7 replies to this topic

[matjmonk]

Question for you experts (and you know who you are  ), are there any potential issues with rolling back to 5.01 from 5.1? I know these are Nexus devices but we've seen issues in the past on other unlocked devices where you couldn't rollback to a previous release without serious problems such as soft/hard bricking of devices. Now to forestall the questions, the reason I want to try this is that I had a Satan's abode of a time getting 5.1 to install on my Nx6 using the normal installation methods of running the flash-all.bat file and flashing each file manually (no errors reported anytime except for the normal "file doesn't contain system.img") and finally ended up having to completely wipe the device and format the system partition to get things to work. So now I need to do some experimentation so that I can get the process down before trying to upgrade the SO's Nx6 so that I don't have to face the Wrath of Kahn if I end up losing any of her data. I've done some reading on some of the "other" Android sites but the information is a bit conflicting where some folks say you can and other say no it causes bricks so I thought I would ask the friendly folks here!

 

[cmh714]

I had no issues whatsoever upgrading from 5.0.2 to 5.1 using Sams HoN, which I would recommend you use rather than the flash-all scripts that come with the files.

 

As for downgrading, from everything I have read over on xda, you need to be extremely careful as many seem to be locking themselves out of their device.....5.1 automatically resets the OEM Lock setting in the ROM preventing you from flashing. So before flashing anything you need to make sure the setting in Developer options is turned on. At least thats what I am reading.....

[matjmonk]

I had no issues whatsoever upgrading from 5.0.2 to 5.1 using Sams HoN, which I would recommend you use rather than the flash-all scripts that come with the files.

 

As for downgrading, from everything I have read over on xda, you need to be extremely careful as many seem to be locking themselves out of their device.....5.1 automatically resets the OEM Lock setting in the ROM preventing you from flashing. So before flashing anything you need to make sure the setting in Developer options is turned on. At least thats what I am reading.....

Yeah, I read a few of those "reports" also but that shouldn't affect anyone unless you try to relock your bootloader, right?

[cmh714]

no what seems to be happening is even though you have an unlocked bootloader (as in you can see that in the bootloader screen - status code 3), 5.1 automatically ALWAYS resets the "switch" under Developer options. This is done for the new security stuff.

 

It seems because the software switch is disabled, if you try and flash you get the brick. In particular it seems to be happening on CM12 because I guess they flash the bootloader. I dont use CM so dont really know.

 

Just to be more than careful, before you flash anything, I would make sure that the software switch is enabled in Developer options, reboot immediately to bootloader/TWRP and flash. I think thats the safe method.

 

Curious to hear from others....

[matjmonk]

I've been flashing a few kernels and two different custom ROMS since the upgrade to 5.1 without any problems but I'm a bit concerned now that the "new" 5.1 image is out and really need to find out about downgrading to 5.01 to test the update process. I had never run into issues with flashing the factory images before this update and I've done it on two Nx6's and two N7(2013) just something weird happened this time.

[SamuriHL]

Downgrading right now isn't safe.  Attempting to flash the bootloader will brick the phone.  And while there is a very lengthy, painful method for unbricking it, I really don't recommend you go down this path.  If you skip flashing the bootloader, it MIGHT be possible but I don't have any confirmation on that.  I can upgrade the House of Nexus to ask if you want to skip the bootloader flashing if someone wants to try it, but, the massive warning here is that I'll take no responsibility whatsoever to what happens to your device if you do.

[matjmonk]

Downgrading right now isn't safe.  Attempting to flash the bootloader will brick the phone.  And while there is a very lengthy, painful method for unbricking it, I really don't recommend you go down this path.  If you skip flashing the bootloader, it MIGHT be possible but I don't have any confirmation on that.  I can upgrade the House of Nexus to ask if you want to skip the bootloader flashing if someone wants to try it, but, the massive warning here is that I'll take no responsibility whatsoever to what happens to your device if you do.

 

Yeah, I've been doing a bit more reading since I posted the question and I think downgrading is really not a safe thing to do even if these devices are supposed to be Nexuses! It's sort of a moot (see what I did there?) point anyway since we have that fabulous, magical unicorn tool out there called "House of Nexus" which I used to flash both Shamus to 5.1E this weekend and everything went off without a hitch.

[SamuriHL]

The latest version of the HoN allows you to skip flashing the bootloader. In theory this should allow one to downgrade safely, but, it is as yet untested. I don't know how safe these devices really are at this point.