warning: attempt to assign the value '8' to the undefined symbol LV_Z_MEM_POOL_NUMBER_BLOCKS when upgrading toolchain to 2.6.0

[lcj]

I was just updating a the nrf Connect toolchain version from 2.5.2 to 2.6 and got this error message:

warning: attempt to assign the value '8' to the undefined symbol LV_Z_MEM_POOL_NUMBER_BLOCKS

[r0n9]

Can you attach the code as well as the warning message? Normally, in front of the error/warning message, there are file name and line information, if you use VSCode, you can hold the ctrl + mouse left key, and the IDE will navigate you to the code that generates the error/warning message.

[lcj]

CONFIG_LV_Z_MEM_POOL_NUMBER_BLOCKS=8

in the prj.conf

[ovrebekk]

Hi Leo

It seems the way the LVGL heap is configured is handled a bit differently in the latest version. 

In v2.5.2 the heap was scaled based on the LV_Z_MEM_POOL_MAX_SIZE and LV_Z_MEM_POOL_NUMBER_BLOCKS parameters as seen here.

In the later version this was simplified to use just a single parameter, LV_Z_MEM_POOL_SIZE, as seen here. 

In other words you should change your project configuration to use this new parameter. 

The commit log provides a bit more context:
https://github.com/nrfconnect/sdk-zephyr/commit/c7f8033f2b982a0d5548da458e00bee2e3a19502

Best regards
Torbjørn

[lcj]

That was a great answer, Torbjorn! Thank you. I changed the value to:

CONFIG_LV_Z_MEM_POOL_SIZE=16384

as it had in the commit log you link you provided in the samples/subsys/display/lvgl/prj.conf:

[ovrebekk]

Glad I could help Leo

Good find on the prj.conf file, with that configuration the total size should be the same. 

Best regards
Torbjørn