNca(title_id, storage_id, FileSys::ContentRecordType::Data);
     auto storage = std::make_shared<IStorage>(
         system, pm.PatchRomFS(base.get(), std::move(data), FileSys::ContentRecordType::Data));
 
@@ -1129,9 +1137,8 @@ void FSP_SRV::OpenDataStorageWithProgramIndex(HLERequestContext& ctx) {
 
     LOG_DEBUG(Service_FS, "called, program_index={}", program_index);
 
-    auto patched_romfs =
-        fsc.OpenPatchedRomFSWithProgramIndex(system.GetApplicationProcessProgramID(), program_index,
-                                             FileSys::ContentRecordType::Program);
+    auto patched_romfs = romfs_controller->OpenPatchedRomFSWithProgramIndex(
+        program_id, program_index, FileSys::ContentRecordType::Program);
 
     if (!patched_romfs) {
         // TODO: Find the right error code to use here
@@ -1152,7 +1159,7 @@ void FSP_SRV::OpenDataStorageWithProgramIndex(HLERequestContext& ctx) {
 void FSP_SRV::DisableAutoSaveDataCreation(HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called");
 
-    fsc.SetAutoSaveDataCreation(false);
+    save_data_controller->SetAutoCreate(false);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
diff --git a/src/core/hle/service/filesystem/fsp_srv.h b/src/core/hle/service/filesystem/fsp_srv.h
index 280bc9867..26980af99 100644
--- a/src/core/hle/service/filesystem/fsp_srv.h
+++ b/src/core/hle/service/filesystem/fsp_srv.h
@@ -17,6 +17,9 @@ class FileSystemBackend;
 
 namespace Service::FileSystem {
 
+class RomFsController;
+class SaveDataController;
+
 enum class AccessLogVersion : u32 {
     V7_0_0 = 2,
 
@@ -67,6 +70,9 @@ private:
     u64 current_process_id = 0;
     u32 access_log_program_index = 0;
     AccessLogMode access_log_mode = AccessLogMode::None;
+    u64 program_id = 0;
+    std::shared_ptr<SaveDataController> save_data_controller;
+    std::shared_ptr<RomFsController> romfs_controller;
 };
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/romfs_controller.cpp b/src/core/hle/service/filesystem/romfs_controller.cpp
new file mode 100644
index 000000000..19c9cec72
--- /dev/null
+++ b/src/core/hle/service/filesystem/romfs_controller.cpp
@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/hle/service/filesystem/romfs_controller.h"
+
+namespace Service::FileSystem {
+
+RomFsController::RomFsController(std::shared_ptr<FileSys::RomFSFactory> factory_, u64 program_id_)
+    : factory{std::move(factory_)}, program_id{program_id_} {}
+RomFsController::~RomFsController() = default;
+
+FileSys::VirtualFile RomFsController::OpenRomFSCurrentProcess() {
+    return factory->OpenCurrentProcess(program_id);
+}
+
+FileSys::VirtualFile RomFsController::OpenPatchedRomFS(u64 title_id,
+                                                       FileSys::ContentRecordType type) {
+    return factory->OpenPatchedRomFS(title_id, type);
+}
+
+FileSys::VirtualFile RomFsController::OpenPatchedRomFSWithProgramIndex(
+    u64 title_id, u8 program_index, FileSys::ContentRecordType type) {
+    return factory->OpenPatchedRomFSWithProgramIndex(title_id, program_index, type);
+}
+
+FileSys::VirtualFile RomFsController::OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
+                                                FileSys::ContentRecordType type) {
+    return factory->Open(title_id, storage_id, type);
+}
+
+std::shared_ptr<FileSys::NCA> RomFsController::OpenBaseNca(u64 title_id,
+                                                           FileSys::StorageId storage_id,
+                                                           FileSys::ContentRecordType type) {
+    return factory->GetEntry(title_id, storage_id, type);
+}
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/romfs_controller.h b/src/core/hle/service/filesystem/romfs_controller.h
new file mode 100644
index 000000000..9a478f71d
--- /dev/null
+++ b/src/core/hle/service/filesystem/romfs_controller.h
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/file_sys/nca_metadata.h"
+#include "core/file_sys/romfs_factory.h"
+#include "core/file_sys/vfs_types.h"
+
+namespace Service::FileSystem {
+
+class RomFsController {
+public:
+    explicit RomFsController(std::shared_ptr<FileSys::RomFSFactory> factory_, u64 program_id_);
+    ~RomFsController();
+
+    FileSys::VirtualFile OpenRomFSCurrentProcess();
+    FileSys::VirtualFile OpenPatchedRomFS(u64 title_id, FileSys::ContentRecordType type);
+    FileSys::VirtualFile OpenPatchedRomFSWithProgramIndex(u64 title_id, u8 program_index,
+                                                          FileSys::ContentRecordType type);
+    FileSys::VirtualFile OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
+                                   FileSys::ContentRecordType type);
+    std::shared_ptr<FileSys::NCA> OpenBaseNca(u64 title_id, FileSys::StorageId storage_id,
+                                              FileSys::ContentRecordType type);
+
+private:
+    const std::shared_ptr<FileSys::RomFSFactory> factory;
+    const u64 program_id;
+};
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/save_data_controller.cpp b/src/core/hle/service/filesystem/save_data_controller.cpp
new file mode 100644
index 000000000..d19b3ea1e
--- /dev/null
+++ b/src/core/hle/service/filesystem/save_data_controller.cpp
@@ -0,0 +1,99 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/core.h"
+#include "core/file_sys/control_metadata.h"
+#include "core/file_sys/errors.h"
+#include "core/file_sys/patch_manager.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
+#include "core/loader/loader.h"
+
+namespace Service::FileSystem {
+
+namespace {
+
+// A default size for normal/journal save data size if application control metadata cannot be found.
+// This should be large enough to satisfy even the most extreme requirements (~4.2GB)
+constexpr u64 SufficientSaveDataSize = 0xF0000000;
+
+FileSys::SaveDataSize GetDefaultSaveDataSize(Core::System& system, u64 program_id) {
+    const FileSys::PatchManager pm{program_id, system.GetFileSystemController(),
+                                   system.GetContentProvider()};
+    const auto metadata = pm.GetControlMetadata();
+    const auto& nacp = metadata.first;
+
+    if (nacp != nullptr) {
+        return {nacp->GetDefaultNormalSaveSize(), nacp->GetDefaultJournalSaveSize()};
+    }
+
+    return {SufficientSaveDataSize, SufficientSaveDataSize};
+}
+
+} // namespace
+
+SaveDataController::SaveDataController(Core::System& system_,
+                                       std::shared_ptr<FileSys::SaveDataFactory> factory_)
+    : system{system_}, factory{std::move(factory_)} {}
+SaveDataController::~SaveDataController() = default;
+
+Result SaveDataController::CreateSaveData(FileSys::VirtualDir* out_save_data,
+                                          FileSys::SaveDataSpaceId space,
+                                          const FileSys::SaveDataAttribute& attribute) {
+    LOG_TRACE(Service_FS, "Creating Save Data for space_id={:01X}, save_struct={}", space,
+              attribute.DebugInfo());
+
+    auto save_data = factory->Create(space, attribute);
+    if (save_data == nullptr) {
+        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    }
+
+    *out_save_data = save_data;
+    return ResultSuccess;
+}
+
+Result SaveDataController::OpenSaveData(FileSys::VirtualDir* out_save_data,
+                                        FileSys::SaveDataSpaceId space,
+                                        const FileSys::SaveDataAttribute& attribute) {
+    auto save_data = factory->Open(space, attribute);
+    if (save_data == nullptr) {
+        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    }
+
+    *out_save_data = save_data;
+    return ResultSuccess;
+}
+
+Result SaveDataController::OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
+                                             FileSys::SaveDataSpaceId space) {
+    auto save_data_space = factory->GetSaveDataSpaceDirectory(space);
+    if (save_data_space == nullptr) {
+        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    }
+
+    *out_save_data_space = save_data_space;
+    return ResultSuccess;
+}
+
+FileSys::SaveDataSize SaveDataController::ReadSaveDataSize(FileSys::SaveDataType type, u64 title_id,
+                                                           u128 user_id) {
+    const auto value = factory->ReadSaveDataSize(type, title_id, user_id);
+
+    if (value.normal == 0 && value.journal == 0) {
+        const auto size = GetDefaultSaveDataSize(system, title_id);
+        factory->WriteSaveDataSize(type, title_id, user_id, size);
+        return size;
+    }
+
+    return value;
+}
+
+void SaveDataController::WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
+                                           FileSys::SaveDataSize new_value) {
+    factory->WriteSaveDataSize(type, title_id, user_id, new_value);
+}
+
+void SaveDataController::SetAutoCreate(bool state) {
+    factory->SetAutoCreate(state);
+}
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/save_data_controller.h b/src/core/hle/service/filesystem/save_data_controller.h
new file mode 100644
index 000000000..863188e4c
--- /dev/null
+++ b/src/core/hle/service/filesystem/save_data_controller.h
@@ -0,0 +1,35 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/file_sys/nca_metadata.h"
+#include "core/file_sys/savedata_factory.h"
+#include "core/file_sys/vfs_types.h"
+
+namespace Service::FileSystem {
+
+class SaveDataController {
+public:
+    explicit SaveDataController(Core::System& system,
+                                std::shared_ptr<FileSys::SaveDataFactory> factory_);
+    ~SaveDataController();
+
+    Result CreateSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
+                          const FileSys::SaveDataAttribute& attribute);
+    Result OpenSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
+                        const FileSys::SaveDataAttribute& attribute);
+    Result OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
+                             FileSys::SaveDataSpaceId space);
+
+    FileSys::SaveDataSize ReadSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id);
+    void WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
+                           FileSys::SaveDataSize new_value);
+    void SetAutoCreate(bool state);
+
+private:
+    Core::System& system;
+    const std::shared_ptr<FileSys::SaveDataFactory> factory;
+};
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/glue/arp.cpp b/src/core/hle/service/glue/arp.cpp
index 6f1151b03..1254b6d49 100644
--- a/src/core/hle/service/glue/arp.cpp
+++ b/src/core/hle/service/glue/arp.cpp
@@ -15,9 +15,10 @@
 namespace Service::Glue {
 
 namespace {
-std::optional<u64> GetTitleIDForProcessID(const Core::System& system, u64 process_id) {
-    const auto& list = system.Kernel().GetProcessList();
-    const auto iter = std::find_if(list.begin(), list.end(), [&process_id](const auto& process) {
+std::optional<u64> GetTitleIDForProcessID(Core::System& system, u64 process_id) {
+    auto list = system.Kernel().GetProcessList();
+
+    const auto iter = std::find_if(list.begin(), list.end(), [&process_id](auto& process) {
         return process->GetProcessId() == process_id;
     });
 
diff --git a/src/core/hle/service/hid/hid.cpp b/src/core/hle/service/hid/hid.cpp
index fc03a0a5f..4ce0a9834 100644
--- a/src/core/hle/service/hid/hid.cpp
+++ b/src/core/hle/service/hid/hid.cpp
@@ -22,12 +22,10 @@ void LoopProcess(Core::System& system) {
     std::shared_ptr<HidFirmwareSettings> firmware_settings =
         std::make_shared<HidFirmwareSettings>();
 
-    // TODO: Remove this hack until this service is emulated properly.
-    const auto process_list = system.Kernel().GetProcessList();
-    if (!process_list.empty()) {
-        resource_manager->Initialize();
-        resource_manager->RegisterAppletResourceUserId(process_list[0]->GetId(), true);
-    }
+    // TODO: Remove this hack when am is emulated properly.
+    resource_manager->Initialize();
+    resource_manager->RegisterAppletResourceUserId(system.ApplicationProcess()->GetProcessId(),
+                                                   true);
 
     server_manager->RegisterNamedService(
         "hid", std::make_shared<IHidServer>(system, resource_manager, firmware_settings));
diff --git a/src/core/hle/service/pm/pm.cpp b/src/core/hle/service/pm/pm.cpp
index d92499f05..b52468e41 100644
--- a/src/core/hle/service/pm/pm.cpp
+++ b/src/core/hle/service/pm/pm.cpp
@@ -22,27 +22,26 @@ constexpr Result ResultProcessNotFound{ErrorModule::PM, 1};
 
 constexpr u64 NO_PROCESS_FOUND_PID{0};
 
-std::optional<Kernel::KProcess*> SearchProcessList(
-    const std::vector<Kernel::KProcess*>& process_list,
-    std::function<bool(Kernel::KProcess*)> predicate) {
+using ProcessList = std::list<Kernel::KScopedAutoObject<Kernel::KProcess>>;
+
+template <typename F>
+Kernel::KScopedAutoObject<Kernel::KProcess> SearchProcessList(ProcessList& process_list,
+                                                              F&& predicate) {
     const auto iter = std::find_if(process_list.begin(), process_list.end(), predicate);
 
     if (iter == process_list.end()) {
-        return std::nullopt;
+        return nullptr;
     }
 
-    return *iter;
+    return iter->GetPointerUnsafe();
 }
 
-void GetApplicationPidGeneric(HLERequestContext& ctx,
-                              const std::vector<Kernel::KProcess*>& process_list) {
-    const auto process = SearchProcessList(process_list, [](const auto& proc) {
-        return proc->GetProcessId() == Kernel::KProcess::ProcessIdMin;
-    });
+void GetApplicationPidGeneric(HLERequestContext& ctx, ProcessList& process_list) {
+    auto process = SearchProcessList(process_list, [](auto& p) { return p->IsApplication(); });
 
     IPC::ResponseBuilder rb{ctx, 4};
     rb.Push(ResultSuccess);
-    rb.Push(process.has_value() ? (*process)->GetProcessId() : NO_PROCESS_FOUND_PID);
+    rb.Push(process.IsNull() ? NO_PROCESS_FOUND_PID : process->GetProcessId());
 }
 
 } // Anonymous namespace
@@ -80,8 +79,7 @@ private:
 
 class DebugMonitor final : public ServiceFramework<DebugMonitor> {
 public:
-    explicit DebugMonitor(Core::System& system_)
-        : ServiceFramework{system_, "pm:dmnt"}, kernel{system_.Kernel()} {
+    explicit DebugMonitor(Core::System& system_) : ServiceFramework{system_, "pm:dmnt"} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetJitDebugProcessIdList"},
@@ -106,12 +104,11 @@ private:
 
         LOG_DEBUG(Service_PM, "called, program_id={:016X}", program_id);
 
-        const auto process =
-            SearchProcessList(kernel.GetProcessList(), [program_id](const auto& proc) {
-                return proc->GetProgramId() == program_id;
-            });
+        auto list = kernel.GetProcessList();
+        auto process = SearchProcessList(
+            list, [program_id](auto& p) { return p->GetProgramId() == program_id; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -119,12 +116,13 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(ResultSuccess);
-        rb.Push((*process)->GetProcessId());
+        rb.Push(process->GetProcessId());
     }
 
     void GetApplicationProcessId(HLERequestContext& ctx) {
         LOG_DEBUG(Service_PM, "called");
-        GetApplicationPidGeneric(ctx, kernel.GetProcessList());
+        auto list = kernel.GetProcessList();
+        GetApplicationPidGeneric(ctx, list);
     }
 
     void AtmosphereGetProcessInfo(HLERequestContext& ctx) {
@@ -135,11 +133,10 @@ private:
 
         LOG_WARNING(Service_PM, "(Partial Implementation) called, pid={:016X}", pid);
 
-        const auto process = SearchProcessList(kernel.GetProcessList(), [pid](const auto& proc) {
-            return proc->GetProcessId() == pid;
-        });
+        auto list = kernel.GetProcessList();
+        auto process = SearchProcessList(list, [pid](auto& p) { return p->GetProcessId() == pid; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -159,7 +156,7 @@ private:
 
         OverrideStatus override_status{};
         ProgramLocation program_location{
-            .program_id = (*process)->GetProgramId(),
+            .program_id = process->GetProgramId(),
             .storage_id = 0,
         };
 
@@ -169,14 +166,11 @@ private:
         rb.PushRaw(program_location);
         rb.PushRaw(override_status);
     }
-
-    const Kernel::KernelCore& kernel;
 };
 
 class Info final : public ServiceFramework<Info> {
 public:
-    explicit Info(Core::System& system_, const std::vector<Kernel::KProcess*>& process_list_)
-        : ServiceFramework{system_, "pm:info"}, process_list{process_list_} {
+    explicit Info(Core::System& system_) : ServiceFramework{system_, "pm:info"} {
         static const FunctionInfo functions[] = {
             {0, &Info::GetProgramId, "GetProgramId"},
             {65000, &Info::AtmosphereGetProcessId, "AtmosphereGetProcessId"},
@@ -193,11 +187,11 @@ private:
 
         LOG_DEBUG(Service_PM, "called, process_id={:016X}", process_id);
 
-        const auto process = SearchProcessList(process_list, [process_id](const auto& proc) {
-            return proc->GetProcessId() == process_id;
-        });
+        auto list = kernel.GetProcessList();
+        auto process = SearchProcessList(
+            list, [process_id](auto& p) { return p->GetProcessId() == process_id; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -205,7 +199,7 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(ResultSuccess);
-        rb.Push((*process)->GetProgramId());
+        rb.Push(process->GetProgramId());
     }
 
     void AtmosphereGetProcessId(HLERequestContext& ctx) {
@@ -214,11 +208,11 @@ private:
 
         LOG_DEBUG(Service_PM, "called, program_id={:016X}", program_id);
 
-        const auto process = SearchProcessList(process_list, [program_id](const auto& proc) {
-            return proc->GetProgramId() == program_id;
-        });
+        auto list = system.Kernel().GetProcessList();
+        auto process = SearchProcessList(
+            list, [program_id](auto& p) { return p->GetProgramId() == program_id; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -226,16 +220,13 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(ResultSuccess);
-        rb.Push((*process)->GetProcessId());
+        rb.Push(process->GetProcessId());
     }
-
-    const std::vector<Kernel::KProcess*>& process_list;
 };
 
 class Shell final : public ServiceFramework<Shell> {
 public:
-    explicit Shell(Core::System& system_)
-        : ServiceFramework{system_, "pm:shell"}, kernel{system_.Kernel()} {
+    explicit Shell(Core::System& system_) : ServiceFramework{system_, "pm:shell"} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "LaunchProgram"},
@@ -257,10 +248,9 @@ public:
 private:
     void GetApplicationProcessIdForShell(HLERequestContext& ctx) {
         LOG_DEBUG(Service_PM, "called");
-        GetApplicationPidGeneric(ctx, kernel.GetProcessList());
+        auto list = kernel.GetProcessList();
+        GetApplicationPidGeneric(ctx, list);
     }
-
-    const Kernel::KernelCore& kernel;
 };
 
 void LoopProcess(Core::System& system) {
@@ -268,8 +258,7 @@ void LoopProcess(Core::System& system) {
 
     server_manager->RegisterNamedService("pm:bm", std::make_shared<BootMode>(system));
     server_manager->RegisterNamedService("pm:dmnt", std::make_shared<DebugMonitor>(system));
-    server_manager->RegisterNamedService(
-        "pm:info", std::make_shared<Info>(system, system.Kernel().GetProcessList()));
+    server_manager->RegisterNamedService("pm:info", std::make_shared<Info>(system));
     server_manager->RegisterNamedService("pm:shell", std::make_shared<Shell>(system));
     ServerManager::RunServer(std::move(server_manager));
 }
diff --git a/src/core/hle/service/server_manager.cpp b/src/core/hle/service/server_manager.cpp
index 15edb23e0..8ef49387d 100644
--- a/src/core/hle/service/server_manager.cpp
+++ b/src/core/hle/service/server_manager.cpp
@@ -256,8 +256,13 @@ Result ServerManager::WaitAndProcessImpl() {
 
         // Wait for a signal.
         s32 out_index{-1};
-        R_TRY(Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &out_index, wait_objs.data(),
-                                                   num_objs, -1));
+        R_TRY_CATCH(Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &out_index,
+                                                         wait_objs.data(), num_objs, -1)) {
+            R_CATCH(Kernel::ResultSessionClosed) {
+                // On session closed, index is updated and we don't want to return an error.
+            }
+        }
+        R_END_TRY_CATCH;
         ASSERT(out_index >= 0 && out_index < num_objs);
 
         // Set the output index.
diff --git a/src/core/loader/deconstructed_rom_directory.cpp b/src/core/loader/deconstructed_rom_directory.cpp
index c9f8707b7..9b75c660c 100644
--- a/src/core/loader/deconstructed_rom_directory.cpp
+++ b/src/core/loader/deconstructed_rom_directory.cpp
@@ -19,8 +19,54 @@
 #include "core/arm/nce/patcher.h"
 #endif
 
+#ifndef HAS_NCE
+namespace Core::NCE {
+class Patcher {};
+} // namespace Core::NCE
+#endif
+
 namespace Loader {
 
+struct PatchCollection {
+    explicit PatchCollection(bool is_application_) : is_application{is_application_} {
+        module_patcher_indices.fill(-1);
+        patchers.emplace_back();
+    }
+
+    std::vector<Core::NCE::Patcher>* GetPatchers() {
+        if (is_application && Settings::IsNceEnabled()) {
+            return &patchers;
+        }
+        return nullptr;
+    }
+
+    size_t GetTotalPatchSize() const {
+        size_t total_size{};
+#ifdef HAS_NCE
+        for (auto& patcher : patchers) {
+            total_size += patcher.GetSectionSize();
+        }
+#endif
+        return total_size;
+    }
+
+    void SaveIndex(size_t module) {
+        module_patcher_indices[module] = static_cast<s32>(patchers.size() - 1);
+    }
+
+    s32 GetIndex(size_t module) const {
+        return module_patcher_indices[module];
+    }
+
+    s32 GetLastIndex() const {
+        return static_cast<s32>(patchers.size()) - 1;
+    }
+
+    bool is_application;
+    std::vector<Core::NCE::Patcher> patchers;
+    std::array<s32, 13> module_patcher_indices{};
+};
+
 AppLoader_DeconstructedRomDirectory::AppLoader_DeconstructedRomDirectory(FileSys::VirtualFile file_,
                                                                          bool override_update_)
     : AppLoader(std::move(file_)), override_update(override_update_), is_hbl(false) {
@@ -142,18 +188,7 @@ AppLoader_DeconstructedRomDirectory::LoadResult AppLoader_DeconstructedRomDirect
     std::size_t code_size{};
 
     // Define an nce patch context for each potential module.
-#ifdef HAS_NCE
-    std::array<Core::NCE::Patcher, 13> module_patchers;
-#endif
-
-    const auto GetPatcher = [&](size_t i) -> Core::NCE::Patcher* {
-#ifdef HAS_NCE
-        if (is_application && Settings::IsNceEnabled()) {
-            return &module_patchers[i];
-        }
-#endif
-        return nullptr;
-    };
+    PatchCollection patch_ctx{is_application};
 
     // Use the NSO module loader to figure out the code layout
     for (size_t i = 0; i < static_modules.size(); i++) {
@@ -164,13 +199,14 @@ AppLoader_DeconstructedRomDirectory::LoadResult AppLoader_DeconstructedRomDirect
         }
 
         const bool should_pass_arguments = std::strcmp(module, "rtld") == 0;
-        const auto tentative_next_load_addr =
-            AppLoader_NSO::LoadModule(process, system, *module_file, code_size,
-                                      should_pass_arguments, false, {}, GetPatcher(i));
+        const auto tentative_next_load_addr = AppLoader_NSO::LoadModule(
+            process, system, *module_file, code_size, should_pass_arguments, false, {},
+            patch_ctx.GetPatchers(), patch_ctx.GetLastIndex());
         if (!tentative_next_load_addr) {
             return {ResultStatus::ErrorLoadingNSO, {}};
         }
 
+        patch_ctx.SaveIndex(i);
         code_size = *tentative_next_load_addr;
     }
 
@@ -184,6 +220,9 @@ AppLoader_DeconstructedRomDirectory::LoadResult AppLoader_DeconstructedRomDirect
         return 0;
     }();
 
+    // Add patch size to the total module size
+    code_size += patch_ctx.GetTotalPatchSize();
+
     // Setup the process code layout
     if (process.LoadFromMetadata(metadata, code_size, fastmem_base, is_hbl).IsError()) {
         return {ResultStatus::ErrorUnableToParseKernelMetadata, {}};
@@ -204,9 +243,9 @@ AppLoader_DeconstructedRomDirectory::LoadResult AppLoader_DeconstructedRomDirect
 
         const VAddr load_addr{next_load_addr};
         const bool should_pass_arguments = std::strcmp(module, "rtld") == 0;
-        const auto tentative_next_load_addr =
-            AppLoader_NSO::LoadModule(process, system, *module_file, load_addr,
-                                      should_pass_arguments, true, pm, GetPatcher(i));
+        const auto tentative_next_load_addr = AppLoader_NSO::LoadModule(
+            process, system, *module_file, load_addr, should_pass_arguments, true, pm,
+            patch_ctx.GetPatchers(), patch_ctx.GetIndex(i));
         if (!tentative_next_load_addr) {
             return {ResultStatus::ErrorLoadingNSO, {}};
         }
@@ -216,20 +255,6 @@ AppLoader_DeconstructedRomDirectory::LoadResult AppLoader_DeconstructedRomDirect
         LOG_DEBUG(Loader, "loaded module {} @ {:#X}", module, load_addr);
     }
 
-    // Find the RomFS by searching for a ".romfs" file in this directory
-    const auto& files = dir->GetFiles();
-    const auto romfs_iter =
-        std::find_if(files.begin(), files.end(), [](const FileSys::VirtualFile& f) {
-            return f->GetName().find(".romfs") != std::string::npos;
-        });
-
-    // Register the RomFS if a ".romfs" file was found
-    if (romfs_iter != files.end() && *romfs_iter != nullptr) {
-        romfs = *romfs_iter;
-        system.GetFileSystemController().RegisterRomFS(std::make_unique<FileSys::RomFSFactory>(
-            *this, system.GetContentProvider(), system.GetFileSystemController()));
-    }
-
     is_loaded = true;
     return {ResultStatus::Success,
             LoadParameters{metadata.GetMainThreadPriority(), metadata.GetMainThreadStackSize()}};
diff --git a/src/core/loader/nca.cpp b/src/core/loader/nca.cpp
index 814407535..2a32b1276 100644
--- a/src/core/loader/nca.cpp
+++ b/src/core/loader/nca.cpp
@@ -74,8 +74,10 @@ AppLoader_NCA::LoadResult AppLoader_NCA::Load(Kernel::KProcess& process, Core::S
         return load_result;
     }
 
-    system.GetFileSystemController().RegisterRomFS(std::make_unique<FileSys::RomFSFactory>(
-        *this, system.GetContentProvider(), system.GetFileSystemController()));
+    system.GetFileSystemController().RegisterProcess(
+        process.GetProcessId(), nca->GetTitleId(),
+        std::make_shared<FileSys::RomFSFactory>(*this, system.GetContentProvider(),
+                                                system.GetFileSystemController()));
 
     is_loaded = true;
     return load_result;
diff --git a/src/core/loader/nro.cpp b/src/core/loader/nro.cpp
index e74697cda..f8225d697 100644
--- a/src/core/loader/nro.cpp
+++ b/src/core/loader/nro.cpp
@@ -275,10 +275,12 @@ AppLoader_NRO::LoadResult AppLoader_NRO::Load(Kernel::KProcess& process, Core::S
         return {ResultStatus::ErrorLoadingNRO, {}};
     }
 
-    if (romfs != nullptr) {
-        system.GetFileSystemController().RegisterRomFS(std::make_unique<FileSys::RomFSFactory>(
-            *this, system.GetContentProvider(), system.GetFileSystemController()));
-    }
+    u64 program_id{};
+    ReadProgramId(program_id);
+    system.GetFileSystemController().RegisterProcess(
+        process.GetProcessId(), program_id,
+        std::make_unique<FileSys::RomFSFactory>(*this, system.GetContentProvider(),
+                                                system.GetFileSystemController()));
 
     is_loaded = true;
     return {ResultStatus::Success, LoadParameters{Kernel::KThread::DefaultThreadPriority,
diff --git a/src/core/loader/nso.cpp b/src/core/loader/nso.cpp
index b053a0d14..583b7e927 100644
--- a/src/core/loader/nso.cpp
+++ b/src/core/loader/nso.cpp
@@ -77,7 +77,8 @@ std::optional<VAddr> AppLoader_NSO::LoadModule(Kernel::KProcess& process, Core::
                                                const FileSys::VfsFile& nso_file, VAddr load_base,
                                                bool should_pass_arguments, bool load_into_process,
                                                std::optional<FileSys::PatchManager> pm,
-                                               Core::NCE::Patcher* patch) {
+                                               std::vector<Core::NCE::Patcher>* patches,
+                                               s32 patch_index) {
     if (nso_file.GetSize() < sizeof(NSOHeader)) {
         return std::nullopt;
     }
@@ -94,8 +95,11 @@ std::optional<VAddr> AppLoader_NSO::LoadModule(Kernel::KProcess& process, Core::
     // Allocate some space at the beginning if we are patching in PreText mode.
     const size_t module_start = [&]() -> size_t {
 #ifdef HAS_NCE
-        if (patch && patch->GetPatchMode() == Core::NCE::PatchMode::PreText) {
-            return patch->GetSectionSize();
+        if (patches && load_into_process) {
+            auto* patch = &patches->operator[](patch_index);
+            if (patch->GetPatchMode() == Core::NCE::PatchMode::PreText) {
+                return patch->GetSectionSize();
+            }
         }
 #endif
         return 0;
@@ -160,27 +164,24 @@ std::optional<VAddr> AppLoader_NSO::LoadModule(Kernel::KProcess& process, Core::
 #ifdef HAS_NCE
     // If we are computing the process code layout and using nce backend, patch.
     const auto& code = codeset.CodeSegment();
-    if (patch && patch->GetPatchMode() == Core::NCE::PatchMode::None) {
+    auto* patch = patches ? &patches->operator[](patch_index) : nullptr;
+    if (patch && !load_into_process) {
         // Patch SVCs and MRS calls in the guest code
-        patch->PatchText(program_image, code);
-
-        // Add patch section size to the module size.
-        image_size += static_cast<u32>(patch->GetSectionSize());
+        while (!patch->PatchText(program_image, code)) {
+            patch = &patches->emplace_back();
+        }
     } else if (patch) {
         // Relocate code patch and copy to the program_image.
-        patch->RelocateAndCopy(load_base, code, program_image, &process.GetPostHandlers());
-
-        // Update patch section.
-        auto& patch_segment = codeset.PatchSegment();
-        patch_segment.addr =
-            patch->GetPatchMode() == Core::NCE::PatchMode::PreText ? 0 : image_size;
-        patch_segment.size = static_cast<u32>(patch->GetSectionSize());
-
-        // Add patch section size to the module size. In PreText mode image_size
-        // already contains the patch segment as part of module_start.
-        if (patch->GetPatchMode() == Core::NCE::PatchMode::PostData) {
-            image_size += patch_segment.size;
+        if (patch->RelocateAndCopy(load_base, code, program_image, &process.GetPostHandlers())) {
+            // Update patch section.
+            auto& patch_segment = codeset.PatchSegment();
+            patch_segment.addr =
+                patch->GetPatchMode() == Core::NCE::PatchMode::PreText ? 0 : image_size;
+            patch_segment.size = static_cast<u32>(patch->GetSectionSize());
         }
+
+        // Refresh image_size to take account the patch section if it was added by RelocateAndCopy
+        image_size = static_cast<u32>(program_image.size());
     }
 #endif
 
diff --git a/src/core/loader/nso.h b/src/core/loader/nso.h
index 29b86ed4c..6356697e3 100644
--- a/src/core/loader/nso.h
+++ b/src/core/loader/nso.h
@@ -93,7 +93,8 @@ public:
                                            const FileSys::VfsFile& nso_file, VAddr load_base,
                                            bool should_pass_arguments, bool load_into_process,
                                            std::optional<FileSys::PatchManager> pm = {},
-                                           Core::NCE::Patcher* patch = nullptr);
+                                           std::vector<Core::NCE::Patcher>* patches = nullptr,
+                                           s32 patch_index = -1);
 
     LoadResult Load(Kernel::KProcess& process, Core::System& system) override;
 
diff --git a/src/core/loader/nsp.cpp b/src/core/loader/nsp.cpp
index f4ab75b77..28116ff3a 100644
--- a/src/core/loader/nsp.cpp
+++ b/src/core/loader/nsp.cpp
@@ -111,7 +111,8 @@ AppLoader_NSP::LoadResult AppLoader_NSP::Load(Kernel::KProcess& process, Core::S
 
     FileSys::VirtualFile update_raw;
     if (ReadUpdateRaw(update_raw) == ResultStatus::Success && update_raw != nullptr) {
-        system.GetFileSystemController().SetPackedUpdate(std::move(update_raw));
+        system.GetFileSystemController().SetPackedUpdate(process.GetProcessId(),
+                                                         std::move(update_raw));
     }
 
     is_loaded = true;
diff --git a/src/core/loader/xci.cpp b/src/core/loader/xci.cpp
index 12d72c380..e9abb199a 100644
--- a/src/core/loader/xci.cpp
+++ b/src/core/loader/xci.cpp
@@ -78,7 +78,8 @@ AppLoader_XCI::LoadResult AppLoader_XCI::Load(Kernel::KProcess& process, Core::S
 
     FileSys::VirtualFile update_raw;
     if (ReadUpdateRaw(update_raw) == ResultStatus::Success && update_raw != nullptr) {
-        system.GetFileSystemController().SetPackedUpdate(std::move(update_raw));
+        system.GetFileSystemController().SetPackedUpdate(process.GetProcessId(),
+                                                         std::move(update_raw));
     }
 
     is_loaded = true;