Some of you may be aware I’ve been in possession of John’s old Nexus 9 for a few months and for the most part it’s been doing what I have needed it to do while running the Marshmallow preview.
If you’re Nexus root whizzes, feel free to scoff at my prattling guide and move on. I’m an HTC EVO/M* background rooter and this was my first time taking on Marshmallow/a Nexus 9. Marshmallow was a little trickier than the previous versions.
Unfortunately when the Android 6.0 release was finalized, I ended up suddenly losing a lot of data on the tablet from apps that really need to get with cloud syncing. I hadn’t rooted the thing as there was no compelling reason for a device I use mostly for reading, but an elaborate camera setup I had configured got lost so it was time to root it so I could backup that data using Titanium Backup.
There are probably plenty of guides out there on how to root a WiFi HTC Nexus 9, this one assumes you are familiar with rooting things (why else are you here?) and assumes you probably have an HTC rooting background. As such you may want to look elsewhere for in-depth step-by-step instructions if you haven’t rooted things before.
If you’re a root pro – the differences between this and say an M9 are you need a new kernel, will have to get a SuperSU beta binary, and if you haven’t rooted something in a while enabling OEM unlocking is a somewhat new thing.
This works with the official Android 6.0 Marshmallow software as of October 27th, 2015. If you’re reading this much later than that, might want to check and see if it’s outdated. It might work with the LTE Nexus 9 but I don’t know.
This will probably wipe your device as a note. I came at this from a slightly different position with the bootloader already unlocked when I got it, so can’t say for sure. In other words, I started at step three today.
Prerequisites: have the proper files
- ADB (either the whole Android SDK or a fastboot/adb pack)
- A custom recovery
- A replacement kernel
- A copy of the beta SuperSU binary
- Potentially ADB drivers is your Nexus isn’t picking up
Step one: get developer access
Settings, about tablet, tap on Build Number until it says you’re a developer. Bam, you’re a developer.
Step two: unlock the bootloader
Settings, developer options, make sure OEM unlocking is slid to the right, make sure USB debugging is available. Plug your Nexus into a computer and if it asks if you want to allow it to USB debug say yes, always.
Reboot into bootloader by typing the command “adb reboot bootloader,” from wherever you stashed the Android SDK or your copy of ADB and Fastboot.
The command you’ll want to execute is “Fastboot OEM unlock” but I can’t tell you what it’ll say at this point because I unlocked it on a preview version a while back. I believe whisky was involved.
This will probably prompt you to erase everything. Your call really. Take the blue pill and you wake up in your bed tomorrow thinking this was all a dream. Take the red pill and you go further down the rabbit hole and you just realized Cowboy Curtis on Pee-Wee’s Playhouse was Morpheus in the Matrix.
Step three: flash the recovery
The command is “Fastboot flash recovery hereissometoast” where “hereissometoast” is whatever you placed the recovery that you downloaded. For me it would have been “Fastboot flash recovery \users\Paul\downloads\twrp-188.8.131.52-flounder.img” – wherever you downloaded it will be what you put.
After flashing the recovery I navigated on the tablet to recovery
Step four: backup time
You should be seeing a TWRP screen now. If not, flash again, try to get back. I noticed that if I rebooted the TWRP seemed to slide off replaced by the stock.
You’re going to be greeted with a request for whether you want to make a backup of the system in a read-only state. I’d advise yes if you want to be careful, but I had to choose no because I live life on the edge and really shouldn’t be trusted around electronics.
I mounted the system read/write, making any OTAs that will appear in the future fail, made a quick backup just in case something failed in the next steps, and proceeded.
Step five: let’s remove some security!
I pushed the SuperSU and kernel to the tablet from the command line like so:
adb push c:\users\paul\downloads\ElementalX-N9-4.00.zip /sdcard/
adb push c:\users\paul\downloads\BETA-SuperSU-v2.50.zip /sdcard/
Flash the kernel first. I went with all stock options. Then flash the SuperSU.
After that’s done reboot.
Step six: stomach drops as your tablet tells you it’s corrupted
You’ll see a warning over on the left that the tablet is corrupt and untrustworthy. Might be because it’s rooted. Ignore it. It’s like the HTC red text.
Boot will take slightly longer than usual, but still under two minutes. You should be up and running now, but can verify by downloading and launching SuperSU on the tablet.
Step seven: do something root worthy
So, you’ve made it this far. Undoubtedly I missed something. Let me know what I missed and I’ll include it in here. Screenshots appreciated as I’m working some from memory.