hno has extracted and part-reverse-engineered the eGON boot ROM, it's clearly visible and available as the allwinner engineers didn't have time (or funding) to rush out anything other than what you see. imagine the shit-storm that would occur if they tried. you
really think that in today's cut-throat market they'd even
remotely risk "being found out"?
no, the chances of them making a glaring and incompetent accidental mistake that compromises on security are far, far higher than them getting involved in deliberately adding malicious spying code into the device.
you have to remember that the A20 was designed along "unbrickable" lines, so that they could help out incompetent OEMs and ODMs who took it on themselves to "experiment" by making random changes to the design. any kind of DRM would be a serious impediment to that... so they didn't add any.