# title
Differences between v1 and v2 of the ABI for the ARM Architecture

# topic.label
Differences between v1 and v2 of the ABI for the ARM Architecture

# metadata.contentDescription
This advisory note discusses a hitherto little noticed consequence of the ABI requirement for natural alignment for primitive data of size 1, 2, 4, and 8 bytes, and its implications for low level exception-handling code running on R profiles of version 7 of the Arm architecture and versions of the Arm architecture earlier than version 7, code that might be entered directly through an Armv7M exception vector, and tool chains that generate such code.