; flat assembler core
; Copyright (c) 1999-2006, Tomasz Grysztar.
; All rights reserved.

formatter:
	cmp	[output_file],0
	jne	output_path_ok
	
	push	edi
	mov	esi,[input_file]
	mov	edi,[free_additional_memory]
      copy_output_path:
	lods	byte [esi]
	cmp	edi,[structures_buffer]
	jae	out_of_memory
	stos	byte [edi]
	or	al,al
	jnz	copy_output_path
	dec	edi
	mov	eax,edi
      find_extension:
	dec	eax
	cmp	eax,[free_additional_memory]
	jb	extension_found
	cmp	byte [eax],'\'
	je	extension_found
	cmp	byte [eax],'/'
	je	extension_found
	cmp	byte [eax],'.'
	jne	find_extension
	mov	edi,eax
      extension_found:
	lea	eax,[edi+9]
	cmp	eax,[structures_buffer]
	jae	out_of_memory
	
	cmp	[output_format],2
	je	exe_extension
	
	jb	bin_extension
	
	cmp	[output_format],4
	je	obj_extension
	
	cmp	[output_format],5
	je	o_extension
	
	cmp	[output_format],3
	jne	no_extension
	
	cmp	[subsystem],1
	je	sys_extension
	
	bt	[format_flags],8
	jnc	exe_extension
	mov	eax,'.dll'
	jmp	make_extension
 
      sys_extension:
	mov	eax,'.sys'
	jmp	make_extension
 
      bin_extension:
	mov	eax,'.bin'
	bt	[format_flags],0
	jnc	make_extension
	mov	eax,'.com'
	jmp	make_extension

      obj_extension:
	mov	eax,'.obj'
	jmp	make_extension

      o_extension:
	mov	eax,'.o'
	bt	[format_flags],0
	jnc	make_extension

      no_extension:
	xor	eax,eax
	jmp	make_extension
 
      exe_extension:
	mov	eax,'.exe'
 
      make_extension:
	xchg	eax,[edi]
	scas	dword [edi]
	mov	byte [edi],0
	scas	byte [edi]
	mov	esi,edi
	stos	dword [edi]
	sub	edi,9
	xor	eax,eax
	mov	ebx,characters
      adapt_case:
	mov	al,[esi]
	or	al,al
	jz	adapt_next
	xlat	byte [ebx]
	cmp	al,[esi]
	je	adapt_ok
	sub	byte [edi],20h
      adapt_ok:
	inc	esi
      adapt_next:
	inc	edi
	cmp	byte [edi],0
	jne	adapt_case
	mov	esi,edi
	lea	ecx,[esi+1]
	sub	ecx,[free_additional_memory]
	mov	edi,[structures_buffer]
	dec	edi
	std
	rep	movs byte [edi],[esi]
	cld
	inc	edi
	mov	[structures_buffer],edi
	mov	[output_file],edi
	pop	edi
	
      output_path_ok:
	cmp	[output_format],4
	je	coff_formatter
	
	cmp	[output_format],5
	jne	common_formatter
	
	bt	[format_flags],0
	jnc	elf_formatter
	
      common_formatter:
	mov	eax,edi
	sub	eax,[code_start]
	mov	[real_code_size],eax
	cmp	edi,[undefined_data_end]
	jne	calculate_code_size
	mov	edi,[undefined_data_start]
	
      calculate_code_size:
	sub	edi,[code_start]
	mov	[code_size],edi
	mov	[written_size],0
	mov	edx,[output_file]
	call	create
	jc	write_failed
	
	cmp	[output_format],3
	jne	stub_written
	
	mov	edx,[code_start]
	mov	ecx,[stub_size]
	sub	edx,ecx
	add	[written_size],ecx
	call	write
	
      stub_written:
	cmp	[output_format],2
	jne	write_output
	
	call	write_mz_header
	
      write_output:
	call	write_code
	
      output_written:
	call	close
	ret
	
      write_code:
	mov	eax,[written_size]
	mov	[headers_size],eax
	mov	edx,[code_start]
	mov	ecx,[code_size]
	add	[written_size],ecx
	call	write
	jc	write_failed
	ret
	
format_directive:
	cmp	edi,[code_start]
	jne	unexpected_instruction
	cmp	[virtual_data],0
	jne	unexpected_instruction
	cmp	[output_format],0
	jne	unexpected_instruction
	lods	byte [esi]
	cmp	al,17h
	je	format_prefix
	cmp	al,18h
	jne	invalid_argument
	lods	byte [esi]
      select_format:
	mov	dl,al
	shr	al,4
	mov	[output_format],al
	and	edx,0Fh
	or	[format_flags],edx
	cmp	al,2
	je	format_mz
	cmp	al,3
	je	format_pe
	cmp	al,4
	je	format_coff
	cmp	al,5
	je	format_elf
	jmp	instruction_assembled
      format_prefix:
	lods	byte [esi]
	mov	ah,al
	lods	byte [esi]
	cmp	al,18h
	jne	invalid_argument
	lods	byte [esi]
	mov	edx,eax
	shr	dl,4
	shr	dh,4
	cmp	dl,dh
	jne	invalid_argument
	or	al,ah
	jmp	select_format
entry_directive:
	bts	[format_flags],10h
	jc	setting_already_specified
	mov	al,[output_format]
	cmp	al,2
	je	mz_entry
	cmp	al,3
	je	pe_entry
	cmp	al,5
	jne	illegal_instruction
	bt	[format_flags],0
	jc	elf_entry
	jmp	illegal_instruction
stack_directive:
	bts	[format_flags],11h
	jc	setting_already_specified
	mov	al,[output_format]
	cmp	al,2
	je	mz_stack
	cmp	al,3
	je	pe_stack
	jmp	illegal_instruction
heap_directive:
	bts	[format_flags],12h
	jc	setting_already_specified
	mov	al,[output_format]
	cmp	al,2
	je	mz_heap
	cmp	al,3
	je	pe_heap
	jmp	illegal_instruction
segment_directive:
	cmp	[virtual_data],0
	jne	illegal_instruction
	mov	al,[output_format]
	cmp	al,2
	je	mz_segment
	cmp	al,5
	je	elf_segment
	jmp	illegal_instruction
section_directive:
	cmp	[virtual_data],0
	jne	illegal_instruction
	mov	al,[output_format]
	cmp	al,3
	je	pe_section
	cmp	al,4
	je	coff_section
	cmp	al,5
	je	elf_section
	jmp	illegal_instruction
public_directive:
	mov	al,[output_format]
	cmp	al,4
	je	public_allowed
	cmp	al,5
	jne	illegal_instruction
	bt	[format_flags],0
	jc	illegal_instruction
      public_allowed:
	lods	byte [esi]
	cmp	al,2
	jne	invalid_argument
	lods	dword [esi]
	cmp	eax,0Fh
	jb	invalid_use_of_symbol
	je	reserved_word_used_as_symbol
	mov	dx,[current_pass]
	mov	[eax+18],dx
	or	byte [eax+8],8
	inc	esi
	mov	ebx,[free_additional_memory]
	lea	edx,[ebx+10h]
	cmp	edx,[structures_buffer]
	jae	out_of_memory
	mov	[free_additional_memory],edx
	mov	[ebx+8],eax
	mov	eax,[current_line]
	mov	[ebx+0Ch],eax
	lods	byte [esi]
	cmp	al,86h
	jne	invalid_argument
	lods	word [esi]
	cmp	ax,'('
	jne	invalid_argument
	mov	[ebx+4],esi
	lods	dword [esi]
	lea	esi,[esi+eax+1]
	mov	byte [ebx],80h
	jmp	instruction_assembled
extrn_directive:
	mov	al,[output_format]
	cmp	al,4
	je	extrn_allowed
	cmp	al,5
	jne	illegal_instruction
	bt	[format_flags],0
	jc	illegal_instruction
      extrn_allowed:
	lods	word [esi]
	cmp	ax,'('
	jne	invalid_argument
	mov	ebx,esi
	lods	dword [esi]
	lea	esi,[esi+eax+1]
	mov	edx,[free_additional_memory]
	lea	eax,[edx+0Ch]
	cmp	eax,[structures_buffer]
	jae	out_of_memory
	mov	[free_additional_memory],eax
	mov	byte [edx],81h
	mov	[edx+4],ebx
	lods	byte [esi]
	cmp	al,86h
	jne	invalid_argument
	lods	byte [esi]
	cmp	al,2
	jne	invalid_argument
	lods	dword [esi]
	cmp	eax,0Fh
	jb	invalid_use_of_symbol
	je	reserved_word_used_as_symbol
	inc	esi
	mov	ebx,eax
	xor	ah,ah
	lods	byte [esi]
	cmp	al,':'
	je	get_extrn_size
	dec	esi
	cmp	al,11h
	jne	extrn_size_ok
      get_extrn_size:
	lods	word [esi]
	cmp	al,11h
	jne	invalid_argument
      extrn_size_ok:
	mov	[address_symbol],edx
	movzx	ecx,ah
	mov	[edx+8],ecx
	xor	eax,eax
	xor	edx,edx
	xor	ebp,ebp
	mov	ch,2
	test	[format_flags],8
	jz	make_free_label
	mov	ch,4
	jmp	make_free_label
mark_relocation:
	cmp	[value_type],0
	je	relocation_ok
	cmp	[virtual_data],0
	jne	relocation_ok
	cmp	[output_format],2
	je	mark_mz_relocation
	cmp	[output_format],3
	je	mark_pe_relocation
	cmp	[output_format],4
	je	mark_coff_relocation
	cmp	[output_format],5
	je	mark_elf_relocation
      relocation_ok:
	ret
close_pass:
	mov	al,[output_format]
	cmp	al,3
	je	close_pe
	cmp	al,4
	je	close_coff
	cmp	al,5
	je	close_elf
	ret

format_mz:
	mov	edx,[additional_memory]
	push	edi
	mov	edi,edx
	mov	ecx,1Ch shr 2
	xor	eax,eax
	rep	stos dword [edi]
	mov	[free_additional_memory],edi
	pop	edi
	mov	word [edx+0Ch],0FFFFh
	mov	word [edx+10h],1000h
	mov	[code_type],16
	jmp	instruction_assembled
mark_mz_relocation:
	push	eax ebx
	inc	[number_of_relocations]
	mov	ebx,[free_additional_memory]
	mov	eax,edi
	sub	eax,[code_start]
	mov	[ebx],ax
	shr	eax,16
	shl	ax,12
	mov	[ebx+2],ax
	cmp	word [ebx],0FFFFh
	jne	mz_relocation_ok
	inc	word [ebx+2]
	sub	word [ebx],10h
      mz_relocation_ok:
	add	ebx,4
	cmp	ebx,[structures_buffer]
	jae	out_of_memory
	mov	[free_additional_memory],ebx
	pop	ebx eax
	ret
mz_segment:
	lods	byte [esi]
	cmp	al,2
	jne	invalid_argument
	lods	dword [esi]
	cmp	eax,0Fh
	jb	invalid_use_of_symbol
	je	reserved_word_used_as_symbol
	inc	esi
	mov	ebx,eax
	mov	eax,edi
	sub	eax,[code_start]
	mov	ecx,0Fh
	add	eax,0Fh
	and	eax,1111b
	sub	ecx,eax
	mov	edx,edi
	xor	al,al
	rep	stos byte [edi]
	mov	dword [org_origin],edi
	mov	dword [org_origin+4],0
	mov	[org_registers],0
	mov	[org_start],edi
	mov	eax,edx
	call	undefined_data
	mov	eax,edi
	sub	eax,[code_start]
	shr	eax,4
	cmp	eax,10000h
	jae	value_out_of_range
	mov	edx,eax
	mov	al,16
	cmp	byte [esi],13h
	jne	segment_type_ok
	inc	esi
	lods	byte [esi]
      segment_type_ok:
	mov	[code_type],al
	mov	eax,edx
	mov	cx,0100h
	xor	edx,edx
	xor	ebp,ebp
	mov	[address_symbol],edx
	jmp	make_free_label
mz_entry:
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	call	get_word_value
	cmp	[value_type],1
	je	initial_cs_ok
	cmp	[error_line],0
	jne	initial_cs_ok
	mov	eax,[current_line]
	mov	[error_line],eax
	mov	[error],invalid_address
      initial_cs_ok:
	mov	edx,[additional_memory]
	mov	[edx+16h],ax
	lods	byte [esi]
	cmp	al,':'
	jne	invalid_argument
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	ja	invalid_address
	call	get_word_value
	cmp	[value_type],0
	jne	invalid_use_of_symbol
	mov	edx,[additional_memory]
	mov	[edx+14h],ax
	jmp	instruction_assembled
mz_stack:
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	call	get_word_value
	cmp	byte [esi],':'
	je	stack_pointer
	cmp	ax,10h
	jb	invalid_value
	cmp	[value_type],0
	jne	invalid_use_of_symbol
	mov	edx,[additional_memory]
	mov	[edx+10h],ax
	jmp	instruction_assembled
      stack_pointer:
	cmp	[value_type],1
	je	initial_ss_ok
	cmp	[error_line],0
	jne	initial_ss_ok
	mov	eax,[current_line]
	mov	[error_line],eax
	mov	[error],invalid_address
      initial_ss_ok:
	mov	edx,[additional_memory]
	mov	[edx+0Eh],ax
	lods	byte [esi]
	cmp	al,':'
	jne	invalid_argument
	lods	byte [esi]
	cmp	al,'('
	jne	invalid_argument
	call	get_word_value
	cmp	[value_type],0
	jne	invalid_use_of_symbol
	mov	edx,[additional_memory]
	mov	[edx+10h],ax
	bts	[format_flags],4
	jmp	instruction_assembled
mz_heap:
	cmp	[output_format],2
	jne	illegal_instruction
	lods	byte [esi]
	call	get_size_operator
	cmp	ah,1
	je	invalid_value
	cmp	ah,2
	ja	invalid_value
	cmp	al,'('
	jne	invalid_argument
	call	get_word_value
	cmp	[value_type],0
	jne	invalid_use_of_symbol
	mov	edx,[additional_memory]
	mov	[edx+0Ch],ax
	jmp	instruction_assembled
write_mz_header:
	mov	edx,[additional_memory]
	bt	[format_flags],4
	jc	mz_stack_ok
	mov	eax,[real_code_size]
	dec	eax
	shr	eax,4
	inc	eax
	mov	[edx+0Eh],ax
	shl	eax,4
	movzx	ecx,word [edx+10h]
	add	eax,ecx
	mov	[real_code_size],eax
      mz_stack_ok:
	mov	edi,[free_additional_memory]
	mov	eax,[number_of_relocations]
	shl	eax,2
	add	eax,1Ch
	sub	edi,eax
	xchg	edi,[free_additional_memory]
	mov	ecx,0Fh
	add	eax,0Fh
	and	eax,1111b
	sub	ecx,eax
	xor	al,al
	rep	stos byte [edi]
	sub	edi,[free_additional_memory]
	mov	ecx,edi
	shr	edi,4
	mov	word [edx],'MZ' 	; signature
	mov	[edx+8],di		; header size in paragraphs
	mov	eax,[number_of_relocations]
	mov	[edx+6],ax		; number of relocation entries
	mov	eax,[code_size]
	add	eax,ecx
	mov	esi,eax
	shr	esi,9
	and	eax,1FFh
	inc	si
	or	ax,ax
	jnz	mz_size_ok
	mov	ax,200h
	dec	si
      mz_size_ok:
	mov	[edx+2],ax		; number of bytes in last page
	mov	[edx+4],si		; number of pages
	mov	eax,[real_code_size]
	dec	eax
	shr	eax,4
	inc	eax
	mov	esi,[code_size]
	dec	esi
	shr	esi,4
	inc	esi
	sub	eax,esi
	mov	[edx+0Ah],ax		; minimum memory in addition to code
	add	[edx+0Ch],ax		; maximum memory in addition to code
	salc
	mov	ah,al
	or	[edx+0Ch],ax
	mov	word [edx+18h],1Ch	; offset of relocation table
	add	[written_size],ecx
	call	write
	jc	write_failed
	ret

make_stub:
	mov	[stub_file],edx
	or	edx,edx
	jnz	stub_from_file
	push	esi
	mov	edx,edi
	xor	eax,eax
	mov	ecx,20h
	rep	stos dword [edi]
	mov	eax,40h+default_stub_end-default_stub
	mov	cx,100h+default_stub_end-default_stub
	mov	word [edx],'MZ'
	mov	word [edx+4],1
	mov	word [edx+2],ax
	mov	word [edx+8],4
	mov	word [edx+0Ah],10h
	mov	word [edx+0Ch],0FFFFh
	mov	word [edx+10h],cx
	mov	word [edx+3Ch],ax
	mov	word [edx+18h],40h
	lea	edi,[edx+40h]
	mov	esi,default_stub
	mov	ecx,default_stub_end-default_stub
	rep	movs byte [edi],[esi]
	pop	esi
	jmp	stub_ok