Kernel detects squashfs on mtd but fail to mount root vfs panic

Am tweaking server hardware. Site will be down for this weekend. You can use this google drive link for now.

Flash the initramfs-kernel-factory.img via Linksys UI. Then once openwrt loads, log in and flash squashfs-sysupgrade.bin.

You can ask questions here: Help with flashing Linksys EA8100 -MT7621

Thanks for the heads up. I installed initramfs-kernel-factory.img but now router LED is not turning on but it seems like router is turned on. With LAN connected I can ssh my router from linux but cant open in browser. But dont know how to proceed for next step.
I was also following installation process for other linksys routers and was trying to install Luci but i am getting this error "Only have 0kb available on filesystem /overlay, pkg luci needs 1"
Cannot install luci"
How should i go forward?

Did you flash squashfs-sysupgrade.bin in a ssh session after flashing initramfs-kernel-factory?

I didn’t do that as i couldn’t find out how to do that. Some pointers will be very helpful.
And now i managed to boot the router into its own firmware by restarting it 3 times so i also want to know how do i reboot into openwrt firmware when i would flash squashfs-sysupgrade.bin.

Scp the sysupgrade file into /tmp then follow the "Flash the new OpenWrt firmware" section in this page:

Contrary to what the page says, my ea8100 openwrt bin does not preserve settings across upgrades.