ABI extensions (if necessary)

An Application Binary Interface (ABI) is a specification that defines how different software components should interact at a binary level. It's a contract between program modules that defines how to use the interface correctly. It specifies things like how function calls should be made, how data should be laid out in memory, and how system calls should be invoked.

ABI extensions refer to the additions or modifications to an existing ABI to support new features or behaviors. This might be necessary when you're introducing a new ISA or making significant changes to an existing one. For example, if your new ISA has new types of registers or new instructions, you might need to extend the ABI to account for these.

The extensions could involve:

• Calling Conventions: If the new ISA has new registers or changes how existing registers are used, you might need to change the calling convention, which is the part of the ABI that defines how functions' arguments and return values are passed.

• Data Layout: If the new ISA introduces new data types, or changes the alignment or padding requirements of existing types, you might need to update the rules for laying out data in memory.

• System Calls: If the new ISA changes how system calls are made, you'll need to reflect this in the ABI.

• Binary Formats: If the new ISA requires changes to the format of executable or object files, this will also be part of the ABI.