ARM Trusted Firmware Coding Guidelines
https://github.com/ARM-software/arm-trusted-firmware/wiki/ARM-Trusted-Firmware-Coding-Guidelines
Procedure Call Standard for the ARM® Architecture
http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042f/IHI0042F_aapcs.pdf
Getting started with CMSIS
https://www.doulos.com/knowhow/arm/CMSIS/CMSIS_Doulos_Tutorial.pdf
Basics of the Cortex MCU Software Interface Standard: Part 1 - CMSIS Specification
https://www.embedded.com/design/programming-languages-and-tools/4438667/Basics-of-the-Cortex-MCU-Software-Interface-Standard--Part-1---CMSIS-Specification-
Guidelines for writing efficient C/C++ code
https://www.embedded.com/design/mcus-processors-and-socs/4006634/Guidelines-for-writing-efficient-C-C--code