From 1819b6a38e9463abd1044a5875d3da510a321191 Mon Sep 17 00:00:00 2001
From: cpg <cpg@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Sun, 3 Dec 2000 23:50:16 +0000
Subject: [PATCH] graphics memory reservation is now done via a contructor;
 some condes related changes

git-svn-id: svn://svn.cc65.org/cc65/trunk@543 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 libsrc/atari/crt0.s | 106 ++++++--------------------------------------
 1 file changed, 13 insertions(+), 93 deletions(-)

diff --git a/libsrc/atari/crt0.s b/libsrc/atari/crt0.s
index c55ad1eeb..1777db24f 100644
--- a/libsrc/atari/crt0.s
+++ b/libsrc/atari/crt0.s
@@ -10,12 +10,13 @@
 ;
 
 	.export		_exit
+	.constructor	setup_sp,26
+
 	.import		getargs, argc, argv
 	.import		initlib, donelib
        	.import	       	zerobss, pushax
 	.import		_main,__filetab,getfd
 	.import		__CODE_LOAD__, __BSS_LOAD__
-	.import		__graphmode_used
 
 	.include	"atari.inc"
 
@@ -86,31 +87,22 @@ L1:	lda	sp,x
 	tsx
 	stx	spsave
 
-; report memory usage and initialize stack pointer
+; report memory usage
 
 	lda	APPMHI
-	sta	appmsav
+	sta	appmsav			; remember old APPMHI value
 	lda	APPMHI+1
 	sta	appmsav+1
 
-	jsr	getmemtop	; adjust for graphics mode to use
-
-;	sta	sp
-	sta	APPMHI
-;	stx	sp+1		; Set argument stack ptr
+	lda	MEMTOP
+	sta	APPMHI			; initialize our APPMHI value
+	ldx	MEMTOP+1
 	stx	APPMHI+1
 
 ; Call module constructors
 
 	jsr	initlib
 
-; setup sp
-
-	lda	APPMHI
-	sta	sp
-	lda	APPMHI+1
-	sta	sp+1
-
 ; set left margin to 0
 
 	lda	LMARGN
@@ -195,91 +187,19 @@ L2:	lda	zpsave,x
 
 ; *** end of main startup code
 
+; setup sp
 
-; calc. upper memory limit to use
-
-.proc	getmemtop
-
-	ldy	__graphmode_used
-	beq	ignore		; mode 0 doesn't need adjustment
-	cpy	#32
-	bcs	ignore		; invalid value
-
-	tya
-	asl	a
-	tay
-	lda	MEMTOP
-	sec
-	sbc	grmemusage,y
-	pha
-	lda	MEMTOP+1
-	sbc	grmemusage+1,y
-	tax
-	pla
+setup_sp:
+	lda	APPMHI
+	sta	sp
+	lda	APPMHI+1
+	sta	sp+1
 	rts
 
-ignore:	lda	MEMTOP
-	ldx	MEMTOP+1
-	rts
-
-.endproc
-
 	.data
 
 zpsave:	.res	zpspace
 
-	.rodata
-
-; memory usage of the different graphics modes (0-31)
-; values < 0 of "bytes needed" are mappped to 0
-;               bytes needed    ; mode	; val. of MEMTOP
-grmemusage:
-	.word	0		; 0	; 39967
-	.word	0 ;-318		; 1	; 40285
-	.word	0 ;-568		; 2	; 40535
-	.word	0 ;-558		; 3	; 40525
-	.word	0 ;-298		; 4	; 40265
-	.word	182		; 5	; 39785
-	.word	1182		; 6	; 38785
-	.word	3198		; 7	; 36769
-	.word	7120		; 8	; 32847
-	.word	7146		; 9	; 32821
-	.word	7146		; 10	; 32821
-	.word	7146		; 11	; 32821
-	.word	162		; 12	; 39805
-	.word	0 ;-328		; 13	; 40295
-	.word	3278		; 14	; 36689
-	.word	7120		; 15	; 32847
-	.word	0		; 16	; 39967
-	.word	0 ;-320		; 17	; 40287
-	.word	0 ;-572		; 18	; 40539
-	.word	0 ;-560		; 19	; 40527
-	.word	0 ;-296		; 20	; 40263
-	.word	184		; 21	; 39783
-	.word	1192		; 22	; 38775
-	.word	3208		; 23	; 36759
-	.word	7146		; 24	; 32821
-	.word	7146		; 25	; 32821
-	.word	7146		; 26	; 32821
-	.word	7146		; 27	; 32821
-	.word	160		; 28	; 39807
-	.word	0 ;-332		; 29	; 40299
-	.word	3304		; 30	; 36663
-	.word	7146		; 31	; 32821
-
-; the program used to get these values (Atari BASIC):
-;  100 FILE=0
-;  110 IF FILE=1 THEN OPEN #1,8,0,"D:FREEMEM.OUT"
-;  120 IF FILE<>1 THEN OPEN #1,8,0,"E:"
-;  200 DIM G(32)
-;  210 FOR I=0 TO 32:GRAPHICS I:GOSUB 1000:G(I)=VAL:NEXT I
-;  220 GRAPHICS 0
-;  230 FOR I=0 TO 31:PRINT #1;I;":",G(I);" - ";G(0)-G(I):NEXT I
-;  240 CLOSE #1
-;  999 END
-;  1000 VAL=PEEK(741)+256*PEEK(742)
-;  1010 RETURN
-
 	.bss
 
 spsave:		.res	1