No command line interface on HDMI but kernel logs printed

Question

I'm currently trying to build my own custom Linux OS for my Raspberry Pi 3 and am experiencing some trouble.

I'm using buildroot v2018_2.

I configured the system using make raspberrypi3_defconfig

Then just changed the following options :

• C library : use glibc instead of uClibc-ng
• Increased filesystem size from 60M to 100M
• Add password root to root user under [*] Enable root login with password

After compiling, flashing the generated sdcard.img and booting, I can see kernel logs on the HDMI connected screen.

However after booting, the OS doesn't propose any prompt on the HDMI screen and I'm stuck here.

I know that the system is not freezed because I can see kernel logs if I plug/unplug my keyboard.

I suppose that the console is connected to the UART and only kernel logs are sent to HDMI port.

However I can't find how to force console prompt on HDMI.

Here are my config.txt and cmdline :

---

$ cat config.txt
# Please note that this is only a sample, we recommend you to change it to fit
# your needs.
# You should override this file using a post-build script.
# See http://buildroot.org/manual.html#rootfs-custom
# and http://elinux.org/RPiconfig for a description of config.txt syntax

kernel=zImage

# To use an external initramfs file
#initramfs rootfs.cpio.gz

# Disable overscan assuming the display supports displaying the full resolution
# If the text shown on the screen disappears off the edge, comment this out
disable_overscan=1

# How much memory in MB to assign to the GPU on Pi models having
# 256, 512 or 1024 MB total memory
gpu_mem_256=100
gpu_mem_512=100
gpu_mem_1024=100

# fixes rpi3 ttyAMA0 serial console
dtoverlay=pi3-miniuart-bt

---

$ cat cmdline
root=/dev/mmcblk0p2 rootwait console=tty1 console=ttyAMA0,115200

---

I didn't change any configuration in kernel and I'm using the one from raspberry-pi github repository.

Does someone know how I could get a prompt on the HDMI screen ?

Answer 1

Add a line as follows to your /etc/inittab:

1:2345:respawn:/sbin/getty 38400 tty1

but perhaps your speed should be 115200 iso 38400

Answer 2

Thanks to @Gerard H. Pille and his clue about /etc/inittab file, I could find a solution which is described here

Seems that for having HDMI console, two tricks have to be done:

• console=tty1 shall be after console=ttyAMA0,115200 in cmdline.txt
• In /etc/inittab only one console in enabled.

There may have a better solution which allow to have several getty into /etc/inittab but this solution is sufficient for me right now.