Hi bism,
I just went through the procedure to update a Linksys WRT1200AC, this is - essentially - the "marketed to hobby users" variant of the "marketed to corporate types" EA7500v2
Like the EA this uses Linksys's dual-partition nonsense scheme.
This flashed the factory-to-openwrt firmware with no complaints then booted into openwrt. I then ran the openwrt sysupgrade version and it flashed with no complaints then rebooted. I then logged in and loaded luci-app-advanced-reboot which displayed that both partitions had OpenWRT loaded on them.
So, I AM familiar with the process to get OpenWRT on both partitions of a Linksys device that uses that dual partition scheme.
What I stated was that with the EA7500 v2 it's impossible to get openWRT on partition 2 from OpenWRT because UNLIKE the Linksys WRT1200AC, OpenWRT on the EA7500v2 ---NEVER--- flashes to partition 2 - the "alternate partition"
This is a bug. It's not something that hints from you are going to help me or anyone else. Only additional developer attention to the EA7500v2 firmware is going to fix this.
There are two major problems here:
First, leaving the Linksys EA7500 v2 with the Linksys firmware on partition 2 means leaving a "landmine" in the device. At any given time a power failure or other bug could cause the device to reboot itself into the factory firmware. In which case, the device immediately becomes remotely inaccessible. Furthermore it then becomes a serious problem to get it changed to boot back into openwrt on partition 1. You have to physically be at the device to fix it.
With the WRT1200AC, if a bug or power failure or whatever happens that causes the device to switch active partitions is triggered, the device is failureproof - it will merely boot into OpenWRT again - on the alternate partition.
Second, the documentation for the EA7500v2 does not mention this. The techdata for this device is here:
[OpenWrt Wiki] Techdata: Linksys EA7500 v2
It refers to this following thread for install instructions:
OpenWrt installation on Linksys EA7500v2 - Installing and Using OpenWrt - OpenWrt Forum
That thread is antique, it says the firmware is in beta, there's no luci for it, in the first post. All of that is wrong now.
The documentation for the WRT1200AC, located here:
[OpenWrt Wiki] Linksys WRT1200AC
is beautiful. It's clear, explains everything, and is accurate.
By contrast the EA7500v2 info is buried in hundreds of posts that are flat out wrong.
It took me 15 minutes to convert a WRT1200AC over to OpenWRT and get OpenWRT on both partitions.
It took me 4-5 hours to figure out that it was impossible to get OpenWRT on partition 2 of an EA7500v2 from OpenWRT. I read instructions. But that data was simply not there. And most of the posting on this are from people who have never actually done this and are just assuming the EA7500v2 works the same way as the WRT1200ACC because they assume just because it's a linksys device with 2 partitions all of those work the same way with openwrt.
Your response to me, here, point 2 is pretty much wrong because you don't specify this.
If you had said:
"On this EA7500v2 openwrt can only boot from part 1" it might have been accurate.
But what you said is wrong for the WRT1200AC. OpenWRT can boot from either partition on that device. It may also even be wrong for the EA7500v2 - if, that is, it was possible to install OpenWRT on partition 2. But it's not, so there's no way to check.
As for your point #3 - that is also, likely, accurate. But, a garden-variety stock EA7500v2 is going to come booting from partition 1. And the stock firmware has no way to show what partition the EA7500v2 is booted from. The implication is that you can do 2 successive installs from factory firmware and no matter what partition you are booted from it will work - except when I tried this - it failed. When I was booted from factory firmware on partition 1, the factory firmware refused to take the openwrt load giving a non-specific error. Of course, I did not know at the time what partition I was booted from, I did not know about all this requirement to have it be on partition 1 and so on - because that was not on the doc page for the device.
Hopefully you see how this is a problem. This post is an attempt to explain this. I've had probably just updated the techdata doc page for the EA7500v2 - except that the OpenWRT project doesn't seem to allow updating of doc pages.
It would be far better for the EA7500v2 developer to update dts or fix whatever this bug is that is making it not work like the majority of linksys dual partition devices.