Appendix A: Linux-specific ABI

This section of the RISC-V calling convention specification only applies to Linux-based systems.

In order to ensure compatibility between different implementations of the C library for Linux, we provide some extra definitions which only apply on those systems. These are noted in this section.

Linux-specific C type sizes and alignments

The following definitions apply for all ABIs defined in this document. Here there is no differentiation between ILP32 and LP64 ABIs.

Table 1. Linux-specific C type sizes and alignments
Type Size (Bytes) Alignment (Bytes)

wchar_t

4

4

wint_t

4

4

Linux-specific C type representations

The following definitions apply for all ABIs defined in this document. Here there is no differentiation between ILP32 and LP64 ABIs.

wchar_t is signed. wint_t is unsigned.