--- zzzz-none-000/linux-5.4.213/init/do_mounts.c	2022-09-15 10:04:56.000000000 +0000
+++ miami-7690-761/linux-5.4.213/init/do_mounts.c	2024-05-29 11:20:02.000000000 +0000
@@ -313,7 +313,9 @@
 }
 EXPORT_SYMBOL_GPL(name_to_dev_t);
 
-static int __init root_dev_setup(char *line)
+/* this isn't static anymore, as we need to have this function available for
+ * mtdram1= param parsing in our mtd code -PHU*/
+int __init root_dev_setup(char *line)
 {
 	strlcpy(saved_root_name, line, sizeof(saved_root_name));
 	return 1;
@@ -460,7 +462,30 @@
 out:
 	put_page(page);
 }
- 
+
+#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
+static int __init mount_ubi_rootfs(void)
+{
+	int flags = MS_SILENT;
+	int err, tried = 0;
+
+	while (tried < 2) {
+		err = do_mount_root("ubi0:rootfs", "ubifs", flags, \
+					root_mount_data);
+		switch (err) {
+			case -EACCES:
+				flags |= MS_RDONLY;
+				tried++;
+				break;
+			default:
+				return err;
+		}
+	}
+
+	return -EINVAL;
+}
+#endif
+
 #ifdef CONFIG_ROOT_NFS
 
 #define NFSROOT_TIMEOUT_MIN	5
@@ -554,6 +579,10 @@
 			change_floppy("root floppy");
 	}
 #endif
+#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
+	if (!mount_ubi_rootfs())
+		return;
+#endif
 #ifdef CONFIG_BLOCK
 	{
 		int err = create_dev("/dev/root", ROOT_DEV);
@@ -605,12 +634,31 @@
 		goto out;
 
 	/* wait for any asynchronous scanning to complete */
-	if ((ROOT_DEV == 0) && root_wait) {
+	if ((ROOT_DEV == 0) && root_wait && saved_root_name[0]) {
 		printk(KERN_INFO "Waiting for root device %s...\n",
 			saved_root_name);
 		while (driver_probe_done() != 0 ||
 			(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
 			msleep(5);
+
+		async_synchronize_full();
+	} else if (IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
+			(ROOT_DEV == 0) && root_wait) {
+		pr_info(KERN_INFO "Waiting for root device ...\n");
+		/*
+		 * Though MMC devices get detected before kernel
+		 * reaches here, GPT partition table parsing happens
+		 * later. Since we assume the GPT partition "rootfs",
+		 * as the device to mount the Root FS from, the
+		 * "root=xxx" command line option might not be
+		 * present resulting in 'saved_root_name' being NULL.
+		 * Hence, don't try to do 'name_to_dev_t' on it.
+		 * Eventually, ROOT_DEV will get updated by the GPT
+		 * parsing code and we will break out of this loop.
+		 */
+		while (driver_probe_done() != 0 || ROOT_DEV == 0)
+			msleep(100);
+
 		async_synchronize_full();
 	}