; flat assembler
; Copyright (c) 1999-2020, Tomasz Grysztar
; All rights reserved.

init_memory:

;        mov ecx, 16*1024*1024
;
; allocate_memory:
	mcall	SF_SYSTEM, SSF_GET_FREE_RAM
	cmp	eax, 0x38000000 shr 9
	jbe	@f
	mov	eax, 0x38000000 shr 9
@@:
	shl	eax, 9
	xchg	eax, ecx
	mov	[memory_setting],ecx
	mcall	SF_SYS_MISC, SSF_MEM_ALLOC
	or	eax,eax
	jz	out_of_memory
	mov	[memblock], eax
	mov	[additional_memory],eax
	add	eax,[memory_setting]
	mov	[memory_end],eax
	mov	eax,[memory_setting]
	shr	eax,2
	add	eax,[additional_memory]
	mov	[additional_memory_end],eax
	mov	[memory_start],eax
	retn

exit_program:
	cmp	[_mode],NORMAL_MODE
	jne	@f
	mcall	SF_SYS_MISC, SSF_MEM_FREE, [memblock]
	mov	esp,[processing_esp]
	jmp	still
@@:
	or	eax,-1
	mcall

make_timestamp:
	push	ebx
	mcall	SF_SYSTEM_GET,SSF_TIME_COUNT
	imul	eax,10
	pop	ebx
	retn

symbol_dump:

	push	edi
	mov	edx,[memory_end]
      symb_dump:
	cmp	edx,[labels_list]
	jbe	symbols_dumped
	sub	edx,LABEL_STRUCTURE_SIZE
	cmp	dword [edx+24],0
	je	symb_dump	; do not dump anonymous symbols
	test	byte [edx+8],1
	jz	symb_dump	; do not dump symbols that didn't get defined
	mov	ax,[current_pass]
	cmp	ax,[edx+16]
	jne	symb_dump
	test	byte [edx+8],4 or 2
	jnz	symb_dump	; do not dump assembly-time variables
				; do not dump variables defined with '='
	cmp	word [edx+12], 0
	jnz	symb_dump	; do not dump register-based variables

	mov	al, '0'
	stosb
	mov	al, 'x'
	stosb
	mov	eax, [edx+4]
	mov	ecx, 8
@@:
	rol	eax, 4
	test	al, 0xF
	loopz	@b
	jz	.nohigh
	inc	ecx
@@:
	push	eax
	and	al, 0xF
	cmp	al, 10
	sbb	al, 69h
	das
	stosb
	pop	eax
	rol	eax, 4
	loop	@b
	mov	eax, [edx]
	mov	ecx, 8
	jmp	.low
.nohigh:
	mov	eax, [edx]
	mov	ecx, 8
@@:
	rol	eax, 4
	test	al, 0xF
	loopz	@b
	inc	ecx
.low:
	push	eax
	and	al, 0xF
	cmp	al, 10
	sbb	al, 69h
	das
	stosb
	pop	eax
	rol	eax, 4
	loop	.low

	mov	al, ' '
	stosb

	mov	esi,[edx+24]
	movzx	ecx,byte [esi-1]
	rep	movsb

	mov	ax,0A0Dh
	stosw

	jmp	symb_dump

      symbols_dumped:
	mov	edx,dbgfilename
	push	esi edi
	mov	esi, outfile
	mov	edi, edx
@@:
	lodsb
	stosb
	test	al, al
	jnz	@b
	lea	ecx, [edi-1]
@@:
	dec	edi
	cmp	edi, edx
	jb	@f
	cmp	byte [edi], '/'
	jz	@f
	cmp	byte [edi], '.'
	jnz	@b
	mov	ecx, edi
@@:
	mov	dword [ecx], '.dbg'
	mov	byte [ecx+4], 0
	pop	edi esi
	call	create
	mov	edx,[esp]
	mov	ecx,edi
	sub	ecx,edx
	call	write
	call	close
	pop	edi

	retn

get_environment_variable:
	mov	ecx,[memory_end]
	sub	ecx,edi
	cmp	ecx,7
	jb	out_of_memory
	cmp	dword[esi],'INCL'
	jne	.finish
	mov	esi,_ramdisk
	mov	ecx,6
	cld
	rep	movsb
  .finish:
;       stc
	retn

alloc_handle:
; in:
; out: ebx = file handle
; on error: return to caller of caller with cf set
; preserves: esi, edi
	call	make_fullpaths
	mov	ebx, file_IO_slots+4
	jmp	check_file_IO_slot
      next_file_IO_slot:
	add	ebx, 4+20+MAX_PATH
	cmp	ebx, file_IO_end
	jae	send_error_to_caller_of_caller
      check_file_IO_slot:
	cmp	[ebx+FILEIO.cmd], -1
	jnz	next_file_IO_slot
	and	[ebx+FILEIO.offset], 0
	and	[ebx+FILEIO.flags], 0
      adapt_path:
	push	esi edi ecx
	mov	esi, fullpath_open
	lea	edi, [ebx+namedFILEIO.name]
	mov	ecx, MAX_PATH
      copy_path:
	lodsb
	cmp	al,'\'
	jne	path_char_ok
	mov	al,'/'
      path_char_ok:
	stosb
	or	al,al
	loopnz	copy_path
	pop	ecx edi esi
	jz	adapt_path.done
      send_error_to_caller_of_caller:
	stc
	pop	eax
      adapt_path.done:
	ret

create:
; in:
; out: ebx = file handle, cf set on error
; preserves: esi, edi
	call	alloc_handle
	and	[ebx+FILEIO.filesize], 0
	mov	[ebx+FILEIO.cmd], SSF_CREATE_FILE
	retn


open:
; in:
; out: ebx = file handle, cf set on error
; preserves: esi, edi
	call	alloc_handle
	mov	[ebx+FILEIO.cmd], SSF_GET_INFO
	and	[ebx+FILEIO.count], 0
	mov	[ebx+FILEIO.buffer], fileinfo
	push	ebx
	mcall	SF_FILE
	pop	ebx
	test	eax, eax
	jnz	fail_close
	mov	eax, dword[fileinfo.size]
	mov	[ebx+FILEIO.filesize], eax
	and	[ebx+FILEIO.cmd], SSF_READ_FILE
	retn

fail_close:
	stc
close:
; in: ebx = file handle
; preserves: ebx, esi, edi, cf
	mov	[ebx+FILEIO.cmd], -1 ; close handle
	retn
write:
; in: ebx = file handle, edx - data, ecx = number of bytes
; out: cf set on error
; preserves: ebx, esi, edi
	call	read_write
	mov	[ebx+FILEIO.cmd], SSF_WRITE_FILE
	jmp	read_write_check_S_OK
read:
; in: ebx = file handle, edx - buffer, ecx = number of bytes
; out: cf set on error
; preserves: ebx, esi, edi
	call	read_write
	cmp	eax, 6
	jz	read_write_OK
      read_write_check_S_OK:
	test	eax, eax
	jz	read_write_OK
	stc
	retn
      read_write:
	mov	[ebx+FILEIO.count], ecx
	mov	[ebx+FILEIO.buffer], edx
	push	ebx
	mcall	SF_FILE
	xchg	eax, [esp]
	add	[eax+FILEIO.offset], ebx
	adc	[eax+FILEIO.offshigh], 0
	mov	ebx, eax
	pop	eax
      read_write_OK:
	retn


make_fullpaths:
	pusha
	push	edx
	mov	esi,edx
	mov	ecx, MAX_PATH
      copy_edxpath:
	lodsb
	cmp	al,'\'
	jne	edxpath_char_ok
	mov	byte[esi-1],'/'
      edxpath_char_ok:
	or	al,al
	loopnz	copy_edxpath

	mov	esi,path	      ; open
;       DEBUGF  "   '%s'",esi
	mov	edi,fullpath_open
	cld
      newc1:
	movsb
	cmp	byte[esi],0;' '
	jne	newc1
	mov	esi,[esp]

	cmp	byte[esi],'/'
	jne	@f
	cmp	byte[esi],'\'
	jne	@f
	mov	edi,fullpath_open

    @@:
	lodsb
	stosb
	cmp	al,0
	jne	@b

	mov	esi,path	      ; write
	mov	edi,fullpath_write
	cld
      newc2:
	movsb
	cmp	byte[esi],0;' '
	jne	newc2
	mov	esi,[esp]

	cmp	byte[esi],'/'
	jne	@f
	cmp	byte[esi],'\'
	jne	@f
	mov	edi,fullpath_write

    @@:
	lodsb
	stosb
	cmp	al,0
	jne	@b

	mov	esi,path	      ; start
	mov	edi,file_io_start.path
	cld
      newc3:
	movsb
	cmp  byte[esi],0;' '
	jne  newc3
	pop	esi

	cmp	byte[esi],'/'
	jne	@f
	cmp	byte[esi],'\'
	jne	@f
	mov	edi,file_io_start.path

    @@:
	lodsb
	stosb
	cmp	al,0
	jne	@b
	popa
	retn
lseek:
; in: ebx = file handle, al = method, edx = delta offset
; out: cf set on error
; preserves: ebx, esi, edi
	cmp	al,FILE_BEGIN
	jnz	@f
	and	[ebx+FILEIO.offset], 0
	jmp	.common
    @@: cmp	al,FILE_END
	jnz	@f
	mov	eax, [ebx+FILEIO.filesize]
	mov	[ebx+FILEIO.offset], eax
	jmp	.common
    @@:
    .common:
	add	[ebx+FILEIO.offset], edx
	retn

display_character:
	pusha
	cmp	[_mode],NORMAL_MODE
	jne	@f
	cmp	al,$D
	jz	dc2
	cmp	al,$A
	jnz	dc1
	and	[textxy],0x0000FFFF
	add	[textxy], 8 shl 16 and 0xFFFF0000 + 18
	popa
	retn
dc1:
	mov	[dc],al
	mov	eax,[textxy]
	cmp	ax,word[bottom_right]
	ja	dc2
	shr	eax,16
	cmp	ax,word[bottom_right+2]
	ja	dc2
	mov	ecx,[sc.work_text]
	or	ecx,$10000000
	mcall	SF_DRAW_TEXT,[textxy],,dc,1
	add	[textxy],0x00080000
dc2:
	popa
	retn
@@:
	mov	cl,al
	mcall	SF_BOARD,SSF_DEBUG_WRITE
	popa
	retn


display_string:
; in:
;  esi - ASCIIZ string
; preserves: ebx, esi
	push	esi
@@:	lodsb
	test	al,al
	je	@f
	call	display_character
	jmp	@b
@@:
	pop	esi
	retn

display_number:
	push	ebx
	mov	ecx,1000000000
	xor	edx,edx
	xor	bl,bl
display_loop:
	div	ecx
	push	edx
	cmp	ecx,1
	je	display_digit
	or	bl,bl
	jnz	display_digit
	or	al,al
	jz	digit_ok
	not	bl
display_digit:
	add	al,'0'
	push	ebx ecx
	call	display_character
	pop	ecx ebx
digit_ok:
	mov	eax,ecx
	xor	edx,edx
	mov	ecx,10
	div	ecx
	mov	ecx,eax
	pop	eax
	or	ecx,ecx
	jnz	display_loop
	pop	ebx
	retn

display_user_messages:
;    push   [skinh]
;    pop    [textxy]
;    add    [textxy], 7 shl 16 +53
	mov	[displayed_count],0
	call	show_display_buffer
	cmp	[displayed_count],1
	jb	line_break_ok
	je	make_line_break
	mov	ax,word[last_displayed]
	cmp	ax,0A0Dh
	je	line_break_ok
	cmp	ax,0D0Ah
	je	line_break_ok
make_line_break:
	mov	esi,crlf
	call	display_string
line_break_ok:
	retn

display_block:
; in:
;  esi - string
;  ecx = string length
	push	esi
@@:	lodsb
	call	display_character
	loop	@b
	pop	esi
	retn

fatal_error:
; no return, trashes stack

	mov	esi,error_prefix
	call	display_string
	pop	esi
	call	display_string
	mov	esi,error_suffix
	call	display_string
	mov	esi,crlf
	call	display_string
	mov	al,0FFh
	jmp	exit_program

assembler_error:
	call	display_user_messages
	push	0
	mov	ebx,[current_line]
get_error_lines:
	push	ebx
	test	byte [ebx+7],80h
	jz	display_error_line
	mov	edx,ebx
find_definition_origin:
	mov	edx,[edx+12]
	test	byte [edx+7],80h
	jnz	find_definition_origin
	push	edx
	mov	ebx,[ebx+8]
	jmp	get_error_lines
display_error_line:
	mov	esi,[ebx]
	call	display_string
	mov	esi,line_number_start
	call	display_string
	mov	eax,[ebx+4]
	and	eax,7FFFFFFFh
	call	display_number
	mov	al,']'
	call	display_character
	pop	esi
	cmp	ebx,esi
	je	line_number_ok
	mov	al,' '
	call	display_character
	push	esi
	mov	esi,[esi]
	movzx	ecx,byte [esi]
	inc	esi
	call	display_block
	mov	esi,line_number_start
	call	display_string
	pop	esi
	mov	eax,[esi+4]
	and	eax,7FFFFFFFh
	call	display_number
	mov	al,']'
	call	display_character
line_number_ok:
	mov	esi,line_data_start
	call	display_string
	mov	esi,ebx
	mov	edx,[esi]
	call	open
	mov	al,2
	xor	edx,edx
	call	lseek
	mov	edx,[esi+8]
	sub	eax,edx
	push	eax
	xor	al,al
	call	lseek
	mov	ecx,[esp]
	mov	edx,[additional_memory]
	lea	eax,[edx+ecx]
	cmp	eax,[additional_memory_end]
	ja	out_of_memory
	call	read
	call	close
	pop	ecx
	mov	esi,[additional_memory]
get_line_data:
	mov	al,[esi]
	cmp	al,$A
	je	display_line_data
	cmp	al,$D
	je	display_line_data
	cmp	al,$1A
	je	display_line_data
	or	al,al
	jz	display_line_data
	inc	esi
	loop	get_line_data
display_line_data:
	mov	ecx,esi
	mov	esi,[additional_memory]
	sub	ecx,esi
	call	display_block
	mov	esi,crlf
	call	display_string
	pop	ebx
	or	ebx,ebx
	jnz	display_error_line
	mov	esi,error_prefix
	call	display_string
	pop	esi
	call	display_string
	mov	esi,error_suffix
	call	display_string
	jmp	exit_program