OTA Framework and Implementation

[nfreq]

---

Build ZBot OTA System

source device/milkv-duos-ota-sd/boardconfig.sh 
source build/milkvsetup-ota.sh 
defconfig cv1813h_milkv_duos_ota_sd
clean_all
build_all

# generate three blank ext4 filesystems
------
dd if=/dev/zero of=install/soc_cv1813h_milkv_duos_ota_sd/env.ext4 bs=1k count=256
mkfs.ext4 install/soc_cv1813h_milkv_duos_ota_sd/env.ext4 

dd if=/dev/zero of=install/soc_cv1813h_milkv_duos_ota_sd/placeholder_staging.ext4 bs=1k count=300000
mkfs.ext4 install/soc_cv1813h_milkv_duos_ota_sd/placeholder_staging.ext4 

dd if=/dev/zero of=install/soc_cv1813h_milkv_duos_ota_sd/placeholder_data.ext4 bs=1k count=50000
mkfs.ext4 install/soc_cv1813h_milkv_duos_ota_sd/placeholder_data.ext4 

# should now have the following:
./install/soc_cv1813h_milkv_duos_ota_sd/env.ext4
./install/soc_cv1813h_milkv_duos_ota_sd/placeholder_data.ext4
./install/soc_cv1813h_milkv_duos_ota_sd/placeholder_staging.ext4
----

# generate the sd image file
pack_sd_image

# alternatively generate compressed image file for distribution
pack_sd_image_gz

# burn image to sd
Add wpa_supplicant.conf to boot parition

---

Build ZBot Main OS and perform OTA Updates

source device/milkv-duos-sd/boardconfig.sh 
source build/milkvsetup.sh 
defconfig cv1813h_milkv_duos_sd
clean_all
build_all
pack_sd_image
gen_swu_ota <version>
tools/zbot_updater.py update 192.168.42.1 install/<board>/zbot.swu

---

Parition Table
GPT/MBR Hybrid (Boot Partition UUID Set such that Mac/Windows will mount)

Upgraded Genimage to v18 (Support UUID Partition Types and Improved Hybrid Support)
(GPT Partition Table)
├── /dev/mmcblk0p1 (boot) [EFI System Partition, FAT32, 128M, Bootable]
├── /dev/mmcblk0p2 (env) [Linux, 256K]
├── /dev/mmcblk0p3 (otafs) [Linux, EXT4, 125M]
├── /dev/mmcblk0p4 (rootfs) [Linux, 275M]
├── /dev/mmcblk0p5 (data) [Linux, 50M]
└── /dev/mmcblk0p6 (staging) [Linux, 300M]

U-Boot Configured to Support Persistent Environment (ext4 backend via env partition)

Added data parition to seperate from rootfs. (config, weights, data)

---

OTA Environment Mechanics

Key Variables
---
rootfs=root=/dev/mmcblk0p4 rootwait rw   -- default rootfs location
otafs=root=/dev/mmcblk0p3 rootwait rw    -- default otafs location
root=root=/dev/mmcblk0p4 rootwait rw     -- booted partition

(this is the control variable)
next_boot = {otafs, rootfs}              -- next boot location

# example (boot into otafs)
fw_setenv next_boot otafs
reboot

boot-ota
boot-zbot

---

OTA Updater

# OTA CLI Tool
tools/zbot_updater.py update <host> <swu file>

SWUpdate Backend (Updated to v2022.12)

• listens on port 10000 (via websocket and http)
• stages firmware, writes raw image to partition, writes files, updates microcontrollers
• handles hw compatibility, sw version rules, hash validation and compressed images.

---

sw-description (generated via gen_swu_ota)

software = {
    version = "1.01";
    description = "Zeroth01 v1.01 Update";
    hardware_compatibility = ["1.0", "1.1"];
    images = (
        {
          filename = "rootfs.ext4.gz";
          device = "/dev/mmcblk0p4";
          type = "raw";
          sha256 = "2a603bae7d73c95f4bff20f775a487c1e336430a21e525777a2516c7f73d5a5f";
          compressed = "zlib";
        }
    );
}

---

Work in progress

• Update utility triggers rootfs to reboot into otafs for updates
• LCD / Local UI for update process (show progress, ask confirm to update etc.)
• Checking/Downloading update from github/gitlab (Zeroth team feedback)
• Move this to BR_EXTERNAL (shouldn't be entangled in buildroot source tree direclty)
• Add redundancy (u-boot env, otafs a/b, u-boot a/b) (ordered for priority)
• Security

[nfreq]

This PR is ready for internal team to start using. I will revisit with a new PR when we iron out the cloud based portion of the update mechanism