Linksys 8100v2, how to force flash on alternate partition?

Not talking about Advanced Reboot, as rebooting isn't an issue. On my 8100, the primary partition has OpenWRT 22.03.3 and when I tried to flash (sysupgrade), instead of flashing to the secondary/alternate/backup partition, it simply flashed on the primary one again. So how can I force it to flash onto the other partition?

I didn't check for your specific device, but for all other dual-boot devices that I have encountered, the answer is: you can't.

EDIT: I checked. OpenWrt can only be installed in the first partition, it completely ignores the second. This has the advantage that you can keep your OEM firmware in the second slot and can easily restore stock by booting the second image.

IMHO there is no advantage of a dual-firmware design for OpenWrt. The failsafe mode usually works very well, if you really mess up things, it's easy to recover.

commit comment

I would say there is a very significant advantage to this design, and it works well if well supported.

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Which one would that be?

Any member of the wrtpac family, mamba, cobra...

This, I believe, is the intended behavior. Current partition gets updated, the other partition is presumed to be a fallback.

I don't have experience with this model, but I did deal with a couple of prior Linksys models that had dual-partition architecture. If memory serves, you can boot into stock firmware using Advanced Reboot and repeat the initial install process. Basically, do it all over again the same way you did it the first time.

I have a Linksys EA3500, WRT1200AC and MR8300 that all say you're a liar (said in a humorous manner).

You just contradicted yourself. Is there no benefit, or is there? Dual-firmware design, if you try to upgrade and it fails, revert back to the working OpenWRT partition.

I don't own any Linksys device, but dual firmware does not work on any Realtek switch (neither D-Link nor TP-Link nor Zyxel nor Netgear) or the SERCOMM NA502/NA502S.

Anyway, for this device, the partition layout is hardcoded in the .dts and the second firmware partition is not used. The commit message linked above confirms that (although not directly). Please correct me if this has been changed since the initial commit.

I did not. Failsafe does not imply dual firmware, it is present on any OpenWrt device.

The only advantage I see for dual firmware would be a bad flash of the OpenWrt image - I never encountered one during regular use and I have had a lot of OpenWrt devices.

Just to clarify something, the part of calling you a liar was said with humor in mind. (Just in case it came off in the wrong way.)

I don't know how I managed to get both partitions flashed, which is why I was asking how to go about doing it. Would be great to be able to pick and choose, as well as know that if one attempt fails, it can fallback to the working one.

No worries, that was clear from your post :slight_smile:

I know that some models support flashing OpenWrt to both partitions. However, there needs to be a way to figure out during boot which partition OpenWrt is installed in. And since the partitions on the 8100v2 are hardcoded (at least, it seems so to me), it can only be installed to one partition.

The idea is that you boot to one partition and when you flash a new firmware file, it flashes to the other partition. Then if that flash fails, it reverts back to the known working partition. If it works though, the roles are "swapped," so that you always back a working failsafe partition, but it's not frozen to some version that might look like a dinosaur by comparison.

Wanted to be sure. If you ever saw the 2000's sitcom "George Lopez," it's from an episode where there was an earthquake. Benny is asking how much insurance would pay for a destroyed chimney and after the insurance guy left, George commented how she never had a chimney and she responded with a similar line, something about how there will be bricks on her lawn that says he's a liar. It was a very funny scene and comment. :rofl:

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So I checked again: The EA3500 is a Marvell Kirkwood device. There is a script in /lib/upgrade/linksys.h that takes care of flashing to the "correct" partition - see

The 8100v2 is a MT7621A device. There is also a /lib/upgrade/ shell script that should take care of partition handling, but this is not enabled for the 8100v2 - see here:

It is, for instance, enabled for the Alfa Networks Quad E4G device.

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I have tested several Linksys models (various targets), and each time the flash process is done, it's on the "other" partition. Even when sysupgrading.

Any of these amongst your tested devices?

  • e5600
  • e7350
  • ea6350-v4
  • ea7300-v1
  • ea7300-v2
  • ea7500-v2
  • ea8100-v1
  • ea8100-v2

yes, EA7300 v2

OK, then it should also work on the 8100v2, although I can't tell why (or why not). I'm only looking at the code...

Hi!) how to flash another partion on ea7500 v2?

Just flash a factory image. It should be on the "other" partition.
Nevertheless, if you are experimenting issues (reboot to Linksys firmware) than I encourage you to read the page for EA7300 v2 (yes 7300, it's not an error). I suspect that both devices share the same bootloader, and so the same boot issue.

ok, but you can make it so that there is openwrt on two partions?

sysupgrade twice (with the same image).

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