code wiki / _hdl_build / nx_emu_x86_rm16_test.nx
nx_emu_x86_rm16_test.nx
buildroot/runtime/_hdl_build/nx_emu_x86_rm16_test.nx
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nx_emu_x86_rm16_test.nx -- x86 full-system ladder R5 rung-3: 16-bit REAL-MODE decode.
The CPU boots in 16-bit real mode (operand size 16, NO REX prefix, different opcodes). This is a
minimal real-mode interpreter for the boot-stub subset:
B8+r iw mov r16, imm16 (B8=ax B9=cx BA=dx BB=bx ...)
89 /r mov r/m16, r16 (mod=11 reg-reg)
01 /r add r/m16, r16 (16-bit wrap)
F4 hlt (stop)
KAT: a real-mode stub computes ax = 40 + 2 = 42 then hlts. HONEST SCOPE: this minimal subset;
the full real-mode ISA + segment:offset addressing + the far-jump that flushes into protected mode
= further R5 work (then R6 paging, R7 devices, R8 kernel boot). No hardware writes (Rule 26).
expect_exit: 0 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
| none |
functions
| 14 | func r16_b(c: *u8, o: i64, b: i64) -> i64 { c[o]=(b & 0xff) as u8; return o+1 } called by 1: main |
| 15 | func r16_iw(c: *u8, o: i64, v: i64) -> i64 { c[o]=(v&0xff) as u8; c[o+1]=((v>>8)&0xff) as u8; return o+2 } called by 1: main |
| 16 | func r16_puts(s: *u8) -> i64 { var n: i64=0; while s[n]!=(0 as u8){n=n+1} sys_write(1,s,n); return 0 } |
| 17 | func r16_num(v: i64) -> i64 { let b: *u8=sys_mmap(28); var m: i64=v; if m<0{m=0-m;sys_write(1,"-" as *u8,1)} let t: *u8=sys_mmap(28); var k: i64=0; if m==0{t[0]=48 as u8;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{b[i]=t[k-1-i];i=i+1} sys_write(1,b,k); return 0 } |
| 20 | func emu_x86_run_16(code: *u8, len: i64, reg16: *i64) -> i64 called by 1: main |
| 34 | func main() -> i64 |