Suppose the native BL33 bootloader code had unrestricted access to the u-boot shell. Might a memory patch to the running BL33 code be able to nop or toggle the engineering device status check?
Yes, if you can figure out a way to do a memory patch or get unrestricted access to u-boot, that opens up a number of possibilities.
Using Peacock on a rooted device
Unrelated, I was asked whether Peacock would work on the Cube with root. Peacock appears to have a number of security checks that will cause it to force close on a rooted device.
@bobpiesz made a Peacock mod that will work, but it requires disabling signature verification, and hiding Magisk.
What's needed:
Magisk / Magisk manager 24.0 or later
LPosed for Zygisk latest
CorePatch 2.2 (EN)
Modded Peacock app
1) Enable Zygisk in Magisk Manager settings
2) Go to Magisk Manager modules tab, install
LPosed for Zygisk, and enable it. If you don't see an LPosed icon on your Homescreen/Apps drawer after installation, use a filemanager (Total Commander, MiXplorer, etc) to navigate to /data/adb/lspd, and manually install manager.apk. Requires a reboot to become active.
3) Install
CorePatch 2.2 (EN) apk, this is the last version compatible with Android 7x-10x. Open CorePatch, grant SuperUser access when prompted, and make sure the second toggle is enabled
Disable Package Manager Signature Verification
. Open LPosed and enable CorePatch module. Reboot for CorePatch to become active.
4) Install
modded Peacock app, but don't open it yet.
5) Open Magisk Manager, go to settings, enable
Enforce DenyList
, go to
Configure Denylist
and add the Peacock app. Lastly in Magisk Manager settings,
hide the Magisk app
(give Magisk installation permission, then retry), give Magisk any new name.
Now Peacock will no longer force close. If it does force close, go into FireOS settings, apps list, and clear Peacock data & cache, and try to reopen.
A couple other Magisk / LPosed (Xposed) mods that people might find useful
Install
Google Services / AndroidTV Play Store (verified on Cube)
Full remote button remapping including recents & favorites, with
Xposed Edge (verified on Cube)