From b526c8ef0cb7a4f5946613b035ef0e54158541f6 Mon Sep 17 00:00:00 2001
From: Nathan Rajlich <n@n8.io>
Date: Mon, 24 Jun 2024 00:49:43 -0700
Subject: [PATCH] =?UTF-8?q?Add=20`Switch.version.emummc`=20to=20determine?=
 =?UTF-8?q?=20if=20Atmosph=C3=A8re=20is=20running=20from=20emuMMC=20or=20s?=
 =?UTF-8?q?ysMMC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .changeset/red-rocks-teach.md  |  5 +++++
 packages/runtime/src/switch.ts |  4 ++++
 source/main.c                  | 24 ++++++++++++++++++++++++
 3 files changed, 33 insertions(+)
 create mode 100644 .changeset/red-rocks-teach.md

diff --git a/.changeset/red-rocks-teach.md b/.changeset/red-rocks-teach.md
new file mode 100644
index 00000000..b60251dc
--- /dev/null
+++ b/.changeset/red-rocks-teach.md
@@ -0,0 +1,5 @@
+---
+"nxjs-runtime": patch
+---
+
+Add `Switch.version.emummc` to determine if Atmosphère is running from emuMMC or sysMMC
diff --git a/packages/runtime/src/switch.ts b/packages/runtime/src/switch.ts
index c563bd22..e79e8c15 100644
--- a/packages/runtime/src/switch.ts
+++ b/packages/runtime/src/switch.ts
@@ -31,6 +31,10 @@ export interface Versions {
 	 */
 	ams: string | undefined;
 	cairo: string;
+	/**
+	 * `true` if the Switch is running Atmosphère from emuMMC, `false` if running sysMMC, or `undefined` if not running Atmosphère.
+	 */
+	emummc: boolean | undefined;
 	freetype2: string;
 	harfbuzz: string;
 	hos: string;
diff --git a/source/main.c b/source/main.c
index 7fa7dcce..82abf585 100644
--- a/source/main.c
+++ b/source/main.c
@@ -452,6 +452,29 @@ static JSValue nx_version_get_ams(JSContext *ctx, JSValueConst this_val, int arg
 	return JS_NewString(ctx, version_str);
 }
 
+static JSValue nx_version_get_emummc(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
+{
+	if (!hosversionIsAtmosphere())
+	{
+		return JS_UNDEFINED;
+	}
+
+	nx_context_t *nx_ctx = JS_GetContextOpaque(ctx);
+	if (!nx_ctx->spl_initialized)
+	{
+		nx_ctx->spl_initialized = true;
+		splInitialize();
+	}
+
+	u64 is_emummc;
+	Result rc = splGetConfig((SplConfigItem)65007, &is_emummc);
+	if (R_FAILED(rc))
+	{
+		return nx_throw_libnx_error(ctx, rc, "splGetConfig(ExosphereEmummcType)");
+	}
+	return JS_NewBool(ctx, is_emummc ? true : false);
+}
+
 int nx_module_set_import_meta(JSContext *ctx, JSValueConst func_val,
 							  const char *url, JS_BOOL is_main)
 {
@@ -632,6 +655,7 @@ int main(int argc, char *argv[])
 	JSValue version_obj = JS_NewObject(ctx);
 	NX_DEF_GET_(version_obj, "ams", nx_version_get_ams, JS_PROP_C_W_E);
 	JS_SetPropertyStr(ctx, version_obj, "cairo", JS_NewString(ctx, cairo_version_string()));
+	NX_DEF_GET_(version_obj, "emummc", nx_version_get_emummc, JS_PROP_C_W_E);
 	JS_SetPropertyStr(ctx, version_obj, "freetype2", JS_NewString(ctx, FREETYPE_VERSION_STR));
 	JS_SetPropertyStr(ctx, version_obj, "harfbuzz", JS_NewString(ctx, HB_VERSION_STRING));
 	u32 hos_version = hosversionGet();