SK-AM64B: SK-AM64B serial console not responding to terminal

Hello Peter,

Are you following the steps in the SK-AM64B Quick Start Guide to set up serial communication?
https://dev.ti.com/tirex/explore/node?a=7qm9DIS__LATEST&node=A__ALqhtJgGIUvD4HS9SggrMA__am64x-devtools__FUz-xrs__LATEST

Regards,

Nick

Yes, I think I followed the directions correctly,  115200 baud, 8N1.  I use these same terminal settings to talk to many other development boards.

I'm beginning to think this is due to the way that the processor is booting. Perhaps, u-boot is built with the console disabled in such a way that it cannot be interrupted by the console.  Also, when linux tries to start it seems to hang on processes that it is trying to start and maybe that is why I cannot type into the login prompt.

It is unlikely that the usb-uart port is defective in such a way that it can send characters but not receive.

I also found that the board appears on the local network.

$ nmap -sP 192.168.1.1/24
Starting Nmap 7.80 ( https://nmap.org ) at 2024-10-30 09:06 EDT
Nmap scan report for am64xx-evm.lan (192.168.1.236)
Host is up (0.00034s latency).

and I was able to ssh into it.

$ ssh root@192.168.1.236
Linux am64xx-evm 6.6.32-k3-rt #1 SMP PREEMPT_RT Fri Aug  2 09:47:49 UTC 2024 aarch64

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.

Hello Peter,

Just to verify, are you booting with this filesystem image?
https://www.ti.com/tool/download/PROCESSOR-SDK-LINUX-RT-AM64X
tisdk-debian-trixie-rt-am64xx-evm.wic.xz  — 291076 K

When I tested on the yocto image, terminal connectivity worked exactly as expected:

// on my Linux PC
$  minicom -w -D /dev/ttyUSB1

// terminal opens
Welcome to minicom 2.8

OPTIONS: I18n
Port /dev/ttyUSB1, 17:53:12

Press CTRL-A Z for help on special keys


am64xx-evm login: [   21.990070] platform led-controller: deferred probe pending
[   21.990127] platform 20000000.i2c: deferred probe pending

am64xx-evm login: root
[   24.689257] audit: type=1006 audit(1713280219.894:2): pid=885 uid=0 old-auid=4294967295 auid=0 tty=(none) old-ses=4294967295 ses=1 res=1
[   24.690566] audit: type=1300 audit(1713280219.894:2): arch=c00000b7 syscall=64 success=yes exit=1 a0=8 a1=ffffdf0df5f8 a2=1 a3=1 items=0 ppid=1 pid=885 auid=0 uid=0 gid=0
 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=1 comm="(systemd)" exe="/usr/lib/systemd/systemd-executor" key=(null)
[   24.690601] audit: type=1327 audit(1713280219.894:2): proctitle="(systemd)"
root@am64xx-evm:~#
root@am64xx-evm:~# uname -a
Linux am64xx-evm 6.6.32-rt32-ti-rt-g04a9ad081f0f-dirty #1 SMP PREEMPT_RT Fri Jul 26 14:42:37 UTC 2024 aarch64 GNU/Linux
root@am64xx-evm:~# reboot -f
...
U-Boot SPL 2024.04-ti-gfda88f8bcea3 (Jul 26 2024 - 11:00:12 +0000)
SYSFW ABI: 4.0 (firmware rev 0x000a '10.0.8--v10.00.08 (Fiery Fox)')
Trying to boot from MMC2
Authentication passed
Authentication passed


U-Boot 2024.04-ti-gfda88f8bcea3 (Jul 26 2024 - 11:00:12 +0000)

SoC:   AM64X SR2.0 HS-FS
Model: Texas Instruments AM642 SK
Board: AM64B-SKEVM rev A
DRAM:  2 GiB
Core:  89 devices, 31 uclasses, devicetree: separate
NAND:  0 MiB
MMC:   mmc@fa00000: 1
Loading Environment from nowhere... OK
In:    serial@2800000
Out:   serial@2800000
Err:   serial@2800000
Failed to probe prueth driver
Net:   eth0: ethernet@8000000port@1, eth1: ethernet@8000000port@2
Hit any key to stop autoboot:  0
=>
=>

I am reassigning your thread to another team member more familiar with the Debian version of the SDK.

Regards,

Nick