code wiki / _hdl_build / nx_paging_emit.nx
nx_paging_emit.nx
buildroot/runtime/_hdl_build/nx_paging_emit.nx
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nx_paging_emit.nx -- CPU-DATAPATH PAGING test (virtual-memory-paging-mmu, integration rung).
Table-computes a bare-metal rv64 image that proves the CPU TRANSPARENTLY translates virtual
addresses through the page table once satp.MODE=Sv39 -- no explicit walk, just a normal load:
1. lay a Sv39 gigapage PTE (0x20000007 = PPN 0x80000<<10 | V|R|W) at root[VPN2=3]=0x80008018
2. store a sentinel (0x5ECA1234) to PHYSICAL 0x80009000 (satp still Bare = identity)
3. build satp = (Sv39<<60) | root_PPN(0x80008) and csrrw it -> translation ON
4. LOAD from VIRTUAL 0xC0009000 -- the CPU walks the page table and reads PA 0x80009000
5. verify the loaded word == the sentinel -> emit "VOK" (else "X"); finisher.
"VOK" proves transparent CPU-datapath VA translation (the gigapage maps VA 0xC0000000.. -> PA
0x80000000.., so VA 0xC0009000 != its PA 0x80009000 -- a real translation, not identity).
Zero hand-written machine code: a tiny rv64 encoder + two-pass forward-branch resolution.
nx_paging_emit -> runtime/_hdl_build/_paging_virt.bin + .gold
Sovereign, no gcc/.sh. license_tier: ORIGINAL
dependencies 1 imports · 0 importers
imports: nx_syscalls.nx
imported by: nobody (leaf or entry point)
call flow from main pre-order; caps 40 nodes / depth 6 declared; ↻ = already shown
structs
| none |
consts
| 16 | const PE_MAGIC_8192: i64 = 8192 |
| 18 | const PE_OUT: *u8 = "runtime/_hdl_build/_paging_virt.bin" |
| 19 | const PE_GOLD: *u8 = "runtime/_hdl_build/_paging_virt.bin.gold" |
| 20 | const PE_LOG: *u8 = "knowledge/status/paging.log" |
| 22 | const PE_UART: i64 = 0x10000000 |
| 23 | const PE_FIN: i64 = 0x100000 |
| 24 | const PE_PASS: i64 = 0x5555 |
| 25 | const PE_MEM_BASE: i64 = 0x80000000 |
| 26 | const PE_CSR_SATP: i64 = 0x180 |
| 27 | const PE_CSR_MSTATUS: i64 = 0x300 |
| 28 | const PE_CSR_MEPC: i64 = 0x341 |
| 29 | const PE_MRET: i64 = 0x30200073 // mret instruction word |
| 30 | const PE_MPP_S: i64 = 0x800 // mstatus with MPP=01 (Supervisor) |
| 32 | const RV_X0: i64 = 0 |
| 33 | const RV_T0: i64 = 5 // UART |
| 34 | const RV_T1: i64 = 6 // value / satp |
| 35 | const RV_T2: i64 = 7 // mode scratch |
| 36 | const RV_T3: i64 = 28 // loaded |
| 37 | const RV_T4: i64 = 29 // expected |
| 38 | const RV_T5: i64 = 30 // base scratch |
| 40 | const PE_PTE_ADDR: i64 = 0x80008000 // root page table |
| 41 | const PE_PTE_OFF: i64 = 0x18 // root[VPN2=3] = +3*8 |
| 42 | const PE_PTE_VAL: i64 = 0x20000007 // gigapage PPN 0x80000, V|R|W |
| 43 | const PE_SENT_PA: i64 = 0x80009000 // sentinel physical address |
| 44 | const PE_SENT_VAL: i64 = 0x5ECA1234 |
| 45 | const PE_VA: i64 = 0xC0009000 // virtual address mapping -> PE_SENT_PA |
| 46 | const PE_SATP_PPN: i64 = 0x80008 // root >> 12 |
| 47 | const PE_SV39: i64 = 8 |
functions
| 49 | func pe_lui(rd: i64, imm20: i64) -> i64 { return ((imm20 & 0xFFFFF) << 12) | (rd << 7) | 0x37 } |
| 50 | func pe_addi(rd: i64, rs1: i64, imm: i64) -> i64 { return ((imm & 0xFFF) << 20) | (rs1 << 15) | (rd << 7) | 0x13 } |
| 51 | func pe_load(rd: i64, rs1: i64, f3: i64, imm: i64) -> i64 { return ((imm & 0xFFF) << 20) | (rs1 << 15) | (f3 << 12) | (rd << 7) | 0x03 } called by 1: pe_emit_image |
| 52 | func pe_store(rs2: i64, rs1: i64, f3: i64, imm: i64) -> i64 |
| 57 | func pe_branch(rs1: i64, rs2: i64, f3: i64, imm: i64) -> i64 called by 1: pe_emit_image |
| 64 | func pe_jal(rd: i64, imm: i64) -> i64 called by 1: pe_emit_image |
| 71 | func pe_slli(rd: i64, rs1: i64, shamt: i64) -> i64 { return ((shamt & 0x3f) << 20) | (rs1 << 15) | (1 << 12) | (rd << 7) | 0x13 } |
| 72 | func pe_srli(rd: i64, rs1: i64, shamt: i64) -> i64 { return ((shamt & 0x3f) << 20) | (rs1 << 15) | (5 << 12) | (rd << 7) | 0x13 } called by 1: pe_li32u |
| 73 | func pe_or(rd: i64, rs1: i64, rs2: i64) -> i64 { return (rs2 << 20) | (rs1 << 15) | (6 << 12) | (rd << 7) | 0x33 } called by 1: pe_emit_image |
| 74 | func pe_csrrw(rd: i64, csr: i64, rs1: i64) -> i64 { return ((csr & 0xfff) << 20) | (rs1 << 15) | (1 << 12) | (rd << 7) | 0x73 } called by 1: pe_emit_image |
| 76 | func pe_w32(buf: *u8, off: i64, w: i64) -> i64 |
| 82 | func pe_li32(buf: *u8, off: i64, rd: i64, val: i64) -> i64 |
| 91 | func pe_li32u(buf: *u8, off: i64, rd: i64, val: i64) -> i64 |
| 97 | func pe_emit_str(buf: *u8, off: i64, s: *u8, n: i64) -> i64 |
| 103 | func pe_p(s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(1,s,n); return 0 } |
| 104 | func pe_fn(fd: i64, v: i64) -> i64 { let bb: *u8=sys_mmap(28); var m: i64=v; if m<0{m=0-m}; let t: *u8=sys_mmap(28); var k: i64=0; if m==0{t[0]=48;k=1}; while m>0{t[k]=(48+(m%10)) as u8;m=m/10;k=k+1}; var i: i64=0; while i<k{bb[i]=t[k-1-i];i=i+1}; sys_write(fd,bb,k); return 0 } |
| 108 | func pe_emit_image(buf: *u8, fail_off: i64, halt_off: i64, pos_out: *i64, pte_val: i64, cont_off: i64) -> i64 |
| 154 | func pe_parse_num(s: *u8) -> i64 called by 1: main |
| 167 | func main(argc: i64, argv: *i64) -> i64 |