file_sys: Add functions to manage system archive importing

Provides a couple of functions that simply clearing and adding to imported sysdata.

src/core/CMakeLists.txt

@@ -86,6 +86,8 @@ add_library(core STATIC
     file_sys/system_archive/data/font_nintendo_extended.h
     file_sys/system_archive/data/font_standard.cpp
     file_sys/system_archive/data/font_standard.h
+    file_sys/system_archive/importer.cpp
+    file_sys/system_archive/importer.h
     file_sys/system_archive/mii_model.cpp
     file_sys/system_archive/mii_model.h
     file_sys/system_archive/ng_word.cpp

src/core/file_sys/system_archive/importer.cpp

@@ -0,0 +1,46 @@
+// Copyright 2019 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <fmt/format.h>
+#include "common/file_util.h"
+#include "core/file_sys/card_image.h"
+#include "core/file_sys/content_archive.h"
+#include "core/file_sys/system_archive/importer.h"
+#include "core/file_sys/vfs.h"
+#include "core/loader/loader.h"
+
+namespace FileSys::SystemArchive {
+
+VirtualFile GetImportedSystemArchive(const VirtualDir& sysdata, u64 title_id) {
+    const auto filename = fmt::format("{:016X}.arc", title_id);
+    return sysdata->GetFile(filename);
+}
+
+bool ImportSystemArchive(const VirtualDir& sysdata, u64 title_id, const VirtualFile& data) {
+    const auto filename = fmt::format("{:016X}.arc", title_id);
+    const auto out = sysdata->CreateFile(filename);
+    return out != nullptr && VfsRawCopy(data, out);
+}
+
+bool ImportDirectorySystemUpdate(const VirtualDir& sysdata, const VirtualDir& dir) {
+    Core::Crypto::KeyManager keys;
+
+    for (const auto& file : dir->GetFiles()) {
+        NCA nca{file, nullptr, 0, keys};
+        if (nca.GetStatus() == Loader::ResultStatus::Success &&
+            nca.GetType() == NCAContentType::Data && nca.GetRomFS() != nullptr) {
+            if (!ImportSystemArchive(sysdata, nca.GetTitleId(), nca.GetRomFS())) {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+bool ImportXCISystemUpdate(const VirtualDir& sysdata, XCI& xci) {
+    return ImportDirectorySystemUpdate(sysdata, xci.GetUpdatePartition());
+}
+
+} // namespace FileSys::SystemArchive

src/core/file_sys/system_archive/importer.h

@@ -0,0 +1,31 @@
+// Copyright 2019 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 {
+
+class NSP;
+class XCI;
+
+namespace SystemArchive {
+
+/// Returns the file corresponding to the title_id if it exists in sysdata.
+VirtualFile GetImportedSystemArchive(const VirtualDir& sysdata, u64 title_id);
+
+/// Copies the provided file into sysdata, overwriting current data.
+bool ImportSystemArchive(const VirtualDir& sysdata, u64 title_id, const VirtualFile& data);
+
+/// Copies all system archives in the directory to sysdata.
+bool ImportDirectorySystemUpdate(const VirtualDir& sysdata, const VirtualDir& dir);
+
+/// Calls ImportDirectorySystemUpdate on the update partition of the XCI.
+bool ImportXCISystemUpdate(const VirtualDir& sysdata, XCI& xci);
+
+} // namespace SystemArchive
+
+} // namespace FileSys