[][OpenWrt Dev][Enable configurable rootfs dev for UBI]
[Description]
Add support for UBI to use volumes other than "rootfs" for default rootfs
device for mounting root.
Configuration can be done by setting kernel commandline.
[Release-log]
N/A
Change-Id: Ie23517423970955e1d1b91a297c7cc3b70263663
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/6105792
diff --git a/target/linux/generic/pending-5.4/500-ubi-add-configurable-rootdev.patch b/target/linux/generic/pending-5.4/500-ubi-add-configurable-rootdev.patch
new file mode 100644
index 0000000..e0102c7
--- /dev/null
+++ b/target/linux/generic/pending-5.4/500-ubi-add-configurable-rootdev.patch
@@ -0,0 +1,35 @@
+--- a/drivers/mtd/ubi/block.c
++++ b/drivers/mtd/ubi/block.c
+@@ -97,6 +97,12 @@ static DEFINE_IDR(ubiblock_minor_idr);
+ static DEFINE_MUTEX(devices_mutex);
+ static int ubiblock_major;
+
++static char rootfs_volume[256] = "rootfs";
++module_param_string(rootfs_volume, rootfs_volume, sizeof(rootfs_volume), 0444);
++
++static bool no_default_rootdev;
++module_param(no_default_rootdev, bool, 0444);
++
+ static int __init ubiblock_set_param(const char *val,
+ const struct kernel_param *kp)
+ {
+@@ -460,8 +466,9 @@ int ubiblock_create(struct ubi_volume_in
+ dev->ubi_num, dev->vol_id, vi->name);
+ mutex_unlock(&devices_mutex);
+
+- if (!strcmp(vi->name, "rootfs") &&
++ if (!strcmp(vi->name, rootfs_volume) &&
+ IS_ENABLED(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
++ !no_default_rootdev &&
+ ROOT_DEV == 0) {
+ pr_notice("ubiblock: device ubiblock%d_%d (%s) set to be root filesystem\n",
+ dev->ubi_num, dev->vol_id, vi->name);
+@@ -681,7 +688,7 @@ static void __init ubiblock_create_auto_
+ struct ubi_volume_info vi;
+
+ for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++) {
+- desc = ubi_open_volume_nm(ubi_num, "rootfs", UBI_READONLY);
++ desc = ubi_open_volume_nm(ubi_num, rootfs_volume, UBI_READONLY);
+ if (IS_ERR(desc))
+ continue;
+