1 files changed, 60 insertions, 0 deletions
diff --git a/src/core/file_sys/nup_writer.h b/src/core/file_sys/nup_writer.h
new file mode 100644
index 0000000000..231387b156
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+++ b/src/core/file_sys/nup_writer.h
@@ -0,0 +1,60 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <atomic>
+#include <filesystem>
+#include <functional>
+#include <optional>
+#include <string>
+
+#include "common/common_types.h"
+
+// Packs a loose dump into a NUP container. Every package is kept: base/, each
+// updates/<version>/ and each dlc/<titleid>/<n>/.
+namespace FileSys::Nup {
+
+struct PackProgress {
+    u64 bytes_done{};
+    u64 bytes_total{};
+    u64 files_done{};
+    u64 files_total{};
+};
+
+enum class PackResult { Success, Cancelled, InvalidSource, IoError };
+
+// NupContainer keeps a zstd file in memory only while it fits its 512 MiB decompression cache;
+// a larger one is decompressed again in full on every read, which makes big compressed RomFS
+// files unusable. Files above this size are therefore stored raw, with headroom below the cap so
+// that one file does not evict everything else from the cache.
+constexpr u64 DefaultRawThreshold = 256ULL * 1024 * 1024;
+
+struct PackOptions {
+    // Low-storage mode: delete each source file once its extent is synced and journaled.
+    bool delete_sources = false;
+    u64 chunk_bytes = 256ULL * 1024 * 1024;
+    int zstd_level = 3;
+    // Files larger than this are always stored raw.
+    u64 raw_threshold = DefaultRawThreshold;
+};
+
+// A loose dump holds exefs/main and main.npdm, directly or under base/ or updates/<version>/,
+// and a romfs folder. Folder names are matched case-insensitively.
+bool IsLooseDump(const std::filesystem::path& dir);
+// The dump folder a game list entry's exefs/main (or exefs folder) belongs to, if it is a loose
+// dump.
+std::optional<std::filesystem::path> DumpRootFromMain(const std::filesystem::path& main);
+std::filesystem::path DefaultArchivePath(const std::filesystem::path& dump_root);
+
+// Writes <archive>.part and renames it when done; an existing archive is never overwritten. A
+// cancelled or failed low-storage run keeps its .part and .journal, and calling this again with
+// the same arguments resumes it.
+PackResult PackDump(const std::filesystem::path& dump_root, const std::filesystem::path& archive,
+                    const PackOptions& options = {},
+                    const std::function<void(const PackProgress&)>& progress = {},
+                    const std::atomic_bool* cancel = nullptr, std::string* error_out = nullptr);
+
+bool HasResumableJournal(const std::filesystem::path& archive);
+
+} // namespace FileSys::Nup