assemble.inc

一个用纯汇编 写的操作系统 源代码 是用 TASM 编译器写的

	movzx	ecx,[operand_size]
	cmp	ecx,eax
	ja	bad_load_address
	rep	movs byte [edi],[esi]
	jmp	value_loaded
      bad_load_address:
	cmp	[error_line],0
	jne	value_loaded
	mov	eax,[current_line]
	mov	[error_line],eax
	mov	[error],value_out_of_range
      value_loaded:
	pop	edi esi
	mov	eax,dword [value]
	mov	edx,dword [value+4]
	pop	ebx
	xor	cx,cx
	jmp	make_constant
store_directive:
	cmp	byte [esi],11h
	je	sized_store
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	call	get_byte_value
	xor	edx,edx
	movzx	eax,al
	mov	[operand_size],1
	jmp	store_value_ok
      sized_store:
	call	get_value
      store_value_ok:
	cmp	[value_type],0
	jne	invalid_use_of_symbol
	mov	dword [value],eax
	mov	dword [value+4],edx
	lods	word [esi]
	cmp	ax,80h+'(' shl 8
	jne	invalid_argument
	cmp	byte [esi],'.'
	je	invalid_value
	call	get_qword_value
	call	calculate_relative_offset
	push	esi edi
	cmp	[next_pass_needed],0
	jne	store_address_type_ok
	cmp	[value_type],0
	jne	invalid_use_of_symbol
      store_address_type_ok:
	cmp	edx,-1
	jne	bad_store_address
	neg	eax
	sub	edi,eax
	jc	bad_store_address
	cmp	edi,[org_start]
	jb	bad_store_address
	mov	esi,value
	movzx	ecx,[operand_size]
	cmp	ecx,eax
	ja	bad_store_address
	rep	movs byte [edi],[esi]
	mov	eax,edi
	pop	edi esi
	cmp	edi,[undefined_data_end]
	jne	instruction_assembled
	cmp	eax,[undefined_data_start]
	jbe	instruction_assembled
	mov	[undefined_data_start],eax
	jmp	instruction_assembled
      bad_store_address:
	pop	edi esi
	cmp	[error_line],0
	jne	instruction_assembled
	mov	eax,[current_line]
	mov	[error_line],eax
	mov	[error],value_out_of_range
	jmp	instruction_assembled

display_directive:
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	cmp	byte [esi],0
	jne	display_byte
	inc	esi
	lods	dword [esi]
	mov	ecx,eax
	push	edi
	mov	edi,[display_buffer]
	sub	edi,4
	sub	edi,eax
	mov	[display_buffer],edi
	rep	movs byte [edi],[esi]
	stos	dword [edi]
	pop	edi
	inc	esi
	jmp	display_next
      display_byte:
	call	get_byte_value
	push	edi
	mov	edi,[display_buffer]
	sub	edi,4+1
	mov	[display_buffer],edi
	stos	byte [edi]
	mov	eax,1
	stos	dword [edi]
	pop	edi
      display_next:
	cmp	edi,[display_buffer]
	ja	out_of_memory
	lods	byte [esi]
	cmp	al,','
	je	display_directive
	dec	esi
	jmp	instruction_assembled
flush_display_buffer:
	mov	eax,[display_buffer]
	or	eax,eax
	jz	display_done
	mov	esi,[labels_list]
	cmp	esi,eax
	je	display_done
      display_messages:
	sub	esi,4
	mov	ecx,[esi]
	sub	esi,ecx
	push	esi
	call	display_block
	pop	esi
	cmp	esi,[display_buffer]
	jne	display_messages
	mov	eax,[labels_list]
	mov	[display_buffer],eax
      display_done:
	ret
	
	
	
times_directive:
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	cmp	byte [esi],'.'
	je	invalid_value
	call	get_dword_value
	cmp	[next_pass_needed],0
	jne	times_value_ok
	cmp	[value_type],0
	jne	invalid_use_of_symbol
      times_value_ok:
	cmp	eax,0
	je	zero_times
	jl	negative_times
	cmp	byte [esi],':'
	jne	times_argument_ok
	inc	esi
      times_argument_ok:
	push	[counter]
	push	[counter_limit]
	mov	[counter_limit],eax
	mov	[counter],1
      times_loop:
	mov	eax,esp
	sub	eax,100h
	jc	stack_overflow
	cmp	eax,[stack_limit]
	jb	stack_overflow
	push	esi
	or	[prefixed_instruction],-1
	call	continue_line
	mov	eax,[counter_limit]
	cmp	[counter],eax
	je	times_done
	inc	[counter]
	pop	esi
	jmp	times_loop
      times_done:
	pop	eax
	pop	[counter_limit]
	pop	[counter]
	jmp	instruction_assembled
      negative_times:
	cmp	[error_line],0
	jne	zero_times
	mov	eax,[current_line]
	mov	[error_line],eax
	mov	[error],invalid_value
      zero_times:
	call	skip_line
	jmp	instruction_assembled

virtual_directive:
	lods	byte [esi]
	cmp	al,80h
	jne	virtual_at_current
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	cmp	byte [esi],'.'
	je	invalid_value
	call	get_address_value
	mov	ebp,[address_symbol]
	xor	ch,ch
	or	bh,bh
	jz	set_virtual
	mov	ch,1
	jmp	set_virtual
      virtual_at_current:
	dec	esi
	mov	al,[labels_type]
	mov	[value_type],al
	mov	ebp,[org_symbol]
	mov	eax,edi
	xor	edx,edx
	sub	eax,dword [org_origin]
	sbb	edx,dword [org_origin+4]
	mov	bx,word [org_registers]
	mov	cx,word [org_registers+2]
	xchg	bh,bl
	xchg	ch,cl
      set_virtual:
	push	[org_registers]
	mov	byte [org_registers],bh
	mov	byte [org_registers+1],bl
	mov	byte [org_registers+2],ch
	mov	byte [org_registers+3],cl
	call	allocate_structure_data
	mov	word [ebx],virtual_directive-assembler
	not	eax
	not	edx
	add	eax,1
	adc	edx,0
	add	eax,edi
	adc	edx,0
	xchg	dword [org_origin],eax
	xchg	dword [org_origin+4],edx
	mov	[ebx+10h],eax
	mov	[ebx+14h],edx
	pop	eax
	mov	[ebx+18h],eax
	mov	al,[virtual_data]
	mov	[ebx+2],al
	mov	al,[labels_type]
	mov	[ebx+3],al
	mov	eax,edi
	xchg	eax,[org_start]
	mov	[ebx+0Ch],eax
	xchg	ebp,[org_symbol]
	mov	[ebx+1Ch],ebp
	mov	[ebx+8],edi
	mov	eax,[current_line]
	mov	[ebx+4],eax
	or	[virtual_data],-1
	mov	al,[value_type]
	test	al,1
	jnz	invalid_use_of_symbol
	mov	[labels_type],al
	jmp	instruction_assembled
      allocate_structure_data:
	mov	ebx,[structures_buffer]
	sub	ebx,20h
	cmp	ebx,[free_additional_memory]
	jb	out_of_memory
	mov	[structures_buffer],ebx
	ret
      find_structure_data:
	mov	ebx,[structures_buffer]
      scan_structures:
	cmp	ebx,[additional_memory_end]
	je	no_such_structure
	cmp	ax,[ebx]
	je	structure_data_found
	add	ebx,20h
	jmp	scan_structures
      structure_data_found:
	ret
      no_such_structure:
	stc
	ret
      end_virtual:
	call	find_structure_data
	jc	unexpected_instruction
	mov	al,[ebx+2]
	mov	[virtual_data],al
	mov	al,[ebx+3]
	mov	[labels_type],al
	mov	eax,[ebx+10h]
	mov	dword [org_origin],eax
	mov	eax,[ebx+14h]
	mov	dword [org_origin+4],eax
	mov	eax,[ebx+18h]
	mov	[org_registers],eax
	mov	eax,[ebx+0Ch]
	mov	[org_start],eax
	mov	eax,[ebx+1Ch]
	mov	[org_symbol],eax
	mov	edi,[ebx+8]
      remove_structure_data:
	push	esi edi
	mov	esi,[structures_buffer]
	mov	ecx,ebx
	sub	ecx,esi
	lea	edi,[esi+20h]
	mov	[structures_buffer],edi
	shr	ecx,2
	rep	movs dword [edi],[esi]
	pop	edi esi
	ret
repeat_directive:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	cmp	byte [esi],'.'
	je	invalid_value
	call	get_dword_value
	cmp	[next_pass_needed],0
	jne	repeat_value_ok
	cmp	[value_type],0
	jne	invalid_use_of_symbol
      repeat_value_ok:
	cmp	eax,0
	je	zero_repeat
	jl	negative_repeat
	call	allocate_structure_data
	mov	word [ebx],repeat_directive-assembler
	xchg	eax,[counter_limit]
	mov	[ebx+10h],eax
	mov	eax,1
	xchg	eax,[counter]
	mov	[ebx+14h],eax
	mov	[ebx+8],esi
	mov	eax,[current_line]
	mov	[ebx+4],eax
	jmp	instruction_assembled
      end_repeat:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	call	find_structure_data
	jc	unexpected_instruction
	mov	eax,[counter_limit]
	inc	[counter]
	cmp	[counter],eax
	jbe	continue_repeating
      stop_repeat:
	mov	eax,[ebx+10h]
	mov	[counter_limit],eax
	mov	eax,[ebx+14h]
	mov	[counter],eax
	call	remove_structure_data
	jmp	instruction_assembled
      continue_repeating:
	mov	esi,[ebx+8]
	jmp	instruction_assembled
      negative_repeat:
	cmp	[error_line],0
	jne	zero_repeat
	mov	eax,[current_line]
	mov	[error_line],eax
	mov	[error],invalid_value
      zero_repeat:
	mov	al,[esi]
	or	al,al
	jz	missing_end_directive
	cmp	al,0Fh
	jne	extra_characters_on_line
	call	find_end_repeat
	jmp	instruction_assembled
      find_end_repeat:
	call	find_structure_end
	cmp	ax,repeat_directive-assembler
	jne	unexpected_instruction
	ret
while_directive:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	call	allocate_structure_data
	mov	word [ebx],while_directive-assembler
	mov	eax,1
	xchg	eax,[counter]
	mov	[ebx+10h],eax
	mov	[ebx+8],esi
	mov	eax,[current_line]
	mov	[ebx+4],eax
      do_while:
	push	ebx
	call	calculate_logical_expression
	or	al,al
	jnz	while_true
	mov	al,[esi]
	or	al,al
	jz	missing_end_directive
	cmp	al,0Fh
	jne	extra_characters_on_line
      stop_while:
	call	find_end_while
	pop	ebx
	mov	eax,[ebx+10h]
	mov	[counter],eax
	call	remove_structure_data
	jmp	instruction_assembled
      while_true:
	pop	ebx
	jmp	instruction_assembled
      end_while:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	call	find_structure_data
	jc	unexpected_instruction
	mov	eax,[ebx+4]
	mov	[current_line],eax
	inc	[counter]
	jz	too_many_repeats
	mov	esi,[ebx+8]
	jmp	do_while
      find_end_while:
	call	find_structure_end
	cmp	ax,while_directive-assembler
	jne	unexpected_instruction
	ret
if_directive:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	call	calculate_logical_expression
	mov	dl,al
	mov	al,[esi]
	or	al,al
	jz	missing_end_directive
	cmp	al,0Fh
	jne	extra_characters_on_line
	or	dl,dl
	jnz	if_true
	call	find_else
	jc	instruction_assembled
	mov	al,[esi]
	cmp	al,1
	jne	else_true
	cmp	word [esi+1],if_directive-assembler
	jne	else_true
	add	esi,4
	jmp	if_directive
      if_true:
	xor	al,al
      make_if_structure:
	call	allocate_structure_data
	mov	word [ebx],if_directive-assembler
	mov	byte [ebx+2],al
	mov	eax,[current_line]
	mov	[ebx+4],eax
	jmp	instruction_assembled
      else_true:
	or	al,al
	jz	missing_end_directive
	cmp	al,0Fh
	jne	extra_characters_on_line
	or	al,-1
	jmp	make_if_structure
      else_directive:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	mov	ax,if_directive-assembler
	call	find_structure_data
	jc	unexpected_instruction
	cmp	byte [ebx+2],0
	jne	unexpected_instruction
      found_else:
	mov	al,[esi]
	cmp	al,1
	jne	skip_else
	cmp	word [esi+1],if_directive-assembler
	jne	skip_else
	add	esi,4
	call	find_else
	jnc	found_else
	call	remove_structure_data
	jmp	instruction_assembled
      skip_else:
	or	al,al
	jz	missing_end_directive
	cmp	al,0Fh
	jne	extra_characters_on_line
	call	find_end_if
	call	remove_structure_data
	jmp	instruction_assembled
      end_if:
	cmp	[prefixed_instruction],0
	jne	unexpected_instruction
	call	find_structure_data
	jc	unexpected_instruction
	call	remove_structure_data
	jmp	instruction_assembled
      find_else:
	call	find_structure_end
	cmp	ax,else_directive-assembler
	je	else_found
	cmp	ax,if_directive-assembler
	jne	unexpected_instruction
	stc
	ret
      else_found:
	clc
	ret
      find_end_if:
	call	find_structure_end
	cmp	ax,if_directive-assembler
	jne	unexpected_instruction
	ret
      find_structure_end:
	push	[error_line]
	mov	eax,[current_line]
	mov	[error_line],eax
      find_end_directive:
	call	skip_line
	lods	byte [esi]
	cmp	al,0Fh
	jne	no_end_directive
	lods	dword [esi]
	mov	[current_line],eax
      skip_labels:
	cmp	byte [esi],2
	jne	labels_ok
	add	esi,6
	jmp	skip_labels
      labels_ok:
	cmp	byte [esi],1
	jne	find_end_directive
	mov	ax,[esi+1]
	cmp	ax,prefix_instruction-assembler
	je	find_end_directive
	add	esi,4
	cmp	ax,repeat_directive-assembler
	je	skip_repeat
	cmp	ax,while_directive-assembler
	je	skip_while
	cmp	ax,if_directive-assembler
	je	skip_if
	cmp	ax,else_directive-assembler
	je	structure_end
	cmp	ax,end_directive-assembler
	jne	find_end_directive
	cmp	byte [esi],1
	jne	find_end_directive
	mov	ax,[esi+1]
	add	esi,4
	cmp	ax,repeat_directive-assembler
	je	structure_end
	cmp	ax,while_directive-assembler
	je	structure_end
	cmp	ax,if_directive-assembler
	jne	find_end_directive
      structure_end:
	pop	[error_line]
	ret
      no_end_directive:
	mov	eax,[error_line]
	mov	[current_line],eax
	jmp	missing_end_directive
      skip_repeat:
	call	find_end_repeat
	jmp	find_end_directive
      skip_while:
	call	find_end_while
	jmp	find_end_directive
      skip_if:
	call	skip_if_block
	jmp	find_end_directive
      skip_if_block:
	call	find_else
	jc	if_block_skipped
	cmp	byte [esi],1
	jne	skip_after_else
	cmp	word [esi+1],if_directive-assembler
	jne	skip_after_else
	add	esi,4
	jmp	skip_if_block
      skip_after_else:
	call	find_end_if
      if_block_skipped:
	ret
end_directive:
	lods	byte [esi]
	cmp	al,1
	jne	invalid_argument
	lods	word [esi]
	inc	esi
	cmp	ax,virtual_directive-assembler
	je	end_virtual
	cmp	ax,repeat_directive-assembler
	je	end_repeat
	cmp	ax,while_directive-assembler
	je	end_while
	cmp	ax,if_directive-assembler
	je	end_if
	cmp	ax,data_directive-assembler
	je	end_data
	jmp	invalid_argument
break_directive:
	mov	ebx,[structures_buffer]
	mov	al,[esi]
	or	al,al
	jz	find_breakable_structure
	cmp	al,0Fh
	jne	extra_characters_on_line
      find_breakable_structure:
	cmp	ebx,[additional_memory_end]
	je	unexpected_instruction
	mov	ax,[ebx]
	cmp	ax,repeat_directive-assembler
	je	break_repeat
	cmp	ax,while_directive-assembler
	je	break_while
	cmp	ax,if_directive-assembler
	je	break_if
	add	ebx,20h
	jmp	find_breakable_structure
      break_if:
	push	[current_line]
	mov	eax,[ebx+4]
	mov	[current_line],eax
	call	remove_structure_data
	call	skip_if_block
	pop	[current_line]
	mov	ebx,[structures_buffer]
	jmp	find_breakable_structure
      break_repeat:
	push	ebx
	call	find_end_repeat
	pop	ebx
	jmp	stop_repeat
      break_while:
	push	ebx
	jmp	stop_while

data_bytes:
	call	define_data
	lods	byte [esi]
	cmp	al,'('
	je	get_byte
	cmp	al,'?'
	jne	invalid_argument
	mov	eax,edi
	mov	byte [edi],0
	inc	edi
	jmp	undefined_data
      get_byte:
	cmp	byte [esi],0
	je	get_string
	call	get_byte_value
	stos	byte [edi]
	ret
      get_string:
	inc	esi
	lods	dword [esi]
	mov	ecx,eax
	lea	eax,[edi+ecx]
	cmp	eax,[display_buffer]
	ja	out_of_memory
	rep	movs byte [edi],[esi]
	inc	esi
	ret
      undefined_data:
	cmp	[virtual_data],0