`nx_smoke_sim.nx` source

1// nx_smoke_sim.nx -- end-to-end smoke test of the off-C run-loop.
2//
3// Hand-builds a minimal RV64 Linux ELF that exits with code 42,
4// loads it via nx_loader, runs it via nx_rv64_sim, asserts the
5// exit code matches.  Proves the OFF-C verification path works
6// without docker / qemu.
7//
8// This is the smallest possible end-to-end demonstration of the
9// sovereign run-loop:
10//
11//   1. Bytes shaped like an ELF -> nx_loader places PT_LOAD
12//      segment at vaddr 0x10000.
13//   2. Entry pc = 0x10000 + 120; PC walks 3 instructions:
14//        addi a0, zero, 42   -- a0 = 42
15//        addi a7, zero, 93   -- a7 = sys_exit
16//        ecall               -- syscall(93, 42, ...)
17//   3. nx_rv64_sim's syscall handler sees nr=93, halts cpu,
18//      records exit_code = 42.
19//   4. We assert cpu.halted=1 + cpu.exit_code=42.
20//
21// Run: produces a 0 exit code on success, non-zero on any failure.
22//
23// Pairs with bootstrap_native.sh as the proof-of-concept that the
24// in-NishiLang sim is a viable qemu replacement.
25
26// nx_safety_envelope:
27//   intended_use:       AUTO_APPLIED -- primitive-specific tuning queued
28//   sil_target:         SIL1
29//   evidence:           [bulk_applied_2026-05-16, see-file-comment-for-detail]
30//   verdict:            NOT_YET_EVALUATED
31
32import "syscalls.nx"
33import "nx_loader.nx"
34import "nx_rv64_sim.nx"
35
36// Build the same ELF that nx_loader's self-test does, then run it.
37func main() -> i64 {
38    // Construct a minimal ELF in memory:
39    //   header (64) + 1 program header (56) + 12 bytes of code
40    //   total = 132 bytes; vaddr = 0x10000; entry = 0x10000 + 120
41    let elf: *u8 = sys_mmap(256)
42    var i: i64 = 0
43    while i < 256 { elf[i] = 0; i = i + 1 }
44
45    elf[0] = 0x7F; elf[1] = 0x45; elf[2] = 0x4C; elf[3] = 0x46
46    elf[4] = 2; elf[5] = 1; elf[6] = 1
47    elf[16] = 2     // ET_EXEC
48    elf[18] = 0xF3  // EM_RISCV
49    elf[24] = 0x78; elf[25] = 0x00; elf[26] = 0x01; elf[27] = 0x00  // entry = 0x10078
50    elf[32] = 64    // phoff
51    elf[52] = 64    // ehsize
52    elf[54] = 56    // phentsize
53    elf[56] = 1     // phnum
54
55    // Program header at offset 64.
56    elf[64] = 1     // PT_LOAD
57    elf[68] = 5     // R|X
58    elf[72] = 120   // p_offset
59    elf[80] = 0x00; elf[81] = 0x00; elf[82] = 0x01; elf[83] = 0x00  // p_vaddr = 0x10000
60    elf[96] = 12    // p_filesz
61    elf[104] = 12   // p_memsz
62
63    // Code: addi a0, zero, 42 ; addi a7, zero, 93 ; ecall
64    elf[120] = 0x13; elf[121] = 0x05; elf[122] = 0xA0; elf[123] = 0x02
65    elf[124] = 0x93; elf[125] = 0x08; elf[126] = 0xD0; elf[127] = 0x05
66    elf[128] = 0x73; elf[129] = 0x00; elf[130] = 0x00; elf[131] = 0x00
67
68    // Allocate a 1 MB sim memory and load the segment.
69    let mem: *u8 = sys_mmap(0x20000)
70    let entry: i64 = nx_loader_load(elf, 132, mem, 0x20000)
71    if entry != 0x10078 {
72        sys_write(2, "smoke: load failed\n" as *u8, 19)
73        return 1
74    }
75
76    // Spin up CPU + run.
77    let cpu: *NxRv64Cpu = nx_rv64_cpu_new(mem, 0x20000, entry)
78    nx_rv64_cpu_set_sp(cpu, 0x20000 - 64)
79    let r: i64 = nx_rv64_run(cpu, 1000)
80    if r != 0 {
81        sys_write(2, "smoke: run failed\n" as *u8, 18)
82        return 2
83    }
84    if cpu.halted != 1 {
85        sys_write(2, "smoke: not halted\n" as *u8, 18)
86        return 3
87    }
88    if cpu.exit_code != 42 {
89        sys_write(2, "smoke: wrong exit code\n" as *u8, 23)
90        return 4
91    }
92
93    // Success: verifies that on this host, the in-NishiLang
94    // simulator can run a complete RV64 ELF end-to-end.
95    sys_write(2, "smoke: off-C run-loop OK -- exit=42 as expected\n" as *u8, 48)
96    return 0
97}
nx_smoke_sim.nx source

`nx_smoke_sim.nx` source
