wait the minute, but this means, that owners of RockPro64 were exposing their boards to risk of damage all the time, since the Pi-2 bus UART pins are connected to the same 1.8/3.0V APIO4 domain. and the USB/UART adapter sold is 3.3/5V. did I understand it right and what @tllim can tell?
PS. Funny, the schematics states that SDMMC0 domain is also 1.8/3.0V, but that would be plainly stupid, right, it's probably a typo, since SD cards expect 3.3V at the beginning of operation. it was not enough for rockchip to introduce an insane 1.5Mbaud/s baud rate, it yet needed to set UART2 into an uncommon voltage.
PS. Funny, the schematics states that SDMMC0 domain is also 1.8/3.0V, but that would be plainly stupid, right, it's probably a typo, since SD cards expect 3.3V at the beginning of operation. it was not enough for rockchip to introduce an insane 1.5Mbaud/s baud rate, it yet needed to set UART2 into an uncommon voltage.
ANT - my hobby OS for x86 and ARM.