I don't have experience with any "smart" TVs, but my "DVD player" is running U-Boot and linux. If you download a "firmware upgrade" and run xxd or "strings" on

I don't have experience with any "smart" TVs, but my "DVD player" is running U-Boot and linux. If you download a "firmware upgrade" and run xxd or "strings" on it, it becomes pretty clear what OS is running. I strongly suspect many/most "smart" TVs are running linux. (My fairly ancient DVD+VCR player runs VxWorks.)