This series defines the UAPI for LoongArch32, marking my initial step towards upstreaming support for the architecture. Once the UAPI is ratified, we can proceed to scrutinise various kernel components to enable 32-bit support while simultaneously addressing user-space porting. Why am I upstreaming LoongArch32? ================================ Although 32-bit systems are experiencing declining adoption in general computing, LoongArch32 remains highly relevant within specific niches. Beyond embedded applications, several vendors are actively developing application-level LoongArch32 processors. Loongson, for example, has released two open-source reference hardware implementations: openLA500 and openLA1000 [6]. The architecture also holds considerable educational value, having been integrated into China's national computer architecture curricula and embedded systems courses. Additionally, the National Student Computer System Capability Challenge (NSCSCC) [1] features LoongArch32 CPUs, where hundreds of students design Linux-capable hardware implementations and compete on performance. This initiative has resulted in several exciting high-performance LoongArch32 cores, including LainCore[2], Wired[3], NOP-Core[4], NagiCore[5]....
