The new Arm GNU Toolchain is much bigger

[carlosperate]

It combines the cortex M and cortex A compilers into a single toolchain, so it will significantly increase the docker image size.

[carlosperate]

Based on the forum discussion:

• https://community.arm.com/support-forums/f/compilers-and-libraries-forum/53168/the-new-toolchain-is-too-bloated/178142#178142

Something we can do is remove the libraries for the platforms not relevant to micro:bit in arm-none-eabi/lib/thumb/ and lib/gcc/arm-none-eabi/11.3.1/thumb. We only need Cortex-M0+ and M4/M4f support, so we can leave the ARMv6-M and ARMv7E-M and remove the others (including v7ve+simd which is confusingly a Cortex-A one):

• https://en.wikipedia.org/wiki/ARM_Cortex-M#Instruction_sets

It should also be safe to remove arm-none-eabi/lib/arm/v5te and lib/gcc/arm-none-eabi/11.3.1/arm/v5te, but I'll have to double check:

• https://en.wikipedia.org/wiki/ARM_architecture_family#Cores

[carlosperate]

These should also be fine to be removed:

• share/doc
• share/gcc-arm-none-eabi/samples

[carlosperate]

The v12.3.1 is slimmer again, looks like they are stripping the symbols from the libraries again.
However, there are some issues building some of the micro:bit projects with this version:

• Issues with newer versions of arm GCC #3 (comment)