@n3o
....... Serial UART (configured at 115200 bps, not 1.5Mbps!) .... that means serial output logs
if really you have read CAREFULLY the first post you should have read this too !
Anyway here is described all, exactly in the first post
if somethings is still not clear, here is not a ready food store but you should proceed by trials and errors, andmostly study by yourself
And you didn't even read the post of another user:
since you DON'T HAVE a big chip beside the cpu, then you have nand or emmc. Easy , isn't it
Multitool will say what it is, if a emmc or a nand
But you come back again asking and asking, and asking again
This usually is not a right approach to a forum