Force kernel to load rootfs only for legacy SAR devices

app/src/main/java/com/topjohnwu/magisk/core/Info.kt

@@ -28,6 +28,7 @@ object Info {
     // Device state
     @JvmStatic val env by lazy { loadState() }
     @JvmField var isSAR = false
+    var legacySAR = false
     var isAB = false
     @JvmField val isZygiskEnabled = System.getenv("ZYGISK_ENABLED") == "1"
     @JvmStatic val isFDE get() = crypto == "block"

app/src/main/java/com/topjohnwu/magisk/core/tasks/MagiskInstaller.kt

@@ -492,7 +492,7 @@ abstract class MagiskInstallImpl protected constructor(
             "KEEPVERITY=${Config.keepVerity} " +
             "PATCHVBMETAFLAG=${Config.patchVbmeta} " +
             "RECOVERYMODE=${Config.recovery} " +
-            "SYSTEM_ROOT=${Info.isSAR} " +
+            "LEGACYSAR=${Info.legacySAR} " +
             "sh boot_patch.sh $srcBoot")
         val isSuccess = cmds.sh().isSuccess
 

app/src/main/java/com/topjohnwu/magisk/core/utils/ShellInit.kt

@@ -78,6 +78,7 @@ class ShellInit : Shell.Initializer() {
         Info.vbmeta = getBool("VBMETAEXIST")
         Info.isAB = getBool("ISAB")
         Info.crypto = getVar("CRYPTOTYPE")
+        Info.legacySAR = getBool("LEGACYSAR")
 
         // Default presets
         Config.recovery = getBool("RECOVERYMODE")