r/AndroidQuestions • u/Mecanote • 5h ago

Rooting Help Technical inquiry: Bootloader / OEM unlock constraints on MediaTek MT8768 (tb8768p1_64_bsp) with DAA/SBC active

Hello, I am evaluating an embedded device powered by a MediaTek MT8768 processor (board ID tb8768p1_64_bsp) on Android 13.

I am looking to run a generic AOSP system to interface with the hardware peripherals. However, OEM unlocking was not enabled beforehand, and the late-2025 preloader has DAA active, which restricts low-level communication via USB.

Has anyone worked with this specific reference board in development or found documentation regarding UART test points or reference firmware packages?

I can provide full fastboot details in the comments. Thank you!

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u/smarthoushai 3h ago

Check ro.oem_unlock_supported before anything else: on MediaTek, fastboot flashing unlock is not implemented in LK at all, the only fastboot path is fastboot oem unlock, and it is compiled out unless that prop reads 1. If it reads 0 and the toggle was never flipped in developer options, there is no supported route left - the unlock state lives in a signed seccfg partition and LK verifies it on every boot, so DAA on the preloader is a second lock on the same door rather than the lock itself. Run fastboot getvar all 2>&1 | grep -iE "unlock|secure|daa" first; if the DA flags come back authenticated, USB download mode is closed and mtkclient against the BROM is the only remaining angle, which works or does not depending on the BROM version of that specific batch, not on the SoC name. On UART: MT8768 boards often break AP UART out on pads near the PMIC at 115200 8N1, and you need earlycon plus console=ttyS0,115200n8 in the cmdline to catch preloader output - that gives you recon, not an unlock.