[BPI-R64] Turn ttyS0 into a normal serial port

I need to turn ttyS0 into a normal serial port and receive signals all the time. But when there is a signal input, the system cannot be started. I want to know what I should modify.

With ttyS0 you mean debug-uart? Which board? Why do you need this as normal serial (imho not possible so easy and you will loose your rescue-fallback if possible anyhow)? You have some on gpio header and if they are not enough you can use usb2uart adapters to get more

Bpir64, Ubuntu 18.04, I can’t find enough uarts from 40 pins

R64 has 2 uart on gpio-header,if you need more you can use usb2uart or i guess there are some chips providing uarts and connected via i2c or spi

Have added board to title…

Really? Where are they? Because I only found one before.

pins 8/10 and 11/13


i guess they need to be enabled in dts to be visible in system

I have done tests. It seems that 8/10 and 11/13 are the same. I can only use one of them. When I use one of them, the other will become invalid.

i guess you have to increase maximum/runtime uarts in your config…default is 1 (debuguart+ one from gpio)

Can you be more specific? I don’t know where to configure it. In fact, I’m a novice.:joy:

in kernels menuconfig or before in defconfig