From 313620cad9646c963289fdfcf88527b9b59783f9 Mon Sep 17 00:00:00 2001
From: wheremyfoodat <44909372+wheremyfoodat@users.noreply.github.com>
Date: Tue, 23 Jan 2024 21:56:24 +0200
Subject: [PATCH] Implement SDMC Write-Only archive

---
 include/fs/archive_sdmc.hpp  |  6 ++++--
 include/services/fs.hpp      |  7 ++++---
 src/core/fs/archive_sdmc.cpp | 17 +++++++++++++++--
 src/core/services/fs.cpp     |  1 +
 4 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/include/fs/archive_sdmc.hpp b/include/fs/archive_sdmc.hpp
index 4aa80eabb..f63731c48 100644
--- a/include/fs/archive_sdmc.hpp
+++ b/include/fs/archive_sdmc.hpp
@@ -5,8 +5,10 @@
 using Result::HorizonResult;
 
 class SDMCArchive : public ArchiveBase {
-public:
-	SDMCArchive(Memory& mem) : ArchiveBase(mem) {}
+	bool isWriteOnly = false;  // There's 2 variants of the SDMC archive: Regular one (Read/Write) and write-only
+
+  public:
+	SDMCArchive(Memory& mem, bool writeOnly = false) : ArchiveBase(mem), isWriteOnly(writeOnly) {}
 
 	u64 getFreeBytes() override { return 1_GB; }
 	std::string name() override { return "SDMC"; }
diff --git a/include/services/fs.hpp b/include/services/fs.hpp
index 4d879e7f1..4a6131215 100644
--- a/include/services/fs.hpp
+++ b/include/services/fs.hpp
@@ -26,6 +26,7 @@ class FSService {
 	SelfNCCHArchive selfNcch;
 	SaveDataArchive saveData;
 	SDMCArchive sdmc;
+	SDMCArchive sdmcWriteOnly;
 	NCCHArchive ncch;
 
 	// UserSaveData archives
@@ -82,9 +83,9 @@ class FSService {
 
 public:
 	FSService(Memory& mem, Kernel& kernel, const EmulatorConfig& config)
-		: mem(mem), saveData(mem), sharedExtSaveData_nand(mem, "../SharedFiles/NAND", true), extSaveData_sdmc(mem, "SDMC"), sdmc(mem), selfNcch(mem),
-		  ncch(mem), userSaveData1(mem, ArchiveID::UserSaveData1), userSaveData2(mem, ArchiveID::UserSaveData2), kernel(kernel), config(config),
-		  systemSaveData(mem) {}
+		: mem(mem), saveData(mem), sharedExtSaveData_nand(mem, "../SharedFiles/NAND", true), extSaveData_sdmc(mem, "SDMC"), sdmc(mem),
+		  sdmcWriteOnly(mem, true), selfNcch(mem), ncch(mem), userSaveData1(mem, ArchiveID::UserSaveData1),
+		  userSaveData2(mem, ArchiveID::UserSaveData2), kernel(kernel), config(config), systemSaveData(mem) {}
 
 	void reset();
 	void handleSyncRequest(u32 messagePointer);
diff --git a/src/core/fs/archive_sdmc.cpp b/src/core/fs/archive_sdmc.cpp
index 232335d07..6c34de7ae 100644
--- a/src/core/fs/archive_sdmc.cpp
+++ b/src/core/fs/archive_sdmc.cpp
@@ -45,8 +45,16 @@ HorizonResult SDMCArchive::deleteFile(const FSPath& path) {
 
 FileDescriptor SDMCArchive::openFile(const FSPath& path, const FilePerms& perms) {
 	FilePerms realPerms = perms;
-	// SD card always has read permission
-	realPerms.raw |= (1 << 0);
+
+	if (isWriteOnly) {
+		if (perms.read()) {
+			Helpers::warn("SDMC: Read flag is not allowed in SDMC Write-Only archive");
+			return FileError;
+		}
+	} else {
+		// Regular SDMC archive always has read permission
+		realPerms.raw |= (1 << 0);
+	}
 
 	if ((realPerms.create() && !realPerms.write())) {
 		Helpers::panic("[SDMC] Unsupported flags for OpenFile");
@@ -130,6 +138,11 @@ HorizonResult SDMCArchive::createDirectory(const FSPath& path) {
 }
 
 Rust::Result<DirectorySession, HorizonResult> SDMCArchive::openDirectory(const FSPath& path) {
+	if (isWriteOnly) {
+		Helpers::warn("SDMC: OpenDirectory is not allowed in SDMC Write-Only archive");
+		return Err(Result::FS::UnexpectedFileOrDir);
+	}
+
 	if (path.type == PathType::UTF16) {
 		if (!isPathSafe<PathType::UTF16>(path)) {
 			Helpers::panic("Unsafe path in SaveData::OpenDirectory");
diff --git a/src/core/services/fs.cpp b/src/core/services/fs.cpp
index 264abcabb..2e1029586 100644
--- a/src/core/services/fs.cpp
+++ b/src/core/services/fs.cpp
@@ -97,6 +97,7 @@ ArchiveBase* FSService::getArchiveFromID(u32 id, const FSPath& archivePath) {
 
 		case ArchiveID::SystemSaveData: return &systemSaveData;
 		case ArchiveID::SDMC: return &sdmc;
+		case ArchiveID::SDMCWriteOnly: return &sdmcWriteOnly;
 		case ArchiveID::SavedataAndNcch: return &ncch; // This can only access NCCH outside of FSPXI
 		default:
 			Helpers::panic("Unknown archive. ID: %d\n", id);