nx_aarch64.nx

nx_aarch64.nx -- AArch64 Linux AAPCS asm emitter (foundation; session 1). Pure NishiLang port of nxc2/aarch64.c. Lives outside the C side per cardinal feedback-no-nxc2-c-extension-only-nishilang-forward. This file is the FOUNDATION layer; sessions 2-N fill in the per-opcode IR-to-asm dispatch and wire into nxc.nx as --target aarch64. Session 1 scope (this file): * AArch64 register name table (AAPCS) * function prologue / epilogue (stp x29,x30 / add x29,sp / sub sp) * .text / .rodata section directives * label emission * literal constant load (movz + movk chain for full 64-bit imm) * register-to-register move (mov xD, xS) * PIC-aware address load (adrp + add for label) * add / sub register-to-register (add xD, xS, xN / sub) * syscall (svc #0 -- the ARM64 supervisor call) * .asciz string literal emission with byte-escape Sessions 2-N (deferred): * IR-instruction dispatch (binop / cmp / branch / call / load / store / GEP / phi / return / tail_call / inline_asm) * stack-machine slot layout per nxc2/aarch64.c * regalloc integration (linear-scan with AAPCS-preserved regs) * NEON SIMD (mov vD.16b, vS.16b / add vD.4s, vS.4s, vN.4s) * full nxc.nx wiring as --target aarch64 dispatch Output format: GNU AS unified syntax (no AT&T % prefix), Linux AAPCS ABI, position-independent via adrp/add for label refs. Byte-compatible with `aarch64-linux-gnu-as`. genealogy_id: nxc2_aarch64_c_2026 + aapcs64_v1 lineage_id: nx_aarch64_foundation_v1 nx_safety_envelope: intended_use: "Foundation emit library for AArch64 Linux AAPCS assembly text. Per-primitive functions writing a shared OutBuf. Session 1 of N for the full IR-driven backend. Required for the hardware-agnostic self-host (M0d / M2 kernel