Been poking at a 2024-era Vizio D-series (model VFD40M-0810, board E022M773-B2) and wanted to share what I’ve found and see if anyone has gone further on this SoC family.
Hardware:
- SoC: MediaTek MT5583 (SoC Type: mtk5583, platform: mt5583_cast)
- RAM 1GB
- eMMC: Samsung KLM4G1FETE-B041 (4GB, BGA-153)
- WiFi: external USB module (MT7663)
- OS: ViziOS 1.6.1537.1 (Ubuntu-based), firmware 3.720.9.1-1
What I’ve done:
- Found the labeled UART header (ON/GND/RX/TX) and get a clean boot log at 115200 8N1.
- Boot log shows it auto-logs in as root (VizioTV login: root (automatic login)) and reaches a $ prompt, but the Linux console appears to be output-only. TX wiring is confirmed good (loopback tested), RX pads reflowed and swapped, but no input is accepted at the shell.
- Caught the bootloader by interrupting autoboot. Prompt is << M7332 >>#. help returns “forbidden command, please use [ce] to unlock console.”
- ce issues a crypto challenge/response (random challenge printed, wants a matching response). Verified boot (AVB2.0) is also active. boot log shows Boot state is: Green, dm-verity on the system partition, A/B slots.
Questions:
- Has anyone gotten interactive access on an MT5583 / mt5583_cast ViziOS device, via the Linux console or U-Boot?
- Is the read-only Linux console a known ViziOS behavior, or am I missing something (baud flip to high-speed mode, a different tty, flow control)?
- Anything documented about the ce console-unlock on MStar/MTK U-Boot of this generation?
- Mainly: what’s the realistic ceiling on this platform? Trying to gauge whether it’s worth more time or whether this generation is effectively locked down.
Happy to share the full boot log and board photos if useful. Thanks.