8 files changed, 227 insertions, 1 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 73aec8ab0..882c9ab59 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -63,6 +63,10 @@ add_library(core STATIC
     file_sys/sdmc_factory.h
     file_sys/submission_package.cpp
     file_sys/submission_package.h
+    file_sys/system_archive/ng_word.cpp
+    file_sys/system_archive/ng_word.h
+    file_sys/system_archive/system_archive.cpp
+    file_sys/system_archive/system_archive.h
     file_sys/vfs.cpp
     file_sys/vfs.h
     file_sys/vfs_concat.cpp
diff --git a/src/core/file_sys/system_archive/ng_word.cpp b/src/core/file_sys/system_archive/ng_word.cpp
new file mode 100644
index 000000000..d0acdbd49
--- /dev/null
+++ b/src/core/file_sys/system_archive/ng_word.cpp
@@ -0,0 +1,42 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <fmt/format.h>
+#include "common/common_types.h"
+#include "core/file_sys/system_archive/ng_word.h"
+#include "core/file_sys/vfs_vector.h"
+
+namespace FileSys::SystemArchive {
+
+namespace NgWord1Data {
+
+constexpr std::size_t NUMBER_WORD_TXT_FILES = 0x10;
+
+// Should this archive replacement mysteriously not work on a future game, consider updating.
+constexpr std::array<u8, 4> VERSION_DAT{0x0, 0x0, 0x0, 0x19}; // 5.1.0 System Version
+
+constexpr std::array<u8, 30> WORD_TXT{
+    0xFE, 0xFF, 0x00, 0x5E, 0x00, 0x76, 0x00, 0x65, 0x00, 0x72, 0x00, 0x79, 0x00, 0x62, 0x00,
+    0x61, 0x00, 0x64, 0x00, 0x77, 0x00, 0x6F, 0x00, 0x72, 0x00, 0x64, 0x00, 0x24, 0x00, 0x0A,
+}; // "^verybadword$" in UTF-16
+
+} // namespace NgWord1Data
+
+VirtualDir NgWord1() {
+    std::vector<VirtualFile> files(NgWord1Data::NUMBER_WORD_TXT_FILES);
+
+    for (std::size_t i = 0; i < NgWord1Data::NUMBER_WORD_TXT_FILES; ++i) {
+        files[i] = std::make_shared<ArrayVfsFile<NgWord1Data::WORD_TXT.size()>>(
+            NgWord1Data::WORD_TXT, fmt::format("{}.txt", i));
+    }
+
+    files.push_back(std::make_shared<ArrayVfsFile<NgWord1Data::WORD_TXT.size()>>(
+        NgWord1Data::WORD_TXT, "common.txt"));
+    files.push_back(std::make_shared<ArrayVfsFile<NgWord1Data::VERSION_DAT.size()>>(
+        NgWord1Data::VERSION_DAT, "version.dat"));
+
+    return std::make_shared<VectorVfsDirectory>(files, std::vector<VirtualDir>{}, "data");
+}
+
+} // namespace FileSys::SystemArchive
diff --git a/src/core/file_sys/system_archive/ng_word.h b/src/core/file_sys/system_archive/ng_word.h
new file mode 100644
index 000000000..f4bc67344
--- /dev/null
+++ b/src/core/file_sys/system_archive/ng_word.h
@@ -0,0 +1,13 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/file_sys/vfs_types.h"
+
+namespace FileSys::SystemArchive {
+
+VirtualDir NgWord1();
+
+} // namespace FileSys::SystemArchive
diff --git a/src/core/file_sys/system_archive/system_archive.cpp b/src/core/file_sys/system_archive/system_archive.cpp
new file mode 100644
index 000000000..c9c40a07d
--- /dev/null
+++ b/src/core/file_sys/system_archive/system_archive.cpp
@@ -0,0 +1,91 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <functional>
+#include "common/logging/log.h"
+#include "core/file_sys/romfs.h"
+#include "core/file_sys/system_archive/ng_word.h"
+#include "core/file_sys/system_archive/system_archive.h"
+
+namespace FileSys::SystemArchive {
+
+constexpr u64 SYSTEM_ARCHIVE_BASE_TITLE_ID = 0x0100000000000800;
+constexpr std::size_t SYSTEM_ARCHIVE_COUNT = 0x28;
+
+using SystemArchiveSupplier = std::function<VirtualDir()>;
+
+struct SystemArchiveDescriptor {
+    u64 title_id;
+    const char* name;
+    SystemArchiveSupplier supplier;
+};
+
+const std::array<SystemArchiveDescriptor, SYSTEM_ARCHIVE_COUNT> SYSTEM_ARCHIVES = {{
+    {0x0100000000000800, "CertStore", nullptr},
+    {0x0100000000000801, "ErrorMessage", nullptr},
+    {0x0100000000000802, "MiiModel", nullptr},
+    {0x0100000000000803, "BrowserDll", nullptr},
+    {0x0100000000000804, "Help", nullptr},
+    {0x0100000000000805, "SharedFont", nullptr},
+    {0x0100000000000806, "NgWord", &NgWord1},
+    {0x0100000000000807, "SsidList", nullptr},
+    {0x0100000000000808, "Dictionary", nullptr},
+    {0x0100000000000809, "SystemVersion", nullptr},
+    {0x010000000000080A, "AvatarImage", nullptr},
+    {0x010000000000080B, "LocalNews", nullptr},
+    {0x010000000000080C, "Eula", nullptr},
+    {0x010000000000080D, "UrlBlackList", nullptr},
+    {0x010000000000080E, "TimeZoneBinary", nullptr},
+    {0x010000000000080F, "CertStoreCruiser", nullptr},
+    {0x0100000000000810, "FontNintendoExtension", nullptr},
+    {0x0100000000000811, "FontStandard", nullptr},
+    {0x0100000000000812, "FontKorean", nullptr},
+    {0x0100000000000813, "FontChineseTraditional", nullptr},
+    {0x0100000000000814, "FontChineseSimple", nullptr},
+    {0x0100000000000815, "FontBfcpx", nullptr},
+    {0x0100000000000816, "SystemUpdate", nullptr},
+    {0x0100000000000817, "0100000000000817", nullptr},
+    {0x0100000000000818, "FirmwareDebugSettings", nullptr},
+    {0x0100000000000819, "BootImagePackage", nullptr},
+    {0x010000000000081A, "BootImagePackageSafe", nullptr},
+    {0x010000000000081B, "BootImagePackageExFat", nullptr},
+    {0x010000000000081C, "BootImagePackageExFatSafe", nullptr},
+    {0x010000000000081D, "FatalMessage", nullptr},
+    {0x010000000000081E, "ControllerIcon", nullptr},
+    {0x010000000000081F, "PlatformConfigIcosa", nullptr},
+    {0x0100000000000820, "PlatformConfigCopper", nullptr},
+    {0x0100000000000821, "PlatformConfigHoag", nullptr},
+    {0x0100000000000822, "ControllerFirmware", nullptr},
+    {0x0100000000000823, "NgWord2", nullptr},
+    {0x0100000000000824, "PlatformConfigIcosaMariko", nullptr},
+    {0x0100000000000825, "ApplicationBlackList", nullptr},
+    {0x0100000000000826, "RebootlessSystemUpdateVersion", nullptr},
+    {0x0100000000000827, "ContentActionTable", nullptr},
+}};
+
+VirtualFile SynthesizeSystemArchive(const u64 title_id) {
+    if (title_id < SYSTEM_ARCHIVES.front().title_id || title_id > SYSTEM_ARCHIVES.back().title_id)
+        return nullptr;
+
+    const auto& desc = SYSTEM_ARCHIVES[title_id - SYSTEM_ARCHIVE_BASE_TITLE_ID];
+
+    LOG_INFO(Service_FS, "Synthesizing system archive '{}' (0x{:016X}).", desc.name, desc.title_id);
+
+    if (desc.supplier == nullptr)
+        return nullptr;
+
+    const auto dir = desc.supplier();
+
+    if (dir == nullptr)
+        return nullptr;
+
+    const auto romfs = CreateRomFS(dir);
+
+    if (romfs == nullptr)
+        return nullptr;
+
+    LOG_INFO(Service_FS, "    - System archive generation successful!");
+    return romfs;
+}
+} // namespace FileSys::SystemArchive
diff --git a/src/core/file_sys/system_archive/system_archive.h b/src/core/file_sys/system_archive/system_archive.h
new file mode 100644
index 000000000..724a8eb17
--- /dev/null
+++ b/src/core/file_sys/system_archive/system_archive.h
@@ -0,0 +1,14 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+#include "core/file_sys/vfs_types.h"
+
+namespace FileSys::SystemArchive {
+
+VirtualFile SynthesizeSystemArchive(u64 title_id);
+
+} // namespace FileSys::SystemArchive
diff --git a/src/core/file_sys/vfs_vector.cpp b/src/core/file_sys/vfs_vector.cpp
index 808f31e81..515626658 100644
--- a/src/core/file_sys/vfs_vector.cpp
+++ b/src/core/file_sys/vfs_vector.cpp
@@ -3,7 +3,6 @@
 // Refer to the license.txt file included.
 
 #include <algorithm>
-#include <cstring>
 #include <utility>
 #include "core/file_sys/vfs_vector.h"
 
diff --git a/src/core/file_sys/vfs_vector.h b/src/core/file_sys/vfs_vector.h
index 3e3f790c3..ac36cb2ee 100644
--- a/src/core/file_sys/vfs_vector.h
+++ b/src/core/file_sys/vfs_vector.h
@@ -4,10 +4,63 @@
 
 #pragma once
 
+#include <cstring>
 #include "core/file_sys/vfs.h"
 
 namespace FileSys {
 
+// An implementation of VfsFile that is backed by a statically-sized array
+template <std::size_t size>
+class ArrayVfsFile : public VfsFile {
+public:
+    ArrayVfsFile(std::array<u8, size> data, std::string name = "", VirtualDir parent = nullptr)
+        : data(data), name(std::move(name)), parent(std::move(parent)) {}
+
+    std::string GetName() const override {
+        return name;
+    }
+
+    std::size_t GetSize() const override {
+        return size;
+    }
+
+    bool Resize(std::size_t new_size) override {
+        return false;
+    }
+
+    std::shared_ptr<VfsDirectory> GetContainingDirectory() const override {
+        return parent;
+    }
+
+    bool IsWritable() const override {
+        return false;
+    }
+
+    bool IsReadable() const override {
+        return true;
+    }
+
+    std::size_t Read(u8* data_, std::size_t length, std::size_t offset) const override {
+        const auto read = std::min(length, size - offset);
+        std::memcpy(data_, data.data() + offset, read);
+        return read;
+    }
+
+    std::size_t Write(const u8* data, std::size_t length, std::size_t offset) override {
+        return 0;
+    }
+
+    bool Rename(std::string_view name) override {
+        this->name = name;
+        return true;
+    }
+
+private:
+    std::array<u8, size> data;
+    std::string name;
+    VirtualDir parent;
+};
+
 // An implementation of VfsFile that is backed by a vector optionally supplied upon construction
 class VectorVfsFile : public VfsFile {
 public:
diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index 694ec40ec..d2ffd5776 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -20,6 +20,7 @@
 #include "core/file_sys/nca_metadata.h"
 #include "core/file_sys/patch_manager.h"
 #include "core/file_sys/savedata_factory.h"
+#include "core/file_sys/system_archive/system_archive.h"
 #include "core/file_sys/vfs.h"
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/kernel/process.h"
@@ -831,6 +832,15 @@ void FSP_SRV::OpenDataStorageByDataId(Kernel::HLERequestContext& ctx) {
     auto data = OpenRomFS(title_id, storage_id, FileSys::ContentRecordType::Data);
 
     if (data.Failed()) {
+        const auto archive = FileSys::SystemArchive::SynthesizeSystemArchive(title_id);
+
+        if (archive != nullptr) {
+            IPC::ResponseBuilder rb{ctx, 2, 0, 1};
+            rb.Push(RESULT_SUCCESS);
+            rb.PushIpcInterface(std::make_shared<IStorage>(archive));
+            return;
+        }
+
         // TODO(DarkLordZach): Find the right error code to use here
         LOG_ERROR(Service_FS,
                   "could not open data storage with title_id={:016X}, storage_id={:02X}", title_id,