In this post we will cover how to connect your Mac to the warp using the serial console if your warp is programmed with Yocto.
There are two possible configurations:
- you have just the warp
- you have the warp docked to the interposer board.
In the case that you have only the warp board, the serial console will be accessible because the multi_gadget kernel module is loaded at boot time. Using the same MicroUSB cable that powers the board, after few seconds you will find in your Mac a device like:
/dev/tty.usbmodem14223
Next, you can use a terminal emulation program like minicom to open the serial console.
If you have only the warp, the terminal does not provide output until the module has been loaded. This means that you will not be able to access the boot loader stage.
In the case you have also the interposer board, just connect a MicroUSB to the “CONSOLE DEBUG” port.
After connecting, your Mac will show a device like:
/dev/tty.SLAB_USBtoUART[xx]
where xx is a two digit number that may vary depending on the dynamic device name allocation.
Having the interposer allows you to have access also to the U-Boot stage.
Just use a terminal emulation program like minicom to open such device.
Note: The warp board must also be powered on. While plugged into the interposer board, the warp does not require it’s own Micro USB connection. The interposer provides adequate power for both itself and the warp from a single Micro USB connection on the Console/Debug port. Ensure that the warp is powered on by pressing the “PUSH BTN 1 (PMIC PWR)” button on the interposer.
