No serial console on debug uart after rootfs is mounted


#1

Hi,

I am facing a problem in getting serial console after userspace init.
I am not getting a debian shell prompt via debug uart.

But I am able to get a telnet session to it(on busybox rootfs).
So system is running. But debug console is routed to somewhere else.

I don’t have a HDMI monitor also.

Last message I am getting on uart console is

[ 11.343919] bootserver=255.255.255.255, rootserver=10.2.24.2, rootpath=
[ 11.351997] ALSA device list:
[ 11.355122] No soundcards found.
[ 11.373134] VFS: Mounted root (nfs filesystem) on device 0:16.
[ 11.379739] Freeing unused kernel memory: 1152K

Any idea why it is so?
I got a warning like this also. I think this warning has nothing to do with it.

kernel source: is from [https://github.com/96boards-hikey/linux/tree/hikey960-v4.9]

Kernel cmdline: console=tty0 console=ttyAMA6,115200n8 root=/dev/mmcblk0p2 rootwait rw efi=noruntime ip=10.2.24.25 no_console_suspend loglevel=8

Kernel version: Linux version 4.9.78-147534-gade06f4

Grub entry for this:
menuentry ‘Custom hikey960 boot’ {
linux /boot/Image console=tty0 console=ttyAMA6,115200n8 root=/dev/mmcblk0p2 rootwait rw quiet efi=noruntime ip=10.2.24.25 no_console_suspend loglevel=8
devicetree /boot/hi3660-hikey960.dtb
}

Rootfs from: linaro-stretch-developer-hikey-20180212-17.sd

Thanks in advance,
Sreenad.


Does Hikey960 support susped-to-mem with Linux 4.9 kernel?
#2

Hi @sreenad,

For HiKey/HiKey960 linaro builds, below kernel tree is being used:

Branch: hikey-v4.15

Please use the above tree and branch. There shouldn’t be any problem!

Thanks,
Mani


Warning during Hikey960 make defconfig
#3

For instructions on building and deploying the custom kernel, please refer below document:

Above doc is for HiKey but it should work for HiKey960 too. Only change required is to replace hi6220-hikey.dtb with hi3660-hikey960.dtb if you are using a different DTB.


#4

Thanks @Mani. I have build the kernel from suihkulokki/linux.

I got the serial console and linux shell prompt as well. :slight_smile:
But there is no USB support in this kernel.:neutral_face:

Anybody have any idea, why I am not getting serial console on 4.9 kernel from aosp repo and from 96boards-hikey github repo:thinking:
Then, how other kernel developers are working? :thinking:
I am curious to know. :ear:

Regards,
Sreenad.


#5

@sreenad

There is no USB support for HiKey960 yet!