_ubit_gate.nx

buildroot/runtime/_hdl_build/_ubit_gate.nx

5761 B103 linesdepth 2pulls 2 transitivereach 0 importersview sourcekind gate/proof

docs dependencies structs consts functions

about

_ubit_gate.nx -- LOCK for Sv39 USER/SUPERVISOR page isolation (U-bit + mstatus.SUM, X-PAGE-UBIT-001). Proves the CPU enforces the U-bit per privilege (riscv-priv-spec): an S-mode access to a USER page is DENIED unless mstatus.SUM; a supervisor page is always S-accessible. Drives nx_ubit_emit (data-PTE + mstatus-extra args) on the sovereign emu with SINGLE-AXIS controls so each rule is proven distinctly: T1 S + U-page + SUM : data 0x2000001F (U=1), mstatus +SUM(0x40000) -> access ALLOWED -> "UOK" T2 S + U-page + no-SUM: data 0x2000001F (U=1), mstatus +0 -> DENIED -> load-page-fault -> "UPF" T3 S + sup-page+ no-SUM: data 0x2000000F (U=0), mstatus +0 -> ALLOWED (supervisor page) -> "UOK" T1 vs T2 differ ONLY in SUM -> proves SUM gating. T2 vs T3 differ ONLY in the U bit -> proves the U-bit. GREEN only if T1..T3 hold. Evidence -> knowledge/status/priv.log (UBITGATE). 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

12	const UB_EMIT: *u8 = "_offc/nx_ubit_emit.elf"
13	const UB_SOV: *u8 = "_offc/nx_boot_run_sov.elf"

functions

15	func g_p(s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(1,s,n); return 0 } called by 2: g_row main calls 1: sys_write
16	func g_fp(fd: i64, s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(fd,s,n); return 0 } called by 1: main calls 1: sys_write
17	func g_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 } called by 1: main calls 2: sys_mmap sys_write
20	func g_run(prog: u8, a1: u8, a2: u8, a3: u8, outpath: *u8) -> i64 called by 1: g_case calls 7: sys_fork sys_openat_wr sys_dup3 sys_mmap sys_execve sys_exit+1
40	func g_read(path: u8, buf: u8, cap: i64) -> i64 called by 1: g_case calls 3: sys_openat_rd sys_read sys_close
49	func g_has(buf: u8, n: i64, pat: u8, pl: i64) -> i64 called by 1: main
56	func g_case(data_pte: u8, mstatus: u8, binp: u8, txt: u8, buf: *u8) -> i64 called by 1: main calls 2: g_run g_read
61	func g_row(name: u8, pass: i64) -> i64 { g_p(" " as u8); g_p(name); if pass==1 { g_p(" PASS\n" as u8) } else { g_p(" FAIL\n" as u8) } return 0 } called by 1: main calls 1: g_p
63	func main() -> i64 calls 11: sys_mmap g_case g_has g_p g_row sys_openat_append+5