Missing Free RTOS debug output on UART_B

I’m currently trying to get the Free RTOS hello_world.elf example running. For this I tried deployment over the linux and did the following

root@colibri-imx7:~# ubiupdatevol /dev/ubi0_2  hello_world.elf

Colibri iMX7 # setenv m4boot 'ubi read ${loadaddr} m4firmware && bootaux ${loadaddr}'
Colibri iMX7 # saveenv

After the reboot I got the expected boot log on UART_A that Free RTOS was booted:

Read 0 bytes from volume m4firmware to 80800000
No size specified -> Using max size (87677)
## Starting auxiliary core at 0x1F0002E1 ...
Read 0 bytes from volume kernel to 81000000
No size specified -> Using max size (5114608)
Read 0 bytes from volume dtb to 82000000
No size specified -> Using max size (45016)

After I didn’t get any output from the UART_B I added the following boot options:

Colibri iMX7 # setenv defargs clk_ignore_unused
Colibri iMX7 # setenv fdt_fixup 'fdt addr ${fdt_addr_r} && fdt rm /soc/aips-bus@30800000/spba-bus@30800000/serial@30890000'
Colibri iMX7 # saveenv

Still nothing on UART_B. Also attached the cable on UART_A to make sure there is no issue with the cable.

Here is log of “printenv” in the boot loader. I also checked that the options were saved.
printenv log

It seems that the precompiled version of the hello_world.elf file I used for testing was compiled with the debugging disabled. It would maybe make sense to ship the debug version of the hello_world.elf file (I used this package Colibri-VF61-M4_FreeRTOS_1.2-20170407).

Hallo Andri,
is it working now? What do you mean with the debug version of the hello_world.elf file?

Hallo Jaski. Yes it works now with the version I compiled myself. As far as I could see the demo application has 2 build modes ‘Release’ and ‘Debug’. The ‘Release’ build is optimized without any output on the serial console, but with the ‘Debug’ build I get the expected “Hello World!” output. In the mentioned package there seems to be the ‘Release’ build that won’t output anything.

hello andri, thanks for the feedback.