Hello everyone. i'm hoping i can get some help with something i have been working off and on for a while. I have a SABRESD i.MX 6Dual/6Quad on a custom board from some OEM manufacturer. A few of them actually. I want to follow this tutorial to put linux on it. Looks pretty straight fwd. The problem i'm having is im unable to connect to the serial port to stop the U-Boot process if there is one at all. Currently there is Android on it so it's probably Fastboot. I'm guessing that the custom board does not allow a serial connection so it's not tampered with. I found what i think is a tx/rx on the board that connects to the chip for development.
Here is the pinout of the connection to the chip. the far left and right are vcc and ground while the two in the center connect to the chip.
and the headers i soldered onto it
Sorry for the noob questions. This is all very new to me and this is all i have managed to put together. If there is indeed Fastboot on it, is there a way i can flash U-boot without access to the serial connection that will later have a serial connection for me to connect to?