Using BufferedSerial through DMA

How can I use a BufferedSerial through DMA, any sample?

Sadly, Mbed’s serial APIs (buffered and unbuffered) are pretty much interrupt only. There are a few targets that implement them with DMA, such as nrf52, but most targets don’t. There’s also a separate “async serial” API, different from buffered / unbuffered serial, which can sometimes have DMA support.