Linker/pass1.asm

	keep	obj/pass1
	mcopy pass1.mac
****************************************************************
*
*  Pass 1
*
*  This module contains the subroutines used to do pass 1
*  processing of the input files.
*
****************************************************************
	copy	directPage
****************************************************************
*
*  Align - align the code to a byte boundary
*
*  Inputs:
*	sp - pointer to the opcode
*	pc - current program counter
*
*  Outputs:
*	sp - pointer to the next opcode
*	pc - new program counter
*
****************************************************************
*
Align	private

	ldy	#1	get the alignment factor
	lda	[sp],Y
	sta	r0
	iny
	iny
	lda	[sp],Y
	sta	r2
	add4	sp,#5
	jsr	PrepareAlign	do pass 1 prep for the align
	rts
	end

****************************************************************
*
*  Const - constant bytes
*
*  Inputs:
*	sp - pointer to the opcode
*	pc - current program counter
*
*  Outputs:
*	sp - pointer to the next opcode
*	pc - new program counter
*
****************************************************************
*
Const	private

	lda	[sp]
	and	#$00FF
	tax
	clc
	adc	pc
	sta	pc
	bcc	lb1
	inc	pc+2
lb1	txa
	sec
	adc	sp
	sta	sp
	bcc	lb2
	inc	sp+2
lb2	rts
	end

****************************************************************
*
*  DefineSegment - put the segment in the symbol table
*
*  Inputs:
*	segName - pointer to the segment name
*	segType - segment type
*	pc - current pc
*	segEntry - disp to segment entry point
*
****************************************************************
*
DefineSegment private
	using Common

	ph4	segName	push the symbol name ptr
	ph2	#0	length attribute is 0
	ph2	#'N'	push the type attribute
	lda	segType	push the private flag
	and	#$4000
	beq	lb1
	lda	#1
lb1	pha
	ph2	#1	the symbol is global
	ph2	#0	the symbol is not an expression
	clc		push the location
	lda	pc
	adc	segEntry
	tax
	lda	pc+2
	adc	segEntry+2
	pha
	phx
	lda	segType	push the data area flag
	and	#$007F
	cmp	#1
	beq	lb2
	ph2	#0
	bra	lb3
lb2	ph2	#1
lb3	ph2	#1	push the segment flag
	jsr	Define	define the symbol
	rts
	end

****************************************************************
*
*  DoOrg - set the program counter
*
*  Inputs:
*	sp - pointer to the opcode
*	pc - current program counter
*
*  Outputs:
*	sp - pointer to the next opcode
*	pc - new program counter
*
****************************************************************
*
DoOrg	private
	using OutCommon

	ldy	#1	get the value and skip the record
	lda	[sp],Y
	sta	r0
	ldy	#3
	lda	[sp],Y
	sta	r2+2
	add4	sp,#5

	sub4	r0,loadOrg	get the disp from the segment start
	cmpl	pc,r0
	bge	lb1	if the disp is greater than the pc then
	move4 r0,pc	  update the pc
lb1	anop
	rts
	end

****************************************************************
*
*  DoPass1 - Do pass 1 processing
*
*  Outputs:
*	C - set if an error occurred
*
****************************************************************
*
DoPass1	start
	using Common
;
;  Write the pass header
;
	lda	#1	pass = 1
	sta	pass
	lda	list	if list then
	beq	wp1
	puts	#'Segment:',cr=t	  print the general header
	putcr
	bra	wp2	else if progress then
wp1	lda	progress
	beq	wp2
	puts	#'Pass 1: '	  print the dot header
wp2	anop
;
;  Initialize pass dependent variables
;
	jsr	InitPass
;
;  Process segments until there are no more
;
ps1	jsr	NextSegment	get the next segment
	bcc	rt1	branch if there are no more
	jsr	DefineSegment	put the segment in the symbol table
	jsr	ListSeg	list the segname start info
	jsr	DoSegment	process this segment
	add4	pc,segSpace	add in the reserved space (if any)
	bra	ps1	next segment
;
;  Return to main
;
rt1	lda	list	if list or progress then
	bne	rt2
	lda	progress
	beq	rt3
rt2	putcr		  write a cr
rt3	anop		endif
	clc
	rts
	end

****************************************************************
*
*  DoSegment - process the opcodes in this segment
*
*  Inputs:
*	sp - pointer to the first opcode to process
*
****************************************************************
*
DoSegment private

lb1	lda	[sp]
	and	#$00FF
	asl	A
	tax
	jsr	(addr,X)
	bra	lb1

addr	dc	a'End'