180 adaptation for avz support

[daniel-rossier]

This PR brings a new way to configure heap and stack size in SO3. Now, sizes are configured by means of Kconfig variables. It also fixes several potential issues with the previous hardcoded stack sizes in the linking script.
Furthermore, a lot of changes have been made at AVZ (hypervisor level) to get a more aligned version as it is used in the SOO framework.
All defconfig and its files have been cleaned up and adapted accordingly.

[AndreCostaaa]

If you want to go forward with the toolchain changes, I would maybe open a new PR, that simply adds the toolchain here
https://github.com/smartobjectoriented/so3/blob/main/docker/Dockerfile.env#L26-L29

Once we merge that PR, we can then rebase main here and make the CI go green

Additionally, all of the AVZ and SOO configs aren't tested by the CI, we already test virt_fb configs so we should also add those configs since there's gonna be a lot of changes in the upcoming months to that part of the codebase. Adding new SO3 configs should be as easy as adding new entries here:

so3/.github/workflows/build.yml

Lines 18 to 21 in c1bcc25

	CONFIG: ['virt32_fb_defconfig',
	'virt64_fb_defconfig',
	'virt32_lvperf_defconfig',
	]

Unless there are specific dependencies missing and in that case they also need to get added to the Dockerfile mentionned above. We could imagine getting rid of the dockerfile and instead have the CI install the necessary dependencies so that we can more easily go forward with these types of changes

Let me know what you think about those ideas

[AndreCostaaa]

So is the musl idea put on standby for now ?

I'm fine with changing it but please install it in the docker image env Dockerfile:

so3/docker/Dockerfile.env

Lines 26 to 29 in c1bcc25

	# Download aarch64-none-linux-gnu toolchain
	RUN wget https://armkeil.blob.core.windows.net/developer/Files/downloads/gnu-a/10.3-2021.07/binrel/gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu.tar.xz
	RUN tar -xvf gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu.tar.xz
	RUN rm gcc-arm-10.3-2021.07-x86_64-aarch64-none-linux-gnu.tar.xz

[daniel-rossier]

Well, this is for the kernel compilation, not for the user space. We have to keep the linux toolchain since it's used by the user space. We will migrate to a MUSL toolchain in the coming months.
Does it make sense?

[AndreCostaaa]

Yes it does, different toolchains for the kernel and user space. Sounds good to me
We still need to install it in the dockerfile though to make the CI pass

[AndreCostaaa]

I got a bit confused at first why here we're using CONFIG_MAX_THREADS while PROC_MAX_THREADS is used at line 205

Would you consider removing this define: #define PROC_MAX_THREADS CONFIG_MAX_THREADS and simply using CONFIG_MAX_THREADS throughout the code ? It would make the code easier to reason with

[daniel-rossier]

Yes, I agree. Even if the number_of_proc X CONFIG_MAX_THREADS will be incorrect since CONFIG_MAX_THREADS means the number of threads in the whole system.
In the future, we should consider to divide CONFIG_MAX_THREADS by the max. number of process which would be more accurate. Or should we implement this now?

[AndreCostaaa]

Can be done in another PR, we could remove that #define so that we use the same constant throughout the whole code. What do you think ?