I have searched a lot on internet and tried all suggested solutions like criss-cross connection, checking loose connections, changing baud_rates and using GND connection for UART, but nothing seems to work so far. Moreover most of the previous solution seekers were using Raspbian, whereas I am not. Hence, putting this question to get scenario specific solutions. I do not have resources to do any HW debugging, but assuming my RPi3 is not faulty.
This is first time I am using RPi3 (after years on beaglebone), so please do not assume anything.
I was trying to boot U-boot on RPi3.
I created a FAT partition on SD card and copied all the .dat, .elf and bootcode.bin files in the /boot folder on SD card. These firmware files were copied from the official Raspberry pi firmware Github repo.
I compiled U-boot and copied u-boot.bin file on the SDCard. I have created the following
config.txt file on SD card to pick uboot binary by the firmware :
U-boot logs are coming fine on HDMI , but I get garbage characters on Minicom (set at 115200, 8N1).
I am using the FTDI 232R-3V3 cable and have connected the RX, TX and GND on pins 6, 8 and 10 (criss-cross connection). HDMI port is also connected.
What could be the reason for this? I read here that BT operation could interfere, but I am not sure if that is applicable to me since I am not using Raspbian and only loading U-boot. If this is the case, how can I fix it? What other things I can try apart from mentioned at the top?