⚡ Reduce code binary size

[ion098]

Summary:

This PR reduces the memory footprint of PROS projects; it does this by reducing code size through the usage of Thumb mode, as well as removing unneeded linker sections.

Motivation:

Reducing memory footprint means smaller upload times.

Test Plan:

• Check it compiles
• Check that the kernel runs fine

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

https://artprodcus3.artifacts.visualstudio.com/A268c8aad-3bb0-47d2-9a57-cf06a843d2e8/a421d041-2579-4bf8-a0aa-d7a0307dade3/_apis/artifact/cGlwZWxpbmVhcnRpZmFjdDovL3B1cmR1ZS1hY20tc2lnYm90cy9wcm9qZWN0SWQvYTQyMWQwNDEtMjU3OS00YmY4LWEwYWEtZDdhMDMwN2RhZGUzL2J1aWxkSWQvNjUyNy9hcnRpZmFjdE5hbWUvdGVtcGxhdGU1/content?format=zip

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[djava]

Explanation for these changes please? I'm unclear on why you're making like, any of them.

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

/azp run

[azure-pipelines]

Pull request contains merge conflicts.

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

https://artprodcus3.artifacts.visualstudio.com/A268c8aad-3bb0-47d2-9a57-cf06a843d2e8/a421d041-2579-4bf8-a0aa-d7a0307dade3/_apis/artifact/cGlwZWxpbmVhcnRpZmFjdDovL3B1cmR1ZS1hY20tc2lnYm90cy9wcm9qZWN0SWQvYTQyMWQwNDEtMjU3OS00YmY4LWEwYWEtZDdhMDMwN2RhZGUzL2J1aWxkSWQvNjU0My9hcnRpZmFjdE5hbWUvdGVtcGxhdGU1/content?format=zip

[SizzinSeal]

tested, works

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

Download link

[SizzinSeal]

this works, tests successful

[SizzinSeal]

Here is the size difference of the cold package when using -mthumb-interwork and not:

with -mthumb-interwork 1,326,332 bytes
without -mthumb-interwork 1,326,332 bytes

They are exactly the same size. This indicates that -mthumb-interwork has no effect on the size of the cold package.
This is supported by the GCC docs:

-mthumb-interwork
Generate code that supports calling between the ARM and Thumb instruction sets. Without this option, on pre-v5 architectures, the two instruction sets cannot be reliably used inside one program. The default is -mno-thumb-interwork, since slightly larger code is generated when -mthumb-interwork is specified. In AAPCS configurations this option is meaningless.

There are 2 points in the text that support this:

In AAPCS configurations this option is meaningless

PROS uses an AAPCS configuration

Without this option, on pre-v5 architectures, the two instruction sets cannot be reliably used inside one program

The Cortex A9 in the brain uses the "arm-v7" architecture, which is not a "pre-v5" architecture, implying that this option is not needed.

Since it has been shown PROS works without issue without the -mthumb-interwork flag, and is supported by GCC documentation and testing, the -mthumb-interwork flag should not be added back.

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Rocky14683]

Download link

[SizzinSeal]

@ion098 is this ready to be merged?

[ion098]

@SizzinSeal Yes, this is ready to be merged now.

[SizzinSeal]

@Rocky14683 the download link is invalid

[Rocky14683]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).