Arm Toolchain for Embedded 

Sources:
* arm-toolchain: https://github.com/arm/arm-toolchain (commit 0bac08d50952133963671eeeb8c3e67695a32f49)
* picolibc: https://github.com/picolibc/picolibc.git (commit c0902a4b372c969be10204a9945c2480a395681b)
