nx_argv.nx

nx_argv.nx -- Linux RV64 entry-stack builder. At program entry the Linux kernel hands the runtime a stack laid out per System V ABI: sp -> argc (i64) argv[0] (pointer to NUL-terminated string) argv[1] ... argv[argc-1] NULL envp[0] envp[1] ... envp[K-1] NULL auxv entries (Elf64_auxv_t = i64 a_type, i64 a_un.a_val) AT_NULL terminator (a_type=0, a_un=0) (string area: argv/envp string bodies) Without this layout, a simulated program crashes the moment it reads its first argument. Setting it up correctly lets us pass arguments through nxc_native_wrap to the simulated program, which is required for any meaningful test harness. Pairs with nx_rv64_sim (consumes the stack via sp register) + nxc_native_wrap (wires this in front of nx_rv64_run). Reference: System V ABI for RV64, "Process Initialization" section (https://github.com/riscv-non-isa/riscv-elf-psabi-doc).