Hikey960 not able to access linux console

Hello everyone,

I have flashed my Hikey960 board with latest images using linux host by changing to fastboot mode.
I used the below commands and download the images from the link:

$ sudo fastboot flash ptable prm_ptable.img
$ sudo fastboot flash fastboot l-loader.bin
$ sudo fastboot flash fip fip.bin
$ sudo fastboot reboot-bootloader
$ sudo fastboot flash boot boot-linaro-stretch-developer-hikey-*.img
$ sudo fastboot flash system rootfs-linaro-stretch-developer-hikey-*.img

I did not run any other command other than these and all of them passed with status OKAY.

I am able to boot linux and see the logs on the console. But I am not able to access the board using UART.
I am using a in-house UART to USB converter which seems to be working reliably since I am able to read the logs easily using minicom or screen utility.

I am really not sure what I am missing in the process. any pointers would help!

Thanks,
Achyut

What I/O voltage level your converter uses? 96boards consumer edition I/O are 1.8V… you need to check compatibility

Converter uses 1.8V voltage level. I am clearly able to see the boot-logs on my console. Also while booting up I am able to communicate with hikey using my keyboard to select options, I used that method to validate if all my connectors are working. But once the board is booted up I am not able to get into the console.

Log snippet towards the end of the log:
Debian GNU/Linux 9 linaro-developer ttyAMA6

[ 6.332210] mmc_host mmc1: Bus speed (slot 0) = 25000000Hz (slot req 25000000Hz, actual 25000000HZ div = 0)
linaro-developer login: root (automatic login)

Last login: Thu Nov 3 17:16:43 UTC 2016 on ttyAMA6
Linux linaro-developer 4.19.5-hikey #26 SMP PREEMPT Sun Sep 8 01:23:41 UTC 2019 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.
root@linaro-developer:~# [ 7.100141] wlcore: PHY firmware version: Rev 8.2.0.0.240
[ 7.289206] wlcore: firmware booted (Rev 8.9.0.0.76)
[ 7.376415] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 7.391192] wlcore: down
[ 8.481554] random: crng init done
[ 8.484997] random: 7 urandom warning(s) missed due to ratelimiting
[ 12.100334] wlcore: ERROR timeout waiting for the hardware to complete initialization
[ 12.231982] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
[ 12.351863] mmc_host mmc1: Bus speed (slot 0) = 25000000Hz (slot req 25000000Hz, actual 25000000HZ div = 0)
[ 13.394492] wlcore: PHY firmware version: Rev 8.2.0.0.240
[ 14.010441] wlcore: firmware booted (Rev 8.9.0.0.76)
[ 14.520735] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 14.665048] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready

Thanks
Achyut

@Achyut_Hegde

Try disabling the hardware/software flow control in your serial emulator. With flow control enabled, you can still access the UEFI console but not the linux one.

@Mani Thank you for the suggestion.
Is there a preferred utility/OS to use Hikey960?
I have tried on MobaXterm on Windows and also Minicom on Linux.
In both the cases, by disabling flow control. But no luck over that front.

Any other handy tips which can be helpful.

I usually run microcom (microcom -s 115200 -p /dev/ttyUSB0), but I don’t see why it would work better than others.

@Loic As suspected, that is not helping either.
One thing is very clear. After booting the OS, it is blocking keyboard input. It could be missing drivers? Not sure though

In the post above I see the links for UEFI build which are stale as of now. Could you point me to the latest binaries which I can download and flash. I want to give a try with that.

Thanks, Achyut

@Achyut_Hegde The latest UEFI binaries are here: https://snapshots.linaro.org/reference-platform/components/uefi-staging/latest/hikey960/release/

@Mani Thank you for the binaries. But the result remains the same. I am able to see the UEFI options in the GRUB menu and easily navigate with it. But once the boot-up finishes and logs in (on its own) not able access the console.

Hello
Looks like the current requirements for the UART pins were not met on the FTDI converter I am using. After we moved the operating voltage to 3.3V (on the converter) I am able to login and operate well. Thank you for the support.
Have a great week ahead!
Achyut