How to install an older OTA release in your Ubuntu Phone

We saw here how to change the channel of our Ubuntu Phone from stable to RC proposed, or whatever you want.

But, how could we downgrade the phone to a previous OTA? Setting the revision we want in the ubuntu-device-flash command :)

You need to know which revision is for what OTA and which device you have:

1. Know your device codename (Connect phone by USB and enable Developer Mode in Settings):

costales@dev:~$ adb shell grep ro.product.device /system/build.prop
ro.product.device=arale
# ro.build.product is obsolete; use ro.product.device
costales@dev:~$


2. Then, use that codename "arale" for knowing each available OTA - revision in the channel stable for your Meizu:

costales@dev:~$ ubuntu-device-flash query --device=arale --channel=ubuntu-touch/stable/meizu.en --list-images
1: description='ubuntu=20150602,device=20150522-a851049,custom=20150602-731-5-32,version=1'
2: description='ubuntu=20150611.3,device=20150608-6e66f3c,custom=20150602-731-5-32,version=2'
3: description='ubuntu=20150720,device=20150709-8965e37,custom=20150716-819-8-42,version=3'
4: description='ubuntu=20150825.1,device=20150818-0b38025,custom=20150814-887-8-46,version=4'
5: description='ubuntu=20151015,device=20150818-0b38025,custom=20150925-900-8-47,version=5'
6: description='ubuntu=20151015,device=20151016-0b38025,custom=20150925-900-8-47,version=6'
7: description='ubuntu=20151118.2,device=20151016-0b38025,custom=20151111-918-8-52,tag=OTA-8,version=7'
8: description='ubuntu=20151210,device=20151016-0b38025,custom=20151111-918-8-52,tag=OTA-8.5,version=8'
9: description='ubuntu=20160123.1,device=20160111-51982fc,custom=1452441600,tag=OTA-9,version=9'
10: description='ubuntu=20160217.1,device=20160111-51982fc,custom=1452441600,tag=OTA-9.1,version=10'
11: description='ubuntu=20160401.1,device=20160331-e143fc2,custom=20160324-945-18-69,tag=OTA-10,version=11'
12: description='ubuntu=20160408.4,device=20160331-e143fc2,custom=20160324-945-18-69,tag=OTA-10.1,version=12'
13: description='ubuntu=20160524.1,device=20160331-e143fc2,custom=20160504-975-19-6,tag=OTA-11,version=13'
costales@dev:~$ 

Then, for flashing the older stable OTA 10 in your MX4:

ubuntu-device-flash touch --revision 11 --channel=ubuntu-touch/stable/meizu.en

Thanks a lot to Joerg Berroth for his knowledge! |o/