Jim MacKenzie Posted February 23, 2019 Share Posted February 23, 2019 Hi, I have deployed a NanoPi Neo 4 and for the most part, I'm happy with it, but am having a peculiar problem. I am using the manufacturer-supplied serial console cable and USB adapter (via screen /dev/ttyUSBx 115200). Once the machine is properly booted, if I hit enter, I get a serial console as normal. However, I get garbage from u-boot (and presumably from the kernel boot messages). It looks just as if I have a speed mismatch. I have tried many other speeds (1500000, 230400, 57600, 38400, 19200, 9600) and none of these seem to work. What am I doing wrong? Or is the state of the box right now that u-boot sends garbage through the serial port? I'm having a bit a problem with the box (it may be power-related) and being able to see the console would be a huge help. Thanks! Jim Link to comment Share on other sites More sharing options...
martinayotte Posted February 23, 2019 Share Posted February 23, 2019 1 hour ago, Jim MacKenzie said: via screen /dev/ttyUSBx 115200 The RK3399 SoC is defaulted to 1500000 and the U-Boot too... Link to comment Share on other sites More sharing options...
Jim MacKenzie Posted February 23, 2019 Author Share Posted February 23, 2019 2 minutes ago, martinayotte said: The RK3399 SoC is defaulted to 1500000 and the U-Boot too... I tried that, and I still got garbage. I'll give it another go, though. Link to comment Share on other sites More sharing options...
Jim MacKenzie Posted February 23, 2019 Author Share Posted February 23, 2019 Confirmed, I get garbage at 1500000 bps as well. I also tried 230400, 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200 and 300, out of desperation. The UART/USB adapter says it's USB 2.0 but lsusb -v shows it's only connected at 1.1 speeds. I doubt this should matter - 1.1 can still handle 1.5Mbps - but thought I should mention it. Link to comment Share on other sites More sharing options...
Jim MacKenzie Posted February 24, 2019 Author Share Posted February 24, 2019 I got it working by moving the USB cable to another machine. Maybe it's some weird USB-port incompatibility with 1.5Mbps. (It used to be plugged into an old ARM box - the box that the new NanoPi is replacing - but is now plugged into a Core 2 Duo desktop, also running Linux.) I still don't get any kernel booting messages (any way to force this to happen?) but I see the u-boot messages, at least, and was able to diagnose my problem and get the NanoPi booted again. Link to comment Share on other sites More sharing options...
martinayotte Posted February 24, 2019 Share Posted February 24, 2019 14 hours ago, Jim MacKenzie said: I still don't get any kernel booting messages (any way to force this to happen?) If you mean that you don't see any kernel logs after "starting kernel", make sure that /boot/armbianEnv.txt have "console=serial" and "verbosity=7" ... 1 Link to comment Share on other sites More sharing options...
Jim MacKenzie Posted February 24, 2019 Author Share Posted February 24, 2019 17 minutes ago, martinayotte said: If you mean that you don't see any kernel logs after "starting kernel", make sure that /boot/armbianEnv.txt have "console=serial" and "verbosity=7" ... That's exactly what I mean. I'll make that tweak. Thanks! Link to comment Share on other sites More sharing options...
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