From 73afc7d7f703bb6a4d001969627fb212d88f7d99 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Sat, 22 Oct 2022 19:33:34 -0700
Subject: [PATCH] 3DS: Allow loading ROM out of romfs if included

---
 src/platform/3ds/CMakeLists.txt |  2 +-
 src/platform/3ds/main.c         | 63 +++++++++++++++++++++++++++++++--
 2 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/src/platform/3ds/CMakeLists.txt b/src/platform/3ds/CMakeLists.txt
index 7fd3e270f..893af0317 100644
--- a/src/platform/3ds/CMakeLists.txt
+++ b/src/platform/3ds/CMakeLists.txt
@@ -1,4 +1,4 @@
-set(USE_VFS_3DS ON CACHE BOOL "Use 3DS-specific file support")
+set(USE_VFS_3DS OFF CACHE BOOL "Use 3DS-specific file support")
 mark_as_advanced(USE_VFS_3DS)
 
 find_program(3DSLINK 3dslink)
diff --git a/src/platform/3ds/main.c b/src/platform/3ds/main.c
index 71fcc1aa2..fad2fd96b 100644
--- a/src/platform/3ds/main.c
+++ b/src/platform/3ds/main.c
@@ -817,7 +817,43 @@ THREAD_ENTRY _core2Test(void* context) {
 	UNUSED(context);
 }
 
-int main() {
+bool setupRomfs(char* initialPath, size_t outLength, struct mGUIRunner* runner) {
+	int fd = open("romfs:/filename", O_RDONLY);
+	strcpy(initialPath, "romfs:/");
+	if (fd < 0) {
+		return false;
+	}
+	size_t len = strlen(initialPath);
+	ssize_t size = read(fd, initialPath + len, outLength - len);
+	if (size > 0 && initialPath[len + size - 1] == '\n') {
+		initialPath[len + size - 1] = '\0';
+	}
+	close(fd);
+	if (size <= 0) {
+		return false;
+	}
+	char basedir[64];
+	mCoreConfigDirectory(basedir, sizeof(basedir));
+	strlcat(basedir, "/forwarders", sizeof(basedir));
+	FSUSER_CreateDirectory(sdmcArchive, fsMakePath(PATH_ASCII, basedir), 0);
+
+	mCoreConfigSetValue(&runner->config, "savegamePath", basedir);
+	mCoreConfigSetValue(&runner->config, "savestatePath", basedir);
+	mCoreConfigSetValue(&runner->config, "screenshotPath", basedir);
+	mCoreConfigSetValue(&runner->config, "cheatsPath", basedir);
+	return true;
+}
+
+int main(int argc, char* argv[]) {
+	char initialPath[PATH_MAX] = { 0 };
+	if (argc > 1) {
+		strncpy(initialPath, argv[1], sizeof(PATH_MAX));
+	} else {
+		u8 hmac[0x20];
+		memset(hmac, 0, sizeof(hmac));
+		APT_ReceiveDeliverArg(initialPath, sizeof(initialPath), hmac, NULL, NULL);
+	}
+
 	rotation.d.sample = _sampleRotation;
 	rotation.d.readTiltX = _readTiltX;
 	rotation.d.readTiltY = _readTiltY;
@@ -1046,9 +1082,32 @@ int main() {
 	_map3DSKey(&runner.params.keyMap, KEY_CSTICK_UP, mGUI_INPUT_INCREASE_BRIGHTNESS);
 	_map3DSKey(&runner.params.keyMap, KEY_CSTICK_DOWN, mGUI_INPUT_DECREASE_BRIGHTNESS);
 
-	mGUIRunloop(&runner);
+	Result res = romfsInit();
+	bool useRomfs = false;
+	if (R_SUCCEEDED(res)) {
+		useRomfs = setupRomfs(initialPath, sizeof(initialPath), &runner);
+		if (!useRomfs) {
+			romfsExit();
+			_cleanup();
+			return 1;
+		}
+	}
+
+	if (initialPath[0] == '/' || useRomfs) {
+		size_t i;
+		for (i = 0; runner.keySources[i].id; ++i) {
+			mInputMapLoad(&runner.params.keyMap, runner.keySources[i].id, mCoreConfigGetInput(&runner.config));
+		}
+		mGUIRun(&runner, initialPath);
+	} else {
+		mGUIRunloop(&runner);
+	}
+
 	mGUIDeinit(&runner);
 
+	if (useRomfs) {
+		romfsExit();
+	}
 	_cleanup();
 	return 0;
 }