nx_emu_rv64.nx

nx_emu_rv64.nx -- sovereign RV64 interpreter (NX-EMU). Decodes + executes the RV64I + RV64M base needed to run nxc2-compiled RV64 programs over a flat guest address space, with a Linux RV64 syscall surface (exit/write/read). NO qemu -- the foreign emulator is demoted to a build-time differential ORACLE only. Replaces qemu for the non-native lanes (RV64/aarch64/arm32 on an x86_64 host). Guest memory model (per the grounded design): ONE flat mmap region; vaddr == offset (GUEST_BASE 0); pc is a guest vaddr fetched via g_ld; MAP_ANON zero-fill gives free .bss; loads/stores hit the same region; sp (x2) initialised by the loader. All guest pointers are translated (mem + va) before any host syscall. Decoded: lui(sign-ext) auipc | addi slti sltiu xori ori andi slli srli srai | add sub sll slt sltu xor srl sra or and | mul div divu rem remu (RV64M; div/rem edge cases per spec 13.2) | lb lh lw ld lbu lhu lwu | sb sh sw sd | beq bne blt bge bltu bgeu | jal jalr | ecall (exit 93/94, write 64, read 63). genealogy_id: riscv_unprivileged_isa_v20240411 + linux_riscv_abi lineage_id: nishi_nx_emu_rv64_m7 license_tier: ORIGINAL