usage:
1. Connect Jlink, start JLinkGDBServer
JLinkGDBServer -if SWD -device stm32h743zi -speed 16000
2. Listen to the RTT port data and forward it to the virtual serial port
sudo socat -d -d PTY,link=/dev/ttyRTT0,raw,ignoreeof TCP:127.0.0.1:19021,reuseaddr
3. Read serial data
minicom -D /dev/ttyRTT0
Performance:(STM32H743, 400MHZ)
time "dd if=/dev/zero of=/dev/console bs=512 count=2048"
6.67 sec 157KB/s
Signed-off-by: yinshengkai <yinshengkai@xiaomi.com>