From ee0cef06a68f79d569919295f5bc5ca3b2755bd1 Mon Sep 17 00:00:00 2001
From: topjohnwu <topjohnwu@gmail.com>
Date: Sun, 22 Sep 2019 05:15:31 -0400
Subject: [PATCH] Add support for A-only 2SI

---
 native/jni/init/init.cpp    |  4 +++-
 native/jni/init/init.h      | 23 +++++++++++++++++------
 native/jni/init/rootdir.cpp | 10 +++++++++-
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/native/jni/init/init.cpp b/native/jni/init/init.cpp
index 99799213d..78fe5e407 100644
--- a/native/jni/init/init.cpp
+++ b/native/jni/init/init.cpp
@@ -207,7 +207,7 @@ int main(int argc, char *argv[]) {
 	if (run_test) {
 		init = make_unique<TestInit>(argv, &cmd);
 	} else if (cmd.force_normal_boot) {
-		init = make_unique<FirstStageInit>(argv, &cmd);
+		init = make_unique<ABFirstStageInit>(argv, &cmd);
 	} else if (cmd.system_as_root) {
 		if (access("/overlay", F_OK) == 0)  /* Compatible mode */
 			init = make_unique<SARCompatInit>(argv, &cmd);
@@ -217,6 +217,8 @@ int main(int argc, char *argv[]) {
 		decompress_ramdisk();
 		if (access("/sbin/recovery", F_OK) == 0)
 			init = make_unique<RecoveryInit>(argv, &cmd);
+		else if (access("/apex", F_OK) == 0)
+			init = make_unique<AFirstStageInit>(argv, &cmd);
 		else
 			init = make_unique<LegacyInit>(argv, &cmd);
 	}
diff --git a/native/jni/init/init.h b/native/jni/init/init.h
index b405fb544..e8267e298 100644
--- a/native/jni/init/init.h
+++ b/native/jni/init/init.h
@@ -97,21 +97,32 @@ public:
 	}
 };
 
-/* *******************
- * Logical Partitions
- * *******************/
+/* *************
+ * 2 Stage Init
+ * *************/
 
-class FirstStageInit : public BaseInit {
+class ABFirstStageInit : public BaseInit {
 protected:
 	void prepare();
 public:
-	FirstStageInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {};
+	ABFirstStageInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {};
 	void start() override {
 		prepare();
 		exec_init("/system/bin/init");
 	}
 };
 
+class AFirstStageInit : public BaseInit {
+protected:
+	void prepare();
+public:
+	AFirstStageInit(char *argv[], cmdline *cmd) : BaseInit(argv, cmd) {};
+	void start() override {
+		prepare();
+		exec_init();
+	}
+};
+
 class SecondStageInit : public SARCommon {
 protected:
 	void early_mount() override;
@@ -121,7 +132,7 @@ public:
 };
 
 /* ***********
- * Normal SAR
+ * Legacy SAR
  * ***********/
 
 class SARInit : public SARCommon {
diff --git a/native/jni/init/rootdir.cpp b/native/jni/init/rootdir.cpp
index 001bfe077..fde714db8 100644
--- a/native/jni/init/rootdir.cpp
+++ b/native/jni/init/rootdir.cpp
@@ -386,7 +386,7 @@ void SARCommon::patch_rootdir() {
 
 #define FSR "/first_stage_ramdisk"
 
-void FirstStageInit::prepare() {
+void ABFirstStageInit::prepare() {
 	// Find fstab
 	DIR *dir = xopendir(FSR);
 	if (!dir)
@@ -448,6 +448,14 @@ void FirstStageInit::prepare() {
 	rename("/overlay.d", FSR "/overlay.d");
 }
 
+void AFirstStageInit::prepare() {
+	// Move stuffs for next stage
+	xmkdir("/system", 0755);
+	xmkdir("/system/bin", 0755);
+	rename("/init", "/system/bin/init");
+	rename("/.backup/init", "/init");
+}
+
 #ifdef MAGISK_DEBUG
 static FILE *kmsg;
 static int vprintk(const char *fmt, va_list ap) {