FOTA Strategy

Firmware Over-The-Air (FOTA) is built around a dedicated recovery image plus a scratch partition, all hosted on the SPI NAND.

See SPI NAND Partitioning for the layout reference.

The two Buildroot configurations

Configuration	Output	Purpose
`mds_network_player_fota_defconfig`	`uImage` + initramfs + DTB	Recovery system stored in the `fota` partition
`mds_network_player_defconfig`	`uImage`, `rootfs.ubifs`	Regular system stored in the `rootfs` partition

The FOTA system is intentionally minimal: an initramfs with the tools and shell scripts needed to flash a new rootfs and reboot — nothing else.

Boot decision

On power-up, U-Boot loads:

uImage (kernel) — taken from the fota partition.
The device tree from fota.
The kernel command line points the root at ubi0:rootfs (the main rootfs in the rootfs partition).

The kernel attaches both UBI volumes. The init that runs first is the FOTA initramfs:

If /data/.run.ota (a marker file) is found in the data partition, the FOTA script applies the new rootfs from data/rootfs.ubifs to the rootfs partition, then reboots.
Otherwise it switch_roots into the main rootfs and Linux boots as usual.

A typical U-Boot log:

** File not found .run.ota **
No OTA update found
Loading file '/boot/uImage' to addr 0x80000000...
Loading file '/boot/suniv-f1c200s-...dtb' to addr 0x80fe0000...
## Booting kernel from Legacy Image at 80000000 ...

First-time setup (bootstrap)

After the very first bootstrap (see Bootstrap), all UBI volumes are still empty. They have to be created and populated:

# 1. Format each NAND partition as UBI
ubiformat /dev/mtd1
ubiformat /dev/mtd2
ubiformat /dev/mtd3

# 2. Attach UBI to each partition
ubiattach -p /dev/mtd1
ubiattach -p /dev/mtd2
ubiattach -p /dev/mtd3

# 3. Create the volumes (one per partition, taking the full space)
ubimkvol /dev/ubi0 -N fota   -m
ubimkvol /dev/ubi1 -N rootfs -m
ubimkvol /dev/ubi2 -N data   -m

# 4. Mount and populate
mkdir -p /mnt/fota /mnt/rootfs /mnt/data
mount -t ubifs /dev/ubi0_0 /mnt/fota
mount -t ubifs /dev/ubi1_0 /mnt/rootfs
mount -t ubifs /dev/ubi2_0 /mnt/data

From the host, copy the recovery image and the rootfs into place:

# Recovery (fota) — kernel + DTB + env
scp -O out/fota/uImage                                              mds:/mnt/fota/uImage
scp -O out/fota/uboot.env                                           mds:/mnt/fota/uboot.env
scp -O out/fota/suniv-f1c200s-mds-network-streamer-v1.0.dtb         mds:/mnt/fota/

# Main rootfs (staged in data, then flashed into rootfs volume)
scp -O out/network_player/rootfs.ubifs                              mds:/mnt/data/rootfs.ubifs

Apply the rootfs to its UBI volume:

ubiupdatevol /dev/ubi1_0 /mnt/data/rootfs.ubifs

After this the board can boot end-to-end from NAND with the recovery in fota and the system in rootfs.

Open questions / TODO

The following items are tracked but not yet implemented:

Persist the U-Boot environment back into NAND (currently Loading Environment from nowhere).
Promote the layout to a proper A/B scheme with rootfs-a / rootfs-b volumes and atomic switch.