Linker/pass2.asm

	keep	obj/pass2
	mcopy pass2.mac
****************************************************************
*
*  Pass 2
*
*  This module contains the subroutines used to do pass 2
*  processing of the input files and creation of the output
*  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	skip the alignment opcode and operand
	jsr	DefineAlign	do the align
	rts
	end

****************************************************************
*
*  BExpr - evaluate a local bank expression
*
*  Inputs:
*	sp - pointer to the opcode
*	pc - current program counter
*
*  Outputs:
*	sp - pointer to the next opcode
*	pc - new program counter
*
****************************************************************
*
BExpr	private
	using ExpCommon
	using OutCommon
	using Common

	stz	saveSegment	saveSegment := false
	lda	[sp]	update the PC
	xba
	and	#$00FF
	sta	expLength
lb1	add4	sp,#2	skip the op code and expression length
	ph4	sp	evaluate the expression
	jsr	Evaluate
	sta	expValue
	stx	expValue+2
	add4	loadOrg,pc,val1	make sure bank bytes match
	lda	symbolRelocatable
	beq	lb2
	add4	loadOrg,expValue,val2
	bra	lb2a
lb2	move4 expValue,val2
lb2a	stz	mask
	stz	mask+2
	short M
	ldx	expLength
	beq	lb4
	cpx	#4
	bge	lb4
	ldx	#3
	lda	#$FF
lb3	sta	mask,X
	dex
	cpx	expLength
	bge	lb3
lb4	long	M
	lda	mask
	and	val1
	sta	val1
	lda	mask+2
	and	val1+2
	sta	val1+2
	lda	mask
	and	val2
	cmp	val1
	bne	lb5
	lda	mask+2
	and	val2+2
	cmp	val1+2
	beq	lb6
lb5	ph4	#0
	ph2	#10
	jsr	Error
	bra	lb10
lb6	lda	expSegment	if the expression uses values in another
	beq	lb10	  segment then
	cmp	loadNumber
	beq	lb10
	lda	expLength	  if the expression is too short for
	cmp	#3	    a legal interseg reference then
	bge	lb7
	ph4	#0	    flag the error
	ph2	#10
	jsr	Error
	bra	lb10	    skip to "normal" processing
lb7	lda	symbolRelocatable	  if the expression is relocatable then
	beq	lb9
	jsr	DictInterseg	    create a dictionary entry
	sta	saveSegment	    save the save segment flag
	lda	shiftFlag	    if the value is shifted then
	beq	lb8
	move4 shiftValue,expValue	      use the unshifted value
lb8	anop
lb9	lda	expSegment	    if the segment is dynamic then
	jsr	IsDynamic
	bcc	lb11
	ph4	#0	      flag the error
	ph2	#17
	jsr	Error
	bra	lb11	  else
lb10	lda	symbolRelocatable	    if the expression is relocatable then
	beq	lb11
	jsr	DictReloc	      create a dictionary entry
lb11	anop		  endif

	jsr	PutValue	write an expression value
	lda	saveSegment	if saveSegment then
	beq	lb12
	sec		  save the segment number
	lda	op
	sbc	saveSegment
	sta	r0
	lda	op+2
	sbc	#0
	sta	r2
	short M
	clc
	lda	expSegment
	sta	[r0]
	long	M
lb12	brl	SkipExpression	skip the expression
;
;  Local data
;
val1	ds	4	first address
val2	ds	4	second address
mask	ds	4	bank mask
saveSegment ds 2	save segment number flag
	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]	update the program counter
	and	#$00FF
	tay
	clc
	adc	pc
	sta	pc
	bcc	lb1
	inc	pc+2
lb1	inc4	sp	skip the op code
	tyx		save the length

	tya		move the bytes
	lsr	A
	bcc	lb2
	short M
	dey
	lda	[sp],Y
	sta	[op],Y
	long	M
lb2	dey
	dey
	bmi	lb3a
lb3	lda	[sp],Y
	sta	[op],Y
	dey
	dey
	bpl	lb3
lb3a	anop
	txa		update the output pointer
	clc
	adc	op
	sta	op
	bcc	lb4
	inc	op+2
lb4	txa		update sp
	clc
	adc	sp
	sta	sp
	bcc	lb5
	inc	sp+2
lb5	rts
	end

****************************************************************
*
*  DefineAlign