Serial Port Console doesn't response Keyboard Input

I have a IMX6 setup and use TTL-RS232-3v3 connect to serial console port, the boot up couldn’t stop as I press any key on keyboard, it kept booting from mmc and I couldn’t update firmware. I tried to turn on echo on the terminal and saw the input, but serial console couldn’t take any input from keyboard. I followed the instruction but it stuck here, not sure what was wrong on the setup. I also tried short the TX with RX lines, it showed me more booting information till the prompt for login.

"Digi Embedded Yocto 2.0-r4 ccimx6sbc /dev/ttymxc3
ccimx6sbc login: "

Here is the information from the booting:

U-Boot dub-2015.04-r5.4+gdbf8184 (Jun 01 2017 - 20:17:59)

CPU: Freescale i.MX6Q rev1.5 1200 MHz (running at 792 MHz)
CPU: Extended Commercial temperature grade (-20C to 105C) at 42C
Reset cause: POR
I2C: ready
DRAM: 1 GiB
MMC: FSL_SDHC: 0 (eMMC), FSL_SDHC: 1
In: serial
Out: serial
Err: serial
ConnectCore 6 SOM variant 0x02: Consumer quad-core 1.2GHz, 4GB eMMC, 1GB DDR3, -20/+70C, Wireless, Bluetooth, Kinetis
Board: ConnectCore 6 SBC, version 3, ID 129
Boot device: MMC4
PMIC: DA9063, Device: 0x61, Variant: 0x60, Customer: 0x00, Config: 0x56
t: FEC [PRIME]
0t any key to stop autoboot: 1
=>
=>
=>
=> U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.04-r5.4+gdbf U-Boot dub-2015.

I suspect that you may have turned on hardware or software flow control on the PC terminal software. Please make sure you have disabled it or try a different terminal emulation program. If that is not an issue, please check the integrity of the RX line of the serial cable.

Our keyboard issues are the same for both of us. I’m having trouble getting one of our servers to start up. When I turned on the server, I utilized a serial connection to inspect it. It won’t let me type anything. I have already removed the battery, but it had no impact. I was unable to come up with a solution. Suddenly, I found a useful website about keyboards. You should also go here and read some articles that might be helpful to you.