Development tools for Zephyr on STM32Workbench for Zephyr: VS Code extension to set up, build, flash and debug Zephyr applications on STM32.Devicetree manager: browse, edit and visualize Zephyr devicetree, STM32CubeMX-like for Zephyr.
There is a typo in the original post: the attribute used for placing functions in ITCM must be attribute((.itcm_text)), not .itcm_ram. This may explain why the .itcm_text section is empty...