How to access serial console from OSX?
I bought a small circuit kit based on CiLabs CP2102.
http://www2.strawberry-linux.com/products/usbserial/
I got a OSX device driver from CiLabs.
And I use "Zterm" with this serial port.
The virtual serial port feels slower for this signal sending.
So I recommend to use PCs to rewrite its firmwares.