resume working; import awk-based assembler
This commit is contained in:
parent
e48ae306ba
commit
77b1ad7cef
72
Makefile
72
Makefile
@ -1,80 +1,42 @@
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PROGRAMS = hello.com sys.com
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KERNEL = @rdos.com
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DISTFILES = $(KERNEL) $(PROGRAMS)
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VERSION = $(shell git log -1 --format=%cd --date=format:%Y%m%d)
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PRODUCT = rdos
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VERSION = $(shell git log -1 --format=%cd --date=format:%Y%m%d)
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QEMU = qemu-system-i386
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QEMU_ARGS += $(shell test -w /dev/kvm && echo --enable-kvm)
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METRIC = stat -c '%8s %n'
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PROGRAMS = hello.com sys.com
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KERNEL = @$(PRODUCT).com
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DISTFILES = $(KERNEL) $(PROGRAMS)
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FLOPPY = 1440
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# Programs used for building
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NASM = nasm
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NASM_ARGS = -s -Isrc --before "cpu 8086" -DPRODUCT=$(PRODUCT) -DVERSION=$(VERSION)
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NASM_ARGS = -s --before "cpu 8086" -DPRODUCT=$(PRODUCT) -DVERSION=$(VERSION)
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AS = host/as
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SYS = ./sys.elf
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ifndef DISPLAY
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QEMU_ARGS += --display curses
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endif
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SYS = host/sys.elf
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.PHONY: default clean qemu-floppy5 qemu-floppy3
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.PHONY: default clean qemu
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.PRECIOUS: %.com
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default: fd1440.img
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default: fd$(FLOPPY).img
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# Host utils
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host/%.elf: host/%.c
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%.elf: host/%.c
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$(CC) -o $@ $<
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# COM programs
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%.com: src/%.asm src/*.inc
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$(NASM) $(NASM_ARGS) -l $(@:.com=.lst) -o $@ $<
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$(METRIC) $@
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$(NASM) $(NASM_ARGS) -Isrc -l $(@:.com=.lst) -o $@ $<
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%.hex: src/%.asm src/*.inc
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$(NASM) $(NASM_ARGS) -f ith -l $(@:.hex=.lst) -o $@ $<
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# Bootloaders, first sector on partition
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# Bootloader images
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%.bs: boot/%.asm
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$(NASM) $(NASM_ARGS) -o $@ $<
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# Special case: variations of FAT vbr
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fat1.bs: boot/fat.asm
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$(NASM) $(NASM_ARGS) -DFAT12 -DCHS -o $@ $<
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fat4.bs: boot/fat.asm
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$(NASM) $(NASM_ARGS) -DFAT16 -DCHS -o $@ $<
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fat6.bs: boot/fat.asm
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$(NASM) $(NASM_ARGS) -DFAT16 -DCHS -DLARGE -o $@ $<
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$(AS) $@ $<
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fd%.img: $(DISTFILES) $(SYS)
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mformat -C -i $@ -f $* -v "$(PRODUCT) $(VERSION)" ::
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mcopy -i $@ $(DISTFILES) ::
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$(SYS) $@ $(KERNEL)
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hdd.img: mbr.bs $(KERNEL) fd1440.img
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dd if=mbr.bs bs=512 count=1 of=$@
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dd if=$(KERNEL) bs=512 seek=1 of=$@
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dd if=fd1440.img bs=512 seek=63 of=$@
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clean:
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rm -f *.com *.bs *.0 *.lst *.img *.bin *.hex
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rm -f host/*.elf
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qemu-floppy3: fd1440.img
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$(QEMU) $(QEMU_ARGS) -boot a -fda fd1440.img
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qemu-floppy5: fd360.img
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$(QEMU) $(QEMU_ARGS) -boot a -fda fd360.img
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qemu-hdd: hdd.img
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$(QEMU) $(QEMU_ARGS) -boot c -hda hdd.img
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dosbox-%: %.com fd1440.img
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dosbox -c "mount P $(CURDIR)" -c P: -c "IMGMOUNT A: FD1440.IMG -t floppy" -c "$< $(ARGS)" -c pause -c exit
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emu2-%: %.com
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emu2 $< $(ARGS)
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qemu: fd$(FLOPPY).img
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qemu-system-i386 $(shell test -w /dev/kvm && echo --enable-kvm) $(shell test -n "$DISPLAY" || echo --display curses) -boot a -drive file=fd$(FLOPPY).img,format=raw,index=0,if=floppy
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8
boot/hello.asm
Normal file
8
boot/hello.asm
Normal file
@ -0,0 +1,8 @@
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org 0x7C00
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jmp short main
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nop
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nop
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main mov ax, 0x0e37
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int 0x10
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halt hlt
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jmp short halt
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4
host/as
Executable file
4
host/as
Executable file
@ -0,0 +1,4 @@
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#!/bin/sh
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outfile="$1"
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infile="$2"
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( awk -f host/asm.awk -v of=sym <"$infile"; cat "$infile") | awk -f host/asm.awk -v of=lst
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422
host/asm.awk
Normal file
422
host/asm.awk
Normal file
@ -0,0 +1,422 @@
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#!/usr/bin/awk -f
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BEGIN {
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if (!of) of="lst"
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pos=0
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errors=0
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# lookup table for ord()
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for (i = 32; i <= 128; i++) {
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t=sprintf("%c", i)
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_ord_[t]=i
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}
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# 8-bit general purpose registers
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r8["al"]=0
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r8["cl"]=1
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r8["dl"]=2
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r8["bl"]=3
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r8["ah"]=4
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r8["ch"]=5
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r8["dh"]=6
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r8["bh"]=7
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# 16-bit general purpose registers
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r16["ax"]=0
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r16["cx"]=1
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r16["dx"]=2
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r16["bx"]=3
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r16["sp"]=4
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r16["bp"]=5
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r16["si"]=6
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r16["di"]=7
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# segment registers
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sreg["es"]=0
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sreg["cs"]=1
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sreg["ss"]=2
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sreg["ds"]=3
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# indirect access register combinations
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modstr["bxsi"]=0
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modstr["sibx"]=0
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modstr["bxdi"]=1
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modstr["dibx"]=1
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modstr["bpsi"]=2
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modstr["sibp"]=2
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modstr["bpdi"]=3
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modstr["dibp"]=3
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modstr["si"]=4
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modstr["di"]=5
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modstr["bx"]=7
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# ALU operations
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alu["add"]=0
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alu["or"]=1
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alu["adc"]=2
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alu["sbb"]=3
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alu["and"]=4
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alu["sub"]=5
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alu["xor"]=6
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alu["cmp"]=7
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# near conditional jumps
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ops_rel8["jo"]=112+0
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ops_rel8["jno"]=112+1
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ops_rel8["jb"]=112+2
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ops_rel8["jc"]=112+2
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ops_rel8["jnae"]=112+2
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ops_rel8["jae"]=112+3
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ops_rel8["jnb"]=112+3
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ops_rel8["jnc"]=112+3
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ops_rel8["je"]=112+4
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ops_rel8["jz"]=112+4
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ops_rel8["jne"]=112+5
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ops_rel8["jnz"]=112+5
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ops_rel8["jbe"]=112+6
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ops_rel8["jna"]=112+6
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ops_rel8["ja"]=112+7
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ops_rel8["jnbe"]=112+7
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ops_rel8["js"]=112+8
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ops_rel8["jns"]=112+9
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ops_rel8["jp"]=112+10
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ops_rel8["jpe"]=112+10
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ops_rel8["jnp"]=112+11
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ops_rel8["jpo"]=112+11
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ops_rel8["jl"]=112+12
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ops_rel8["jnge"]=112+12
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ops_rel8["jge"]=112+13
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ops_rel8["jbl"]=112+13
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ops_rel8["jle"]=112+14
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ops_rel8["jng"]=112+14
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ops_rel8["jg"]=112+15
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ops_rel8["jnle"]=112+15
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# single-byte opcodes without operands
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ops_sb["nop"]=128+16
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ops_sb["stosb"]=170
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ops_sb["stosw"]=171
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ops_sb["lodsb"]=172
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ops_sb["lodsw"]=173
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ops_sb["ret"]=195
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ops_sb["retf"]=203
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ops_sb["hlt"]=244
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}
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# error string to insert into listing
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function err(str) {
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errors++
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if (of=="lst") printf("**** %s\n", str)
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}
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# submit a assembling result to output
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# set label of current line to off
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function submit(off) {
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if (of=="lst") printf("%04X %-18s %s\n", off, hex, $0)
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if (of=="hex" && hex) printf("%s", hex)
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if (label) {
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if (of=="sym") printf("%s\tsym\t%d\n", label, off)
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if (label in prevsym && prevsym[label]!=off) {
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err("label " label " different during second pass, was " prevsym[label] ", now " off)
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}
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sym[label]=off
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}
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pos=pos+length(hex)/2
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hex=""
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}
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# gets a symbol's values
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function getsym(name) {
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if (substr(name,1,1)=="0" || int(name)) {
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return int(name)
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}
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if (substr(name,1,1)==".") name = plabel name
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if (name in prevsym) {
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return prevsym[name]
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} else if (name in sym) {
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return sym[name]
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}
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return 0
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}
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# encode a signed byte
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function pushb(val) {
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#print("; pushb " val)
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if (val<0 || val>=256) err("Value " val " does not fit in byte")
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hex=hex sprintf("%02X",val)
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}
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# encode a signed byte (for rel8)
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function pushsb(val) {
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while (val < 0) val = val + 256
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pushb(val)
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}
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# encode a word
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function pushw(val) {
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while (val<0) val=val+65536
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t=sprintf("%04X",val)
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hex=hex substr(t,3) substr(t,1,2)
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}
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# encode a modrm byte
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function modrm(str, spare, rs) {
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mod=3
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rm=0
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if (str in rs) {
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mod=3
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rm=rs[str]
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} else if (substr(str,1,1)=="[") {
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rmap=""
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gsub(/^\[|\]$/, "", str)
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split(str,rmp,"+")
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disp=0
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for (i in rmp) {
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if (rmp[i] in r16) {
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rmap=rmap rmp[i]
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} else {
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disp = disp + getsym(rmp[i])
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mod=2
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}
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}
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if (!rmap) {
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mod=0
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rm=6
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} else if (rmap in modstr) {
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rm=modstr[rmap]
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} else {
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err("Bad modR/M")
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}
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}
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#print("; modR/M:", mod, spare, rm)
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pushb(mod*64+spare*8+rm)
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if (mod == 1) {
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pushb(disp)
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} else if (mod == 2 || (mod == 0 && rm == 6)) {
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pushw(disp)
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}
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}
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# common encoding: two operands, one is modrm, other in spare field
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# last two bits of opcode specify width (byte/word) and whether modrm operand is first or second
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function enc(opcode) {
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}
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# common encoding: one operand encoded as modrm with fixed spare field
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# operand can be byte or word, encoded in last bit of opcode
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function encfs(opcode, spare) {
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if (wordop) {
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pushb(opcode)
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modrm(op1, spare, r16)
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} else if (byteop) {
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pushb(opcode)
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modrm(op1, spare, r8)
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}
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}
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# dont process empty lines or comment lines
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/^( |\t)*(;|%)/ || /^( |\t)*$/ {
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if (of=="lst") printf("%24s%s\n","",$0)
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next
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}
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# load symbols from previous pass
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$2=="sym" {
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prevsym[$1]=int($3)
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#printf("; %s (%s=%X)\n", $0,$1,prevsym[$1])
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next
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}
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# Start parsing the line
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# and set up per-line vars
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{
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label=$1
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gsub(/:$/, "",label)
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opn=2
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split("", b, ":")
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byteop=1
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wordop=1
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dwordop=1
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}
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# no label on line! fixup
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/^ / || /^\t/ {
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label=""
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opn=1
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}
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{
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# implement local labels
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if (substr(label,1,1)==".") {
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label=plabel label
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} else if (label) {
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plabel=label
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}
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# take note if we got a instruction size specifier
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op=$(opn)
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if($(opn+1)=="byte" || $(opn+1)=="short") {
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wordop=0
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dwordop=0
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opn++
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} else if ($(opn+1)=="word" || $(opn+1)=="near") {
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byteop=0
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dwordop=0
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opn++
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} else if ($(opn+1)=="dword" || $(opn+1)=="far") {
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byteop=0
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wordop=0
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opn++
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}
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split("", a, ":")
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c=0
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for (i=opn+1;i<=NF;i++) {
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if (substr($(i),1,1)==";") break
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a[++c]=$(i)
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if (substr($(i),1,1)=="\"") {
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do {
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i++
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j=index($(i), "\"")
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if (j) {
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a[c]=a[c] " " substr($(i), 1, j)
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break
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} else {
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a[c]=a[c] " " $(i)
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}
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} while($(i))
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} else {
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gsub(/,$/, "", a[c])
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}
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}
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op1=a[1]
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op2=a[2]
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# pre-estimate if operand could be encoded as modrm
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rm1=(op1 in r16) || (op1 in r8) || substr(op1,1,1)=="["
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rm2=(op2 in r16) || (op2 in r8) || substr(op2,1,1)=="["
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# if byte register in operands, it cant be a word or dword operation
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if (op1 in r8 || op2 in r8) {
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wordop=0
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dwordop=0
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}
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# if word register in operands, it cant be a byte or dword operation
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if (op1 in r16 || op2 in r16 || op2 in sreg) {
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byteop=0
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dwordop=0
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}
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}
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# the source line is parsed by here:
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# - op: opcode name
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# - a: array of operands, starting with 1
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# - c: number of operands
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# - byteop, wordop, dwordop: test before encoding, all 1 per default
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# pseudo-opcodes
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op=="cpu" {
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next
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}
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op=="org" {
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pos=getsym(a[1])
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submit(pos);next
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}
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op=="equ" {
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val=getsym(a[1])
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submit(val);next
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}
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op=="db" {
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for(i=1;i<=c;i++) {
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if (substr(a[i],1,1)=="\"") {
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for(j=2;j<length(a[i]);j++) {
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pushb(_ord_[substr(a[i],j,1)])
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}
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} else pushb(getsym(a[i]))
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}
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}
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op=="dw" {
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for(i=1;i<=c;i++) pushw(getsym(a[i]))
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}
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# arithmetics: ADD, SUB, XOR etc
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op in alu {
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# modrm <- reg
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if (rm1 && op2 in r8) {
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pushb(0+alu[op]*8)
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modrm(op1, r8[op2], r8)
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} else if (rm1 && op2 in r16) {
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pushb(1+alu[op]*8)
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modrm(op1, r16[op2], r16)
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# reg <- modrm
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} else if (op1 in r8 && rm2) {
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pushb(2+alu[op]*8)
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modrm(op2, r8[op1], r8)
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} else if (op1 in r16 && rm2) {
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pushb(3+alu[op]*8)
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modrm(op2, r16[op1], r16)
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# modrm <- imm
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} else if (byteop && rm1 || op1 in r8) {
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pushb(128) # 80
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modrm(op1, alu[op], r8)
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pushb(getsym(op2))
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} else if (wordop && rm1 || op1 in r16) {
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pushb(129) # 81
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modrm(op1, alu[op], r16)
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pushw(getsym(op2))
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}
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}
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# MOV variants
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op=="mov" {
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# modrm <-> reg
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if (rm1 && op2 in r8) {
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pushb(136) # 88
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modrm(op1, r8[op2], r8)
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} else if (rm1 && op2 in r16) {
|
||||
pushb(137) # 89
|
||||
modrm(op1, r16[op2], r16)
|
||||
} else if (op1 in r8 && rm2) {
|
||||
pushb(138)
|
||||
modrm(op2, r8[op1], r8)
|
||||
} else if (op1 in r16 && rm2) {
|
||||
pushb(139)
|
||||
modrm(op2, r16[op1], r16)
|
||||
# modrm <-> sreg
|
||||
} else if (rm1 && op2 in sreg) {
|
||||
pushb(140)
|
||||
modrm(op1, sreg[op2], r16)
|
||||
} else if (rm2 && op1 in sreg) {
|
||||
pushb(142)
|
||||
modrm(op2, sreg[op1], r16)
|
||||
# reg <- imm
|
||||
} else if (op1 in r8) {
|
||||
pushb(176+r8[op1])
|
||||
pushb(getsym(op2))
|
||||
} else if (op1 in r16) {
|
||||
pushb(184+r16[op1])
|
||||
pushw(getsym(op2))
|
||||
# modrm <- imm
|
||||
} else if (byteop && rm1) {
|
||||
pushb(198)
|
||||
modrm(rm1, 0, r16)
|
||||
} else if (wordop && rm1) {
|
||||
pushb(199)
|
||||
modrm(rm1, 0, r16)
|
||||
}
|
||||
}
|
||||
op=="push" && op1 in r16 {
|
||||
pushb(80+r16[op1])
|
||||
}
|
||||
op=="pop" && op1 in r16 {
|
||||
pushb(88+r16[op1])
|
||||
}
|
||||
op=="test" && op2 in r8 { # 84
|
||||
pushb(132)
|
||||
modrm(op1, r8[op2], r8)
|
||||
}
|
||||
op=="int" { # CD
|
||||
pushb(205)
|
||||
pushb(getsym(op1))
|
||||
}
|
||||
op=="jmp" && byteop {
|
||||
pushb(235)
|
||||
pushsb(getsym(op1)-(pos+2))
|
||||
}
|
||||
op=="jmp" && wordop {
|
||||
pushb(233)
|
||||
pushw(getsym(op1)-(pos+3))
|
||||
}
|
||||
op=="call" {
|
||||
pushb(232)
|
||||
pushw(getsym(op1)-(pos+3))
|
||||
}
|
||||
op=="neg" {
|
||||
encfs(246, 3)
|
||||
}
|
||||
# opcodes with rel8 encoding
|
||||
op in ops_rel8 && byteop {
|
||||
pushb(ops_rel8[op])
|
||||
pushb(getsym(op1)-(pos+2))
|
||||
}
|
||||
# opcodes without arguments
|
||||
op in ops_sb { pushb(ops_sb[op]) }
|
||||
{
|
||||
if (!hex) err("no encoding found")
|
||||
submit(pos)
|
||||
}
|
||||
END{
|
||||
if (of=="hex") printf("\n")
|
||||
if (errors) exit(1)
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user