; ======================================================================== ; ; (C) Copyright 2023 by Molly Rocket, Inc., All Rights Reserved. ; ; This software is provided 'as-is', without any express or implied ; warranty. In no event will the authors be held liable for any damages ; arising from the use of this software. ; ; Please see https://computerenhance.com for further information ; ; ======================================================================== ; ======================================================================== ; LISTING 42 ; ======================================================================== ; ; NOTE(casey): This is not meant to be a real compliance test for 8086 ; disassemblers. It's just a reasonable selection of opcodes and patterns ; to use as a first pass in making sure a disassembler handles a large ; cross-section of the encoding. To be absolutely certain you haven't ; missed something, you would need a more exhaustive listing! ; bits 16 mov si, bx mov dh, al mov cl, 12 mov ch, -12 mov cx, 12 mov cx, -12 mov dx, 3948 mov dx, -3948 mov al, [bx + si] mov bx, [bp + di] mov dx, [bp] mov ah, [bx + si + 4] mov al, [bx + si + 4999] mov [bx + di], cx mov [bp + si], cl mov [bp], ch mov ax, [bx + di - 37] mov [si - 300], cx mov dx, [bx - 32] mov [bp + di], byte 7 mov [di + 901], word 347 mov bp, [5] mov bx, [3458] mov ax, [2555] mov ax, [16] mov [2554], ax mov [15], ax push word [bp + si] push word [3000] push word [bx + di - 30] push cx push ax push dx push cs pop word [bp + si] pop word [3] pop word [bx + di - 3000] pop sp pop di pop si pop ds xchg ax, [bp - 1000] xchg [bx + 50], bp xchg ax, ax xchg ax, dx xchg ax, sp xchg ax, si xchg ax, di xchg cx, dx xchg si, cx xchg cl, ah in al, 200 in al, dx in ax, dx out 44, ax out dx, al xlat lea ax, [bx + di + 1420] lea bx, [bp - 50] lea sp, [bp - 1003] lea di, [bx + si - 7] lds ax, [bx + di + 1420] lds bx, [bp - 50] lds sp, [bp - 1003] lds di, [bx + si - 7] les ax, [bx + di + 1420] les bx, [bp - 50] les sp, [bp - 1003] les di, [bx + si - 7] lahf sahf pushf popf add cx, [bp] add dx, [bx + si] add [bp + di + 5000], ah add [bx], al add sp, 392 add si, 5 add ax, 1000 add ah, 30 add al, 9 add cx, bx add ch, al adc cx, [bp] adc dx, [bx + si] adc [bp + di + 5000], ah adc [bx], al adc sp, 392 adc si, 5 adc ax, 1000 adc ah, 30 adc al, 9 adc cx, bx adc ch, al inc ax inc cx inc dh inc al inc ah inc sp inc di inc byte [bp + 1002] inc word [bx + 39] inc byte [bx + si + 5] inc word [bp + di - 10044] inc word [9349] inc byte [bp] aaa daa sub cx, [bp] sub dx, [bx + si] sub [bp + di + 5000], ah sub [bx], al sub sp, 392 sub si, 5 sub ax, 1000 sub ah, 30 sub al, 9 sub cx, bx sub ch, al sbb cx, [bp] sbb dx, [bx + si] sbb [bp + di + 5000], ah sbb [bx], al sbb sp, 392 sbb si, 5 sbb ax, 1000 sbb ah, 30 sbb al, 9 sbb cx, bx sbb ch, al dec ax dec cx dec dh dec al dec ah dec sp dec di dec byte [bp + 1002] dec word [bx + 39] dec byte [bx + si + 5] dec word [bp + di - 10044] dec word [9349] dec byte [bp] neg ax neg cx neg dh neg al neg ah neg sp neg di neg byte [bp + 1002] neg word [bx + 39] neg byte [bx + si + 5] neg word [bp + di - 10044] neg word [9349] neg byte [bp] cmp bx, cx cmp dh, [bp + 390] cmp [bp + 2], si cmp bl, 20 cmp byte [bx], 34 cmp ax, 23909 aas das mul al mul cx mul word [bp] mul byte [bx + di + 500] imul ch imul dx imul byte [bx] imul word [9483] aam div bl div sp div byte [bx + si + 2990] div word [bp + di + 1000] idiv ax idiv si idiv byte [bp + si] idiv word [bx + 493] aad cbw cwd not ah not bl not sp not si not word [bp] not byte [bp + 9905] shl ah, 1 shr ax, 1 sar bx, 1 rol cx, 1 ror dh, 1 rcl sp, 1 rcr bp, 1 shl word [bp + 5], 1 shr byte [bx + si - 199], 1 sar byte [bx + di - 300], 1 rol word [bp], 1 ror word [4938], 1 rcl byte [3], 1 rcr word [bx], 1 shl ah, cl shr ax, cl sar bx, cl rol cx, cl ror dh, cl rcl sp, cl rcr bp, cl shl word [bp + 5], cl shr word [bx + si - 199], cl sar byte [bx + di - 300], cl rol byte [bp], cl ror byte [4938], cl rcl byte [3], cl rcr word [bx], cl and al, ah and ch, cl and bp, si and di, sp and al, 93 and ax, 20392 and [bp + si + 10], ch and [bx + di + 1000], dx and bx, [bp] and cx, [4384] and byte [bp - 39], 239 and word [bx + si - 4332], 10328 test bx, cx test dh, [bp + 390] test [bp + 2], si test bl, 20 test byte [bx], 34 test ax, 23909 or al, ah or ch, cl or bp, si or di, sp or al, 93 or ax, 20392 or [bp + si + 10], ch or [bx + di + 1000], dx or bx, [bp] or cx, [4384] or byte [bp - 39], 239 or word [bx + si - 4332], 10328 xor al, ah xor ch, cl xor bp, si xor di, sp xor al, 93 xor ax, 20392 xor [bp + si + 10], ch xor [bx + di + 1000], dx xor bx, [bp] xor cx, [4384] xor byte [bp - 39], 239 xor word [bx + si - 4332], 10328 rep movsb rep cmpsb rep scasb rep lodsb rep movsw rep cmpsw rep scasw rep lodsw ; NOTE(casey): Special thanks (as always!) to Mārtiņš Možeiko for figuring out why NASM ; wouldn't compile "rep stds" instructions. It was because it was a misprint in the 8086 ; manual! It was really just "rep stos", which of course is still in x64, and NASM ; assembles it just fine. rep stosb rep stosw call [39201] call [bp - 100] call sp call ax jmp ax jmp di jmp [12] jmp [4395] ret -7 ret 500 ret label: je label jl label jle label jb label jbe label jp label jo label js label jne label jnl label jg label jnb label ja label jnp label jno label jns label loop label loopz label loopnz label jcxz label int 13 int3 into iret clc cmc stc cld std cli sti hlt wait lock not byte [bp + 9905] lock xchg [100], al mov al, cs:[bx + si] mov bx, ds:[bp + di] mov dx, es:[bp] mov ah, ss:[bx + si + 4] and ss:[bp + si + 10], ch or ds:[bx + di + 1000], dx xor bx, es:[bp] cmp cx, es:[4384] test byte cs:[bp - 39], 239 sbb word cs:[bx + si - 4332], 10328 lock not byte CS:[bp + 9905] ; ; NOTE(casey): These were not in the original homework set, but have been added since, as people ; found instruction encodings that were not previously covered ; call 123:456 jmp 789:34 ; ; TODO(casey): I would like to uncomment this, but as far as I can tell, NASM doesn't recognize the ESC instruction :( ; so even if I just force the assembler to output the bits here, our disasm will fail to assemble because it will (correctly!) ; print the esc instruction and NASM will error because it doesn't know what that is. ; ; esc 938,ax ; ; ; TODO(casey): According to NASM, "rep movsb" is "not lockable". However the 8086 manual seems to think it is, and ; even describes what happens when you you lock a rep: the lock is held for the duration of the rep operation. So... ; yeah. Not sure why this doesn't work in NASM: ; ; lock rep movsb ;