[gcb0]

almost no Android phone allows custom os! understands this.

all Samsung phones can only be flashed because someone leaked a internal tool. and still, there must be a huge community effort to get the kernel and drives for each model.

now keep in mind that this huge community effort doesn't exist even for for-developers v phones, such was the case with the moto x dev edition. with phones like fire, it's practically non existent!

Android devices are not open by any means. they just have a lovely stubborn community.