kernel: ubifs: automount ubifs root only when CONFIG_UBIFS_ROOT is set

Kernel patches in generic/hack for 5.5, 6.1, and 6.6 that add
`CONFIG_UBIFS_ROOT` option to automount rootfs as ubifs rather than
using `CONFIG_MTD_ROOTFS_ROOT_DEV` which should only select the
appropriate MTD partition and not force any filesystem type or mounting.

Add `CONFIG_UBIFS_ROOT=y` to platforms where `FEATURES` included `ubifs`
and `MKUBIFS_OPTS` was set (at91, imx, layerscape)

Signed-off-by: Tony Butler <spudz76@gmail.com>

target/linux/at91/sam9x/config-6.6

@@ -310,6 +310,7 @@ CONFIG_TIMER_PROBE=y
 CONFIG_TINY_SRCU=y
 CONFIG_UBIFS_FS=y
 CONFIG_UBIFS_FS_ADVANCED_COMPR=y
+CONFIG_UBIFS_ROOT=y
 CONFIG_UNCOMPRESS_INCLUDE="debug/uncompress.h"
 CONFIG_UNWINDER_ARM=y
 CONFIG_USB=y

target/linux/at91/sama5/config-6.6

@@ -476,6 +476,7 @@ CONFIG_TINY_SRCU=y
 CONFIG_TOUCHSCREEN_ATMEL_MXT=y
 CONFIG_UACCESS_WITH_MEMCPY=y
 CONFIG_UBIFS_FS=y
+CONFIG_UBIFS_ROOT=y
 CONFIG_UNCOMPRESS_INCLUDE="debug/uncompress.h"
 CONFIG_UNWINDER_ARM=y
 CONFIG_USB=y

target/linux/at91/sama7/config-6.6

@@ -409,6 +409,7 @@ CONFIG_TICK_CPU_ACCOUNTING=y
 CONFIG_TIMER_OF=y
 CONFIG_TIMER_PROBE=y
 CONFIG_TINY_SRCU=y
+CONFIG_UBIFS_ROOT=y
 CONFIG_UACCESS_WITH_MEMCPY=y
 CONFIG_UNCOMPRESS_INCLUDE="debug/uncompress.h"
 CONFIG_UNWINDER_ARM=y

target/linux/generic/config-6.6

@@ -6717,6 +6717,7 @@ CONFIG_UBIFS_FS_LZO=y
 CONFIG_UBIFS_FS_XATTR=y
 CONFIG_UBIFS_FS_ZLIB=y
 CONFIG_UBIFS_FS_ZSTD=y
+# CONFIG_UBIFS_ROOT is not set
 # CONFIG_UBSAN is not set
 CONFIG_UBSAN_ALIGNMENT=y
 CONFIG_UBSAN_BOOL=y

target/linux/generic/hack-5.15/495-ubi-add-config-UBIFS_ROOT.patch

@@ -0,0 +1,50 @@
+From: Tony Butler <spudz76@gmail.com>
+Date: Mon, 22 Apr 2024 03:56:21 -0700
+Subject: kernel: ubifs: automount ubifs root only when CONFIG_UBIFS_ROOT is set
+
+Kernel patches in generic/hack for 5.5, 6.1, and 6.6 that add
+`CONFIG_UBIFS_ROOT` option to automount rootfs as ubifs rather than
+using `CONFIG_MTD_ROOTFS_ROOT_DEV` which should only select the
+appropriate MTD partition and not force any filesystem type or mounting.
+
+Signed-off-by: Tony Butler <spudz76@gmail.com>
+---
+ fs/ubifs/Kconfig            | 8 ++++++++
+ init/do_mounts.c            | 4 ++--
+ 2 files changed, 10 insertions(+), 2 deletions(-)
+
+--- a/fs/ubifs/Kconfig
++++ b/fs/ubifs/Kconfig
+@@ -98,4 +98,12 @@ config UBIFS_FS_AUTHENTICATION
+ 	  sha256, these are not selected automatically since there are many
+ 	  different options.
+ 
++config UBIFS_ROOT
++	bool "UBIFS root file system"
++	depends on UBIFS_FS=y
++	help
++	  Enables root file system support using UBIFS.
++
++	  Most people say N here.
++
+ endif # UBIFS_FS
+--- a/init/do_mounts.c
++++ b/init/do_mounts.c
+@@ -448,7 +448,7 @@ out:
+ 	put_page(page);
+ }
+ 
+-#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++#ifdef CONFIG_UBIFS_ROOT
+ static int __init mount_ubi_rootfs(void)
+ {
+ 	int flags = MS_SILENT;
+@@ -603,7 +603,7 @@ void __init mount_root(void)
+ 		return;
+ 	}
+ #endif
+-#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++#ifdef CONFIG_UBIFS_ROOT
+ 	if (!mount_ubi_rootfs())
+ 		return;
+ #endif

target/linux/generic/hack-6.1/495-ubi-add-config-UBIFS_ROOT.patch

@@ -0,0 +1,50 @@
+From: Tony Butler <spudz76@gmail.com>
+Date: Mon, 22 Apr 2024 03:56:21 -0700
+Subject: kernel: ubifs: automount ubifs root only when CONFIG_UBIFS_ROOT is set
+
+Kernel patches in generic/hack for 5.5, 6.1, and 6.6 that add
+`CONFIG_UBIFS_ROOT` option to automount rootfs as ubifs rather than
+using `CONFIG_MTD_ROOTFS_ROOT_DEV` which should only select the
+appropriate MTD partition and not force any filesystem type or mounting.
+
+Signed-off-by: Tony Butler <spudz76@gmail.com>
+---
+ fs/ubifs/Kconfig            | 8 ++++++++
+ init/do_mounts.c            | 4 ++--
+ 2 files changed, 10 insertions(+), 2 deletions(-)
+
+--- a/fs/ubifs/Kconfig
++++ b/fs/ubifs/Kconfig
+@@ -98,4 +98,12 @@ config UBIFS_FS_AUTHENTICATION
+ 	  sha256, these are not selected automatically since there are many
+ 	  different options.
+ 
++config UBIFS_ROOT
++	bool "UBIFS root file system"
++	depends on UBIFS_FS=y
++	help
++	  Enables root file system support using UBIFS.
++
++	  Most people say N here.
++
+ endif # UBIFS_FS
+--- a/init/do_mounts.c
++++ b/init/do_mounts.c
+@@ -447,7 +447,7 @@ out:
+ 	put_page(page);
+ }
+ 
+-#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++#ifdef CONFIG_UBIFS_ROOT
+ static int __init mount_ubi_rootfs(void)
+ {
+ 	int flags = MS_SILENT;
+@@ -602,7 +602,7 @@ void __init mount_root(void)
+ 		return;
+ 	}
+ #endif
+-#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++#ifdef CONFIG_UBIFS_ROOT
+ 	if (!mount_ubi_rootfs())
+ 		return;
+ #endif

target/linux/generic/hack-6.6/495-ubi-add-config-UBIFS_ROOT.patch

@@ -0,0 +1,50 @@
+From: Tony Butler <spudz76@gmail.com>
+Date: Mon, 22 Apr 2024 03:56:21 -0700
+Subject: kernel: ubifs: automount ubifs root only when CONFIG_UBIFS_ROOT is set
+
+Kernel patches in generic/hack for 5.5, 6.1, and 6.6 that add
+`CONFIG_UBIFS_ROOT` option to automount rootfs as ubifs rather than
+using `CONFIG_MTD_ROOTFS_ROOT_DEV` which should only select the
+appropriate MTD partition and not force any filesystem type or mounting.
+
+Signed-off-by: Tony Butler <spudz76@gmail.com>
+---
+ fs/ubifs/Kconfig            | 8 ++++++++
+ init/do_mounts.c            | 4 ++--
+ 2 files changed, 10 insertions(+), 2 deletions(-)
+
+--- a/fs/ubifs/Kconfig
++++ b/fs/ubifs/Kconfig
+@@ -98,4 +98,12 @@ config UBIFS_FS_AUTHENTICATION
+ 	  sha256, these are not selected automatically since there are many
+ 	  different options.
+ 
++config UBIFS_ROOT
++	bool "UBIFS root file system"
++	depends on UBIFS_FS=y
++	help
++	  Enables root file system support using UBIFS.
++
++	  Most people say N here.
++
+ endif # UBIFS_FS
+--- a/init/do_mounts.c
++++ b/init/do_mounts.c
+@@ -249,7 +249,7 @@ out:
+ 	put_page(page);
+ }
+ 
+-#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++#ifdef CONFIG_UBIFS_ROOT
+ static int __init mount_ubi_rootfs(void)
+ {
+ 	int flags = MS_SILENT;
+@@ -408,7 +408,7 @@ static inline void mount_block_root(char
+ 
+ void __init mount_root(char *root_device_name)
+ {
+-#ifdef CONFIG_MTD_ROOTFS_ROOT_DEV
++#ifdef CONFIG_UBIFS_ROOT
+ 	if (!mount_ubi_rootfs())
+ 		return;
+ #endif

target/linux/imx/cortexa9/config-default

@@ -51,3 +51,4 @@ CONFIG_SOC_IMX6=y
 CONFIG_SOC_IMX6Q=y
 CONFIG_SOC_IMX6SL=y
 CONFIG_SOC_IMX6SX=y
+CONFIG_UBIFS_ROOT=y

target/linux/layerscape/armv8_64b/config-6.6

@@ -801,6 +801,7 @@ CONFIG_TRANS_TABLE=y
 CONFIG_TREE_RCU=y
 CONFIG_TREE_SRCU=y
 CONFIG_UBIFS_FS=y
+CONFIG_UBIFS_ROOT=y
 # CONFIG_UCLAMP_TASK is not set
 CONFIG_UIO=y
 CONFIG_UIO_AEC=y