tfm: Add zephyr native ns_interface and logging function

[oyvindronningstad]

To allow using TFM NS interface without enabling CMSIS_RTOS support.
And to allow using TFM ns code that uses logging.

Signed-off-by: Øyvind Rønningstad [email protected]

[tejlmand]

Why is this a zephyr_sources ?
Does it really belong in the zephyr lib.

[oyvindronningstad]

It is part of the nonsecure image, to help interfacing with tfm.

[oyvindronningstad]

Merged as part of #33510.

[tejlmand]

Merged as part of #33510.

Seems that nullified my comment 😆

[ioannisg]

Merged as part of #33510.

Seems that nullified my comment 😆

I think this source is part of zephyr lib, @tejlmand. But I guess @oyvindronningstad could still answer, regardless of the change being already merged. :)

[oyvindronningstad]

I just wanted to stop/redirect more comments on this. I will answer your question @tejlmand. It's probably "that's what worked after a couple of hours struggling a to get cmake to give me my symbols" 🙃

[tejlmand]

I think this source is part of zephyr lib, @tejlmand. But I guess @oyvindronningstad could still answer, regardless of the change being already merged. :)

I took a second look.

Actually, you don't know which library the file will end up in.

At first glance, this looks reasonable, as it will be added to the currently defined library (usually not libzephyr.a)

zephyr/modules/trusted-firmware-m/CMakeLists.txt

Lines 208 to 210 in fed0352

	zephyr_library_sources_ifdef(CONFIG_BUILD_WITH_TFM interface/interface.c)
	# Non-Secure interface to request system reboot
	zephyr_library_sources_ifdef(CONFIG_TFM_PARTITION_PLATFORM src/reboot.c)

until one realizes there is NO zephyr_library() call in this CMakeLists.txt.
Because this is included as ZEPHYR_<MODULE>_CMAKE_DIR and zephyr is the current library, then you get the code in the zephyr lib, but if there had been another zephyr_library() call prior to this code in the parent scope, then the code would have ended up inside that particular library.

When adding sources to zephyr lib, then zephyr_sources should be used and not zephyr_library_sources.
Also, there should be a good reason for adding sources to zephyr lib, and not just then it works.
See this comment, on how zephyr lib may look:
#8825 (comment)

It's probably "that's what worked after a couple of hours struggling a to get cmake to give me my symbols" upside_down_face

Sound like a bad approach.